ELECTRICAL CONTROL AUTOMATIC TRACTION ASSISTANCE SYSTEM
BASED ON STEERING ANGLE
FIELD OF INVENTION
[001 ] The present invention relates to a traction control system, and more particularly an automatic electrical control traction assistance system, which controls the air pressure of the ride air springs of air suspension or lift axle based on steering angle, for multi-axle commercial vehicles.
BACKGROUND OF INVENTION
[002] Now a day, road systems in the developing countries are being improved continuously. However, the operating cost (cost of driver) and unavailability of operator are being increased significantly. Therefore, original equipments manufacturers are more focusing on developing heavy multi-axle commercial vehicles (such as heavy duty rigid trucks) having maximum allowable load limit in the road, so that vehicle owners can earn more income per day using these vehicles. In addition, as the competition is high in the market, original equipments manufacturers focus on developing new heavy duty rigid trucks having 10x2 and 10x4 configurations for haulage and tipping application.
[003] In general, these heavy multi-axle commercial vehicles are added with auxiliary axles either in front of the drive axle or rear side of the drive axle to increase the load carrying capacity of the multi-axle truck. The auxiliary axle is an air suspension system and is lifted in un-laden condition. If the auxiliary axle is located in-front of the drive axle, then it is called as pusher lift axle (1). If the auxiliary axle is located at the rear side of the drive axle (3), then it is called as tag lift axle.

[004] FIGS. 1(a)-1(c) show side and top views of a commercial multi-axle vehicle (MAV) having configuration of 10x2 or 10x4 with a pusher lift axle (1), in accordance with the prior art. The heavy commercial vehicle has twin front axles (2a, 2b), a pusher lift axle (1) and two rear axles (3a, 3b). In the vehicle, the twin front axles (2a, 2b) are equipped with leaf spring suspension system and the rear axles (3a, 3b) are equipped with a tandem rear leaf spring suspension. The lift axle (1) having dual tires (4) in both the sides is either located in pusher location i.e. in front of the first drive axle (3a) or tag location (not shown).
[005] The commercial multi-axle vehicle or tripper having configuration 10x2 and/or 10x4 has two front axles (2a, 2b), a pusher axle (1) and two rear axles (3a, 3b). The front axles (2a, 2b) are, namely, first front axle (2a) and second front axle (2b). The rear axles (3a, 3b) are, namely drive axle (3a) and dummy axle (3b). The pusher lift axle (1) is a non-steer air suspension and has dual tires (4). The lift axle (1) is located in front of the conventional tandem rear leaf spring suspension in a well-known manner. The front axles (2a, 2b) are steered by power steering and all the tandem rear axles (3a, 3b) are non-steer axles. Each front axle has single tire (5) on each side, whereas each rear axle (3a, 3b) having dual tires (4) on each side. The pusher lift axle (1) is assembled with dual tires (4) on each side. Therefore, the present commercial multi-axle vehicles can carry maximum allowable load in developing countries.
[006] FIG. 1(d) illustrates details of the pusher lift axle (1) mounted in front of conventional tandem leaf spring suspensions, in accordance with the prior art. The pusher lift axle (1) has a pair of ride air springs (6), a pair of lift air springs (7), a pair of top control arms and a pair of lower control arms. In addition, the pusher lift axle (1) has two tires (dual tire, 4) at each side of the axle. An automatic lift axle control system is used to operate the lift axle in laden and unladen condition, in which a dual load sensing valves are used. The design of lift axle (1) and the automatic lift axle control system are not a part of present invention. Therefore, the details are not described hereafter. In unladen

condition, the ride air spring (6) is deflated and lift air spring (7) are inflated in the lift axle, such that the lift axle is lifted-off from the road surface and is held along with its tires (4) at a desired height from the road surface.
[007] As the pusher lift axle has dual tires (4) on each side, the commercial multi-axle vehicle can carry maximum allowable load in developing countries. However, when the MAV vehicle is operated in a sever turn or sever undulated road, a lot of tire scrub problem is observed in the 10x4 or 10x2 MAV vehicle having non-steer pusher lift axle having dual tire on each sides. In particular, as three non-steer axles are mounted at the rear side of the vehicle, the pusher lift axle and tag axle tire is subjected to sever cornering forces when the vehicle experiences the sever turn. Therefore, the tires at the pusher lift axle and tag axle are subjected to tire scrubbing, which leads a shoulder scrub in the tires of pusher lift axle (2) and tag axle (3b) when the vehicle experiences the sever turn. Therefore, the life of the tire is drastically reduced.
[008] Therefore, in the multi-axle vehicle, it is highly necessaiy to minimize the shoulder scrub in the tire. In some prior art approaches, a manual traction assistance system is being conventionally used in the multi-axle vehicles, such as multi-axle coach (bus) having two rear axles and few trucks having tandem axles suspension (two rear axles). In these vehicles, the operator (i.e. driver) has to operate (i.e. switch on) the switch manually when the vehicle is experienced a sever turn and undulated roads. Thereby, the ride air springs of the auxiliary suspension is deflated for a while and inflated automatically in a pre-described time or speed of the vehicle. When deflating the ride air springs, it greatly helps in minimizing tires shoulder scrub and increasing maneuverability of the vehicle.
[009] However, in most of the real-time situations, the driver forgets to operate the manual switch especially during sever turn, the urgency of driving in the traffic maneuver, vehicle reverse condition, undulated road and slippery road, etc. Therefore,

practically, the driver could not operate the manual switch properly. Most specifically, in developing countries such as India, Pakistan China, such manual operating system is not preferable. In this regards, the operation of manual switch does not provide complete solution to minimize tires shoulder scrub, maneuverability and traction of the vehicle when the multi-axle vehicle experiences sever turn or sever undulated road. Thus, the conventional available manual traction assistance system is not desirable solution to overcome the above mentioned drawbacks and disadvantages.
[0010] Therefore, it is necessary to provide an automatic traction assistance system to overcome the above mentioned drawbacks and disadvantages, i.e. minimizing tires shoulder scrub and facilitating a better drivability (maneuverability) when the vehicle is operated during sever turn or sever undulated road.
OBJECT OF THE INVENTION
[0011] A primary object of the present invention is to provide an electrical control automatic traction assistance system for a heavy vehicle having either non-steer or steer lift axle, which is automatically and electrically operated by a steering mechanism based on a steering angle of the vehicle during sever turn.
[0012] Another object of the present invention is to provide an automatic traction assistance system for a multi-axle commercial vehicle having lift axle, which is automatically and electrically operated by a steering mechanism based on a steering angle of the vehicle during sever turn.
[0013]Another object of the present invention is to provide an automatic traction assistance system, which is capable of increasing maneuverability and traction in the drive axle when the vehicle experiences a sever turn.

10014] Another object of the present invention is to provide an automatic traction assistance system, which is capable of enhancing life of tire by reducing shoulder scrub in the tire.
SUMMARY OF THE INVENTION
[0015] An automatic traction assistance system based on steering angle of the vehicle is disclosed for a commercial multi-axle vehicle having a lift axle. This automatic traction control system works based on the movement of a steering mechanism or system of the vehicle or rotation of a steering wheel at a critical steering angle of the vehicle. Especially, it controls air pressure in ride air springs of the lift axle based on the critical steering angle of the vehicle, such that when the vehicle experiences the critical steering angle, the ride air springs of the lift axle are fully deflated or partially deflated to lift-off the lift axle along with the tires from the road surface. Thus, the automatic traction assistance system is electrically operated by the steering mechanism without any necessity of manual operations, which increases maneuverability and traction in the drive axle when the vehicle experiences a sever turn, and thus it enhances life of tire by reducing shoulder scrub in the rear tires of the vehicle.
[0016] According to the first embodiment of the present invention to achieve the object of the invention, An electrical control automatic traction assistance system is operated by the steering mechanism based on the steering angle of the vehicle having twin steer axles and a lift axle that is arranged with a pair of ride air springs and a pair of lift air springs. The automatic traction assistance system, in accordance with an exemplary first embodiment of the present invention, consists of a critical steering angle sensor, an electrical operated direction control valve, a traction assistance electrical switch (TS), a C clamp or bracket assembly and an automatic lift axle control system. Accordance to the first embodiment of the present invention, the ride air springs are fully deflated when the vehicle is experienced the critical steering angle. In this system, the direction control

valve (DCV) is pneumatically connected with a lift axle control valve and the ride air springs of the lift axle through a quick release valve to fully deflate the ride air springs when the vehicle reaches a desired steering angle during sever turn. The critical steering angle sensor is electrically connected to the DVC and is pivotally connected to a tie rod link of the steering mechanism for controlling the operation of the DVC in order to deflate the ride air springs or supply compressed air to the ride air springs. The traction switch (TS) is electrically connected to an ignition switch of the vehicle and the critical steering angle sensor for activating and deactivating the DCV.
[0017] Further, the critical steering angle sensor is secured to a vehicle frame and pivotally attached to the tie rod link that is connected between first and second drop arms of the steering mechanism. The critical steering angle sensor comprises a lever that is pivotally connected to the tie rod link through a bracket assembly. The tie rod link oscillates the lever of the critical steering angle sensor with respect to the movement of steering mechanism such that when the lever reaches the desired steering angle during sever turn, the critical steering angle sensor controls the operation of the DVC, which controls air pressure in the ride air springs in order to fully deflate the ride air springs based on the steering angle of the vehicle. The desired steering angle of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
[0018] According to second embodiment of the present invention to achieve the object of the invention, An electrical control automatic traction assistance system is operated by the steering mechanism based on the steering angle of the vehicle having twin steer axles and a lift axle that is arranged with a pair of ride air springs and a pair of lift air springs. The automatic traction assistance system, in accordance with an exemplary second embodiment of the present invention, is similar to the first embodiment of the present invention; in which the ride air springs are partially deflated instead of fully deflation the ride air springs when the vehicle is experienced the critical steering angle. In this system, a direction control valve (DVC) is pneumatically connected with a lift axle control valve

and the ride air springs of the lift axle through a quick release valve to deflate the ride air springs when the vehicle reaches a desired steering angle during sever turn. A pressure limiting valve limits air pressure in the ride air springs for partial deflation of the ride air springs while deflating the ride air springs during sever turn. An auxiliary quick release valve is pneumatically connected between the pressure limiting valve and the DCV to exhaust the compressed air from an exhaust line extended from the DCV. A critical steering angle sensor is electrically connected to the DVC and is pivotally connected to a tie rod link of the steering mechanism for controlling the operation of the DVC in order to fully or partially deflate the ride air springs or supply compressed air to the ride air springs. A traction switch (TS) is electrically connected to an ignition switch of the vehicle and the critical steering angle sensor for activating and deactivating the DCV.
[0019] The critical steering angle sensor is secured to a vehicle frame and pivotally attached to the tie rod link that is connected between first and second drop arms of the steering mechanism. The critical steering angle sensor comprises a lever that is pivotally connected to the tie rod link through a bracket assembly. The tie rod link oscillates the lever of the critical steering angle sensor with respect to the movement of steering mechanism such that when the lever reaches the desired steering angle during sever turn, the critical steering angle sensor controls the operation of the DVC, which controls air pressure in the ride air springs in order to partially or fully deflate the ride air springs based on the steering angle of the vehicle.
[0020] The pressure limiting valve is fluidly connected between an air tank and an exhaust port of the DCV through the auxiliary quick release valve. When the vehicle reaches the desired steering angle during sever turn, the critical steering angle sensor interrupts the supply of compressed air to the ride air springs through the DCV and simultaneously, the pressure limiting valve controls the exhaust port of the DCV through the auxiliary quick release valve such that air pressure is maintained in the ride air springs for partially deflating the ride air springs. The desired steering angle of the

vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
[0021] According to third embodiment of the present invention to achieve the object of the invention, An electrical control automatic traction assistance system is operated by the steering mechanism based on the steering angle of the vehicle having twin steer axles and a lift axle that is arranged with a pair of ride air springs and a pair of lift air springs. The automatic traction assistance system, in accordance with an exemplary third embodiment of the present invention, is similar to the first and second embodiments of the present invention; in which the critical steer angle sensor is secured to the frame and pivotally attached to the either first drop arm or second drop arm of the steering mechanism of the vehicle. According to the third embodiments of the present invention, when the vehicle experiences the critical steering angle, the ride air springs of non-steer lift axle are fully deflated and/or partially deflated. In this system, a direction control valve (DVC) is pneumatically connected with a lift axle control valve and the ride air springs of the lift axle through a quick release valve to deflate the ride air springs when the vehicle reaches a desired steering angle during sever turn. A pressure limiting valve limits air pressure in the ride air springs for partial deflation of the ride air springs while deflating the ride air springs during sever turn. An auxiliary quick release valve is pneumatically connected between the pressure limiting valve and the DCV to exhaust the compressed air from an exhaust line extended from the DCV. A critical steering angle sensor is electrically connected to the DVC and is pivotally connected to at least one of first and second drop arms of the steering mechanism for controlling the operation of the DVC in order to fully or partially deflate the ride air springs or supply compressed air to the ride air springs. A traction switch (TS) is electrically connected to an ignition switch of the vehicle and the critical steering angle sensor for activating and deactivating the DCV.

[0022] The critical steering angle sensor comprises a lever that is pivotally connected with the first drop arm or the second drop arm of the steering mechanism. The first or second drop arm oscillates the lever of the critical steering angle sensor with respect to the movement of steering mechanism such that when the lever reaches the desired steering angle during sever turn, the critical steering angle sensor controls the operation of the DVC, which controls air pressure in the ride air springs in order to partially or fully deflate the ride air springs based on the steering angle of the vehicle. The desired steering angle of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
[0023] According to fourth embodiment of the present invention to achieve the object of the invention, An electrical control automatic traction assistance system is operated by the steering mechanism based on the steering angle of the vehicle having twin steer axles and a lift axle that is arranged with a pair of ride air springs and a pair of lift air springs. The automatic traction assistance system, in accordance with the fourth embodiment of the present invention, is similar to the first embodiment of the present invention; in which an electronic processing unit is used in place of the critical steering angle sensor. The electronic processing unit controls the operation of an electrical operated direction control valve (i.e., the ride air springs). When the vehicle experiences the critical steering angle, the ride air springs of non-steer lift axle are partially deflated. In this system, the direction control valve (DVC) is pneumatically connected with a lift axle control valve and the ride air springs of the lift axle through a quick release valve to fully deflate the ride air springs when the vehicle reaches a desired steering angle during sever turn. A steering sensor is attached to a steering wheel of the vehicle to determine angular movement of the steering wheel. The electronic processing unit is electrically connected to the DVC and the steering sensor for controlling the operation of the DVC based on the angular movement of the steering wheel in order to deflate the ride air springs or supply compressed air to the ride air springs. A traction switch (TS) is electrically connected to

an ignition switch of the vehicle and the electronic processing unit for activating and deactivating the DCV and the electronic processing unit.
[0024] The electronic processing unit is operated with respect to the angular movement of the steering wheel such that when the vehicle reaches the desired steering angle during sever turn, the electronic processing unit converts electronic pulses from the steering sensor into electrical signals for controlling the operation of the DCV to fully deflate the ride air springs. The desired steering angle of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
[0025] According to fifth embodiment of the present invention to achieve the object of the invention, An electrical control automatic traction assistance system is operated by the steering mechanism based on the steering angle of the vehicle having twin steer axles and a lift axle that is arranged with a pair of ride air springs and a pair of lift air springs. The automatic traction assistance system, in accordance with the fifth embodiment of the present invention, is similar to the second embodiment of the present invention; in which an electronic processing unit is used in place of the critical steering angle sensor. The electronic processing unit controls the operation of an electrical operated direction control valve (i.e., the ride air springs). When the vehicle experiences a critical steering angle, the ride air springs of non-steer lift axle are fully deflated. In this system, the direction control valve (DVC) is pneumatically connected with a lift axle control valve and the ride air springs of the lift axle through a quick release valve to deflate the ride air springs when the vehicle reaches a desired steering angle during sever turn. A pressure limiting valve limits air pressure in the ride air springs for partial deflation of the ride air springs while deflating the ride air springs during sever turn. An auxiliary quick release valve is pneumatically connected between the pressure limiting valve and the DCV to exhaust the compressed air from an exhaust line extended from the DCV. A steering sensor is attached to a steering wheel of the vehicle to determine angular movement of the steering wheel. The electronic processing unit is electrically connected to the DVC

and the steering sensor for controlling the operation of the DVC based on the angular movement of the steering wheel in order to fully or partially deflate the ride air springs or supply compressed air to the ride air springs. A traction switch (TS) is electrically connected to an ignition switch of the vehicle and the electronic processing unit for activating and deactivating the DCV and the electronic processing unit.
[0026] The electronic processing unit is operated with respect to the angular movement of the steering wheel such that when the vehicle reaches the desired steering angle during sever turn, the electronic processing unit converts electronic pulses from the steering sensor into electrical signals for controlling the operation of the DCV to fully or partially deflate the ride air springs. The desired steering angle of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS:
[0027] The objects and advantages of the present invention will appear herein after as this disclosure progresses, reference being had to the accompanying drawings, in which:
[0028] FIGS. 1(a)-1(c) show side and top views of a commercial multi-axle vehicle (MAV) having configuration of 10x2 or 10x4 with a pusher lift axle, in accordance with the prior art;
[0029]FIG. 1(d) illustrates details of a pusher lift axle mounted in front of conventional tandem leaf spring suspensions, in accordance with the prior art;
[0030] FIG. 2 illustrates a schematic view of an electrical control automatic traction assistance system based on steering angle of a vehicle, in accordance with an exemplary first embodiment of the present invention;

[0031] FIG. 3 illustrates a schematic view of an electrical control automatic traction assistance system based on steering angle of a vehicle, in accordance with an exemplary second embodiment of the present invention;
[0032] FIGS. 4(a) and 4(b) respectively illustrate a schematic view of a steering mechanism and an attachment of critical steering sensor with the steering mechanism of a commercial multi-axle vehicle, in accordance with exemplary first and second embodiments of the present invention;
[0033] FIGS. 5(a) and 5(b) illustrate a schematic view of critical steering angles of the commercial multi-axle vehicle at left-hand (Lli) turn and right-hand (RH) turn, respectively, in accordance with all exemplary embodiments of the present invention;
[0034] FIG. 6 illustrates a schematic view of working principles of the critical steering angle sensor of the commercial multi-axle vehicle, in accordance with the exemplary First, second and third embodiments of the present invention;
[0035] FIG. 7 illustrates details of the attachment of critical steering sensor with a tie rod link of the steering mechanism of the commercial multi-axle vehicle, in accordance with exemplary first and second embodiments of the present invention;
[0036]FIGS. 8(a) and 8(b) illustrate a schematic view of a steering mechanism and an attachment of critical steering sensor with the steering mechanism of a commercial multi-axle vehicle, in accordance with an exemplary third embodiment of the present invention;

[0037] FIG. 9 illustrates details of the attachment of critical steering sensor with a first drop arm of the steering mechanism of the commercial multi-axle vehicle, in accordance with the exemplary third embodiment of the present invention;
[0038] FIG. 10 illustrates a schematic view of an electrical control automatic traction assistance system based on steering angle of a vehicle, in accordance with an exemplary fourth embodiment of the present invention; and
[0039] FIG. 11 illustrates a schematic view of an electrical control automatic traction assistance system based on steering angle of a vehicle, in accordance with an exemplary fifth embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0040] The present invention provides an automatic electrical control traction assistance system associated with a lift axle (pusher lift axle) of a heavy commercial multi-axle vehicle having configuration 10x2 and 10x4 with twin steer axles, where the lift axle, i.e. pusher lift axle, is arranged with a pair of ride air springs (6) and a pair of lift air springs (7). It can be used for multi-axle couch and tractor trailer has either pusher or tag non-steer air suspension. The heavy commercial multi-axle vehicles are hereafter referred as vehicle only for the purpose of explanation, but not by the way of any limitations. The automatic electrical control traction assistance system of the present invention is controlled by a steering mechanism of the vehicle. It is especially an electrical type system attached with the steering system of the vehicle. In addition, it is electrically connected with a lift axle control system used in the multi-axle commercial vehicle. The design of lift axle (1) and the automatic lift axle control system are not a part of the present invention, where these details are known in the art and therefore not described hereafter in detail. Similar reference numerals for same components or parts are being

marked and referred in all the embodiments of the present invention as well as from prior art illustrations only for the purpose of easy understanding of the invention, but it is not
by the way of any limitations.
[0041] More specially, the automatic traction assistance system of the present invention is attached to the existing multi-axle commercial vehicle and is controlled by the steering mechanism of the vehicle, which controls air pressure of the ride air springs of the air suspension or lift axle based on steering angle. In particular, this automatic traction control system works based on the movement of a steering mechanism or system of the vehicle or rotation of a steering wheel at a critical steering angle of the vehicle. The critical steering angle of the vehicle is desired and preset within a maximum steering angle of a vehicle wheel at its steered direction (left or right direction). Especially, it controls air pressure in ride air springs of the lift axle based on the critical steering angle of the vehicle, such that when the vehicle experiences the critical steering angle, the ride air springs of the lift axle are fully deflated or partially deflated to lift-off the lift axle along with the tires from the road surface. Thus, the automatic traction assistance system is electrically operated by the steering mechanism without any necessity of manual operations, which increases maneuverability and traction in the drive axle when the vehicle experiences a sever turn, and thus it enhances life of tire by reducing shoulder scrub in the rear tires of the vehicle, i.e. reducing shoulder scrub of tire for the heavy duty multi-axle vehicle having a pusher lift axle and tandem rear spring suspension.
[0042] FIG. 2 illustrates a schematic view of an electrical control automatic traction assistance system (11) based on a steering angle of a vehicle, in accordance with an exemplary first embodiment of the present invention. The electrical control automatic traction assistance system (11) is operated by the steering mechanism (34) based on the steering angle of the vehicle, where the vehicle is a commercial multi-axle vehicle having twin steer axles and a lift axle or pusher lift axle (1) that is arranged with the pair of ride air springs (6) and the pair of lift air springs (7). This electrical control automatic traction

control system (11) controls the air pressure of the ride air springs (6) of the lift axle (1) based on the critical steering angle (8) of the vehicle. When the vehicle experiences the critical steering angle (8), the ride air springs (6) of the non-steer pusher lift axle (1) are fully deflated to lift-off the lift axle (1) with its tires from the road surface.
[0043] The electrical control automatic traction assistance system (11), in accordance with an exemplary first embodiment of the present invention, consists of an electrically operated critical steering angle sensor (23), an electrical operated direction control valve (DCV, 10), a traction assistance electrical switch (TS, 12), a C clamp or bracket assembly (13) and an automatic lift axle control system (28), where the automatic lift axle control system (28) is a part of existing art.
[0044] The electrical control automatic traction assistance system (11) is fluidly (pneumatically) connected with the lift axle control system (28) of the vehicle having a tandem leaf spring suspension. While connecting the automatic traction assistance system (11) to the lift axle control system (28), the direction control valve (10) is fluidly connected with a lift axle control valve (LACV, 14) of the automatic lift axle control system (28) and the ride air springs (6) of the lift axle (1) through a quick release valve (QRV, 18). In particular, a first outlet port (15) of the LACV (14) is fluidly connected with an inlet port (16) of the normally open electrically operated direction control valve (10) through a fluid line (29). Similarly, an outlet port (17) of the direction control valve (10) is fluidly connected to the ride air springs (6) of the lift axle (1) through the quick release valve (QRV, 18) via a fluid line (30). As the direction control valve (10) is normally opened, the inlet port (16) and the outlet port (17) of the direction control valve (10) and an inlet port (19) and outlet ports (20) of the quick release valve (18) are opened until an electrical signal received from a solenoid which is a part of the DCV (10).

[0045] The traction assistance switch (12, TS) is electrically connected to an ignition switch. IG (21) of the vehicle through a wire (22) and the critical steering angle sensor (23) through a wire (24) for activating or deactivating the DCV (10) by operating the critical steering angle sensor (23). The critical steering angle sensor (23) is electrically connected to the DVC (10) for controlling the operation of the DVC (10) in order to fully deflate the ride air springs (6) or supply compressed air to the ride air springs (6). Especially, the solenoid of the electrically operated direction control valve (10, DCV) is electrically connected with the critical steering angle sensor (23) through a wire (25). Once the electric signal is received by the DCV (10) from the critical steering angle sensor (23) when the vehicle reaches the critical steering angle (8) during sever turn, the outlet port (17) of the electrically operated direction control valve (10, DCV) is connected to an exhaust port (26) of the DCV (10), so that the ride air springs (6) are fully deflated.
[0046] FTG. 3 illustrates a schematic view of an electrical control automatic traction assistance system (11a) based on steering angle of the vehicle, in accordance with an exemplary second embodiment of the present invention. The electrical control automatic traction assistance system (11a) is operated by the steering mechanism (34) based on the steering angle of the vehicle, where the vehicle is a commercial multi-axle vehicle having twin steer axles and a lift axle or pusher lift axle (1) that is arranged with the pair of ride air springs (6) and the pair of lift air springs (7). This automatic traction assistance system (11a) controls the air pressure of the ride air springs (6) of the lift axle (1) based on the critical steering angle (8) of the vehicle. When the vehicle experiences the critical steering angle (8), the ride air springs (6) of the lift axle are fully or partially deflated. Similar reference numerals for same components or parts are being marked and referred in all the embodiments of the present invention as well as from prior art illustrations only for the purpose of easy understanding of the invention, but it is not by the way of any limitations.

[0047] The electrical control automatic traction assistance system (11a), in accordance with an exemplary second embodiment of the present invention, consists of an electrically operated critical steering angle sensor (23), an electrical operated direction control valve (10), a traction assistance electrical switch (TS, 12), a pressure limiting valve (27), an auxiliary quick release valve (QRV, 31), a C clamp or bracket assembly (13) and an automatic lift axle control system (28).
[0048] The electrical control automatic traction assistance system (11a) is fluidly (pneumatically) connected with the lift axle control system (28) of the vehicle having a tandem leaf spring suspension. While connecting the automatic traction assistance system (1 la) to the lift axle control system (28), the direction control valve (10) is fluidly connected with the lift axle control valve (LACV, 14) of the automatic lift axle control system (28) and the ride air springs (6) of the lift axle (1) through a quick release valve (QRV, 18). In particular, a first outlet port (15) of the TACV (14) is fluidly connected with an inlet port (16) of the normally open electrically operated direction control valve (DCV, 10) through a fluid line (29). Similarly, an out let port (17) of the direction control valve (10) is fluidly connected to the ride air springs (6) of the lift axle (1) through the quick release valve (QRV, 18) via a fluid line (30). As the direction control valve (10) is normally opened, the inlet port (16) and the outlet port (17) of the DCV (10) and an inlet port (19) and outlet ports (20) of the quick release valve (18) are opened until the electrical signal received from a solenoid which is a part of the DCV (10).
[0049] An exhaust port (26) of the DCV (10) is fluidly connected to the pressure limiting valve (27) through the auxiliary quick release valve (31). The pressure limiting valve (27) is connected to an air tank (32) through a fluid line (33). The pressure liming valve (27) is configured to maintain a required or desired air pressure in the ride air springs (6) while deflating the ride air springs (6) for partial deflation of the ride air springs (6) when the vehicle reaches the critical steering angle (8) during sever turn. The auxiliary quick release valve (31) is pneumatically connected between the pressure limiting valve (27)

and the DCV (10) to exhaust the compressed air from an exhaust line extended from the exhaust port (26) of the DCV (10).
[0050] The traction assistance switch (TS, 12) is electrically connected to the ignition switch, IG (21) of the vehicle through a wire (22) and the critical steering angle sensor (23) through a wire (24) for activating or deactivating the DCV (10) by operating the critical steering angle sensor (23). The critical steering angle sensor (23) is electrically connected to the DVC (10) for controlling the operation of the DVC (10) in order to fully or partially deflate the ride air springs (6) or supply compressed air to the ride air springs (6). Especially, the solenoid of the electrically operated direction control valve (DCV, 10) is electrically connected with the critical steering angle sensor (23) through a wire (25). Once the electric signal is received by the DCV (10) from the critical steering angle sensor (23) when the vehicle reaches the critical steering angle (8) during sever turn, the outlet port (17) of the direction control valve (10) is connected to the exhaust port (26) of the DCV (10) so that the pressure limiting valve controls the auxiliary quick release valve (31) to partially or fully exhaust the compressed air from the exhaust port (26) of the DCV (10) in order to maintain or limit a required or desired air pressure in the ride air springs (6) while deflating the ride air springs (6), which leads to partial or complete deflation of the ride air springs (6) when the vehicle reaches the critical steering angle (8) during sever turn. In particular, when the vehicle reaches the desired steering angle (8) during sever turn, the critical steering angle sensor (23) interrupts the supply of compressed air to the ride air springs (6) through the DCV (10) and simultaneously, the pressure limiting valve (27) controls the exhaust port (26) of the DCV (10) through the auxiliary quick release valve (31) such that air pressure is maintained in the ride air springs (6) for partially deflating the ride air springs (6).
[005 3] FIGS. 4(a) and 4(b) respectively illustrate a schematic view of a steering mechanism (34) and attachment of the critical steering sensor (23) with the steering mechanism (34) of the commercial multi-axle vehicle, in accordance with exemplary first

and second embodiments of the present invention. The critical steering sensor (23) is secured with a vehicle frame (35) and pivotally connected with a tie rod link (36) of the steering mechanism (34), where the tie rod link (36) is connected between first and second drop arms (39a, 39b) of the steering mechanism (34). When the vehicle is operated and steered using a steering wheel (42) of the steering mechanism (34), the steering linkage mechanism (34) oscillates the tie rod link (36) such that a lever (37) (as shown in Fig. 6) of the critical steering sensor (23) also oscillates as it is secured to the tie rod link (36).
[0052] FIGS. 5(a) and 5(b) illustrate a schematic view of critical steering angles of the commercial multi-axle vehicle at left-hand (LH) turn and right-hand (RH) turn, respectively, in accordance with all exemplary embodiments of the present invention. The critical steer angle (8) is an angle at which the shoulder scrub starts in the tires when the vehicle is experiences a hard turns in both the RH and LH turn, where the critical steer angle (8) of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction, i.e. left or right direction of steering of the front axle by the steering mechanism when the vehicle experiences sever turn.
[0053]FIG. 6 illustrates a schematic view of working principles of the critical steering angle sensor (23) of the commercial multi-axle vehicle, in accordance with the exemplary first, second and third embodiments of the present invention. The lever (37) of the critical steering angle sensor (23) is connected to the tie rod link (36) of the steering mechanism, such that the lever (37) oscillates with respect to pivot joints. The tie rod link (36) oscillates the lever (37) of the critical steering angle sensor (23) with respect to the movement of steering mechanism (34) such that when the lever (37) reaches the desired steering angle (8) during sever turn, the critical steering angle sensor (23) controls the operation of said DVC (10), which controls air pressure in the ride air springs (6) in order to fully or partially deflate the ride air springs (6) based on the steering angle of the

vehicle. When the angular movement of lever (37) is oscillated within the critical steer angle while turning the vehicle at right-hand or left-hand side direction, the critical steer angle sensor (23) senses as no sever turn of the vehicle and supplies no electrical signal to the solenoid of the DCV (10). When the angular movement of the lever (37) reaches (while swinging) to equal magnitude and greater angle than critical steer angle while turning the vehicle at right-hand or left-hand side direction, the critical steer angle sensor (23) senses as sever turn of the vehicle and supplies the electrical signal to the DCV (10). When the electrical energy is supplied to the solenoid of the DCV (10), the DCV is electrically charged such that the outlet port (17) is opened to the exhaust port (26) of the DCV (10) to fully deflate the ride air springs (6). Similarly, when the electrical energy is supplied to the solenoid of the DCV (10), the DCV is electrically charged such that the outlet port (17) is opened to the exhaust port (26) of the DCV (10). Then, the compressed air is supplied from the pressure limiting valve, PLV (27) to the ride air springs (6), such that the PLV (27) limits or controls the air pressure in the ride air springs (6) in order to partially deflate the ride air springs (6).
[0054] FIG. 7 illustrates details of the steering mechanism (34) and the attachment of critical steering sensor (23) with the tie rod link (36) of the steering mechanism (34) of the commercial multi-axle vehicle, in accordance with exemplary first and second embodiments of the present invention. The critical steering sensor (23) is attached to the vehicle frame (35) and pivotally attached to the tie rod link (36) of the steering mechanism (34). The lever (37) of the critical steering sensor (23) is pivotally connected to a link which has spherical joints at both the ends. The other end of the link is pivotally connected to the C clamp or bracket assembly (13), where the C clamp or bracket assembly (13) is secured to the tie rod link (36) of the steering mechanism.
[0055] FIGS. 8(a) and 8(b) illustrate a schematic view of the steering mechanism (34) and the attachment of the critical steering sensor (23) with the steering mechanism of the commercial multi-axle vehicle, in accordance with an exemplary third embodiment of the

present invention. The automatic traction assistance system (lib) based on steering angle of the vehicle according to the third embodiment of the present invention is similar to the first and second embodiments of the present invention. The automatic traction assistance system (lib) according to the third embodiment comprises all the components and parts described and illustrated in the first and second embodiments of the present invention, but in this system, the critical angle sensor (23) is pivotally connected with either first drop arm (39a) or second drop arm (39b) of the steering mechanism (34) of the vehicle instead of pivotally connected with the tie rod link of the steering mechanism, as shown in Fig. 8(b). In particular, the critical steering sensor (23) is secured with the vehicle frame (35), where the lever (37) of the critical steering sensor (23) is pivotally connected with either the first drop arm (39a) or the second drop arm (39b) of the steering mechanism (34). When the vehicle is operated and steered using a steering wheel (42) of the steering mechanism (34), the steering linkage mechanism (34) oscillates the drop arms (39a, 39b) such that the lever (37) of the critical steering sensor (23) also oscillates as it is secured to the one of the drop arms (39a, 39b).
[0056] FIG. 9 illustrates details of the steering mechanism (34) and the attachment of the critical steering sensor (23) with the first drop arm (39a) of the steering mechanism of the commercial multi-axle vehicle, in accordance with the exemplary third embodiment of the present invention. The lever (37) of the critical steering sensor (23) is pivotally connected to a link which has spherical joints at both the ends. The other end of the link is pivotally connected to the first drop arm (39a) of the steering mechanism (34). When the vehicle is operated in straight ahead, the critical steer angle sensor (9) does not supply electrical signal. When the vehicle is operated in a sever turn, the critical steer angle sensor (23) supplies electrical energy to the DCV (10). Therefore, if the third embodiment is used with the first embodiment, the ride air springs (6) are fully deflated. If the third embodiment is used with the second embodiment, the ride air springs (6) are partially deflated. In particular, either the first drop arm (39a) or the second drop arm (39b) oscillates the lever (37) of the critical steering angle sensor (23) with respect to the

movement of steering mechanism (34) such that when the lever (37) reaches the desired steering angle (8) during sever turn, the critical steering angle sensor (23) controls the operation of said DVC (10), which controls air pressure in the ride air springs (6) in order to partially or fully deflate the ride air springs (6) based on the steering angle of the vehicle.
[0057] FIG. 10 illustrates a schematic view of an electrical control automatic traction assistance system (lie) based on steering angle of the vehicle, in accordance with an exemplary fourth embodiment of the present invention. The electrical control automatic traction assistance system (lie) is operated by the steering mechanism (34) based on the steering angle of the vehicle, where the vehicle is a commercial multi-axle vehicle having twin steer axles and a lift axle or pusher lift axle (1) that is arranged with the pair of ride air springs (6) and the pair of lift air springs (7). The electrical control automatic traction assistance system (lie), in accordance with the exemplary fourth embodiment of the present invention, consists of an electrical operated direction control valve (10), a traction assistance electrical switch (TS, 12), an electronic processing unit (40), a commercial steering sensor (41) and an automatic lift axle control system (28), where the automatic lift axle control system (28) is a part of existing art.
[0058]The electrical control automatic traction assistance system (lie) is fluidly (pneumatically) connected with the lift axle control system (28) of the vehicle having a tandem leaf spring suspension. While connecting the automatic traction assistance system to the lift axle control system (28), the DCV (10) is connected as similar to the first embodiment of the present invention, i.e. the direction control valve (10) is fluidly connected with a lift axle control valve (LACV, 14) of the automatic lift axle control system (28) and the ride air springs (6) of the lift axle (1) through a quick release valve (QRV, 18). In particular, a first outlet port (15) of the LACV (14) is fluidly connected with an inlet port (16) of the normally open electrically operated direction control valve (10) through a fluid line (29). Similarly, an outlet port (17) of the direction control valve

(10) is fluidly connected to the ride air springs (6) of the lift axle (1) through the quick release valve (QRV, 18) via a fluid line (30). As the direction control valve (10) is normally opened, the inlet port (16) and the outlet port (17) of the direction control valve (10) are opened until an electrical signal received from a solenoid which is a part of the DCV(IO).
[0059] The steering sensor (41) is attached to a steering wheel (42) of the vehicle to determine angular movement of the steering wheel while turning the vehicle in normal and sever turn in both right-hand and left-hand directions. The steering sensor (41) sends output in the form of electronic pulses. The electronic processing unit (40) is electrically connected to the DVC (10) through an electrical wire (44) and the steering sensor (41) for controlling the operation of the DVC (10) based on the angular movement of the steering wheel (42) sensed by the steering sensor (41), which fully deflates the ride air springs (6) or supply compressed air to the ride air springs (6). The electronic processing unit (40) is electrically connected to the ignition switch, IG (21) of the vehicle through the traction switch, TS (12) using an electrical wire (43). The traction switch (TS, 12) is used for activating and deactivating the DCV (10) and the electronic processing unit (40).
[ 0060] The electronic processing unit (40) is configured to convert the electronic pulses received from the steering sensor (41) into the electrical signals, and to send these electrical signals to the solenoid of the DCV (10) through the electric wire (44) based on the angular movement of the steering wheel (42) (i.e. steering angle of the vehicle) sensed by the steering sensor (41). When the vehicle is operated in straight ahead or not experiences any sever turn, i.e. not reaches the critical steering angle (8), the electronic processing unit (40) does not send any electrical signal to the solenoid of the DCV (10). When the vehicle is operated in a sever turn, i.e. the vehicle reaches the critical steering angle (8) during sever turn, the electronic processing unit (40) sends or transmits electrical signals to the solenoid of the DCV (10) such that the outlet port (17) is opened to the exhaust port (26) of the DCV (10) to exhaust the compressed air from the ride air

springs (6). Thereby, the ride air springs (6) of the lift axle (1) are fully deflated to lift-off the lift axle with its tires from the road surface according to the fourth embodiment of the present invention.
[0061] FIG. II illustrates a schematic view of an electrical control automatic traction assistance system (lid) based on steering angle of the vehicle, in accordance with an exemplary fifth embodiment of the present invention. The electrical control automatic traction assistance system (lid) is operated by the steering mechanism (34) based on the steering angle of the vehicle, where the vehicle is a commercial multi-axle vehicle having twin steer axles and a lift axle or pusher lift axle (1) that is arranged with the pair of ride air springs (6) and the pair of lift air springs (7). The electrical control automatic traction assistance system (lid), in accordance with an exemplary fifth embodiment of the present invention, consists of an electrical operated direction control valve (10), a traction assistance electrical switch (TS, 12), an electronic processing unit (40), a commercial steering sensor (41), a pressure limiting valve (27), an auxiliary quick release valve (31) and an automatic lift axle control system (28), where the automatic lift axle control system (28) is a part of existing art.
[0062]The electrical control automatic traction assistance system (lid) is fluidly (pneumatically) connected with the lift axle control system (28) of the vehicle having a tandem leaf spring suspension. While connecting the automatic traction assistance system to the lift axle control system (28), the DCV (10) is connected as similar to the first and second embodiments of the present invention, i.e. the direction control valve (10) is fluidly connected with a lift axle control valve (LACV, 14) of the automatic lift axle control system (28) and the ride air springs (6) of the lift axle (1) through a quick release valve (QRV, 18). In particular, a first outlet port (15) of the LACV (14) is fluidly connected with an inlet port (16) of the normally open electrically operated direction control valve (10) through a fluid line (29). Similarly, an outlet port (17) of the direction control valve (10) is fluidly connected to the ride air springs (6) of the lift axle (1)

through the quick release valve (QRV, 18) via a fluid line (30). As the direction control valve (10) is normally opened, the inlet port (16) and the outlet port (17) of the direction control valve (10) are opened until an electrical signal received from a solenoid which is apartoftheDCV(lO).
[0063] The fifth embodiment is similar to the fourth embodiment where the pressure limiting valve (27) and the auxiliary quick release valve (31) are incorporated. The pressure limiting valve (27) and a quick release valve (31) are used to limit the air pressure in the ride air springs (6) for partial deflation of the ride air springs (6) while deflating the ride air springs during sever turn. An exhaust port (26) of the DCV (10) is fluidly connected to the pressure limiting valve (27) through the auxiliary quick release valve (31). The pressure limiting valve (27) is connected to an air tank (32) through a fluid line (45). The auxiliary quick release valve (31) is pneumatically connected between the pressure limiting valve (27) and the DCV (10) to exhaust the compressed air from an exhaust line extended from the exhaust port (26) of the DCV (10). The pressure liming valve (27) is configured to maintain or limit compressed air in a required or desired air pressure in the ride air springs (6) while deflating the ride air springs (6), which provides partial deflation of the ride air springs (6) when the vehicle reaches the critical steering angle (8) during sever turn. So that, according to the fifth embodiment, the ride air springs (6) are partially deflated and also fully deflated. Therefore, the cornering force reaction on the lift axle (1) is reduced drastically to prevent the scrub in the tires during sever turn.
[0064] The steering wheel sensor (41) is attached to the steering wheel (42) of the vehicle to determine angular movement of the steering wheel while turning the vehicle in normal and sever turn in both right-hand and left-hand directions. The steering sensor (41) sends output in the form of electronic pulses. The electronic processing unit (40) is electrically connected to the DVC (10) through an electrical wire (44) and the steering sensor (41) for controlling the operation of the DVC (10) based on the angular movement of the steering

wheel (42) sensed by the steering sensor (41), which fully or partially deflates the ride air springs (6) or supply compressed air to the ride air springs (6). The electronic processing unit (40) is electrically connected to the ignition switch, IG (21) of the vehicle through the traction switch, TS (12) using an electrical line (43). The traction switch (TS, 12) is used for activating and deactivating the DCV (10) and the electronic processing unit (40).
[0065] The electronic processing unit (40) is configured to convert the electronic pulses received from the steering sensor (41) into the electrical signals, and to send these electrical signals to the solenoid of the DCV (10) whenever required through the electric wire (44) based on the angular movement of the steering wheel (42) (i.e. steering angle of the vehicle) sensed by the steering sensor (41). When the vehicle is operated in straight ahead or not experiences any sever turn, i.e. not reaches the critical steering angle (8), the electronic processing unit (40) does not send any electrical signal to the solenoid of the DCV (10). When the vehicle is operated in a sever turn, i.e. the vehicle reaches the critical steering angle (8) during sever turn, the electronic processing unit (40) sends or transmits electrical signals to the solenoid of the DCV (10).
[0066] Once the electric signal is received by the DCV (10), the outlet port (17) of the direction control valve (10) is opened to the exhaust port (26) of the DCV (10) to exhaust the compressed air from the ride air springs (6) so that the pressure limiting valve controls the auxiliary quick release valve (31) to partially or fully exhaust the compressed air from the exhaust port (26) of the DCV (10) in order to maintain or limit a required or desired air pressure in the ride air springs (6) while deflating the ride air springs (6), which leads to partial or complete deflation of the ride air springs (6) when the vehicle reaches the critical steering angle (8) during sever turn. Thereby, the ride air springs (6) of the lift axle (1) are partially or fully deflated according to the fifth embodiment of the present invention.

[0067] The electrical automatic traction control system of all the embodiments of the present invention increases the traction automatically in the vehicle when the vehicle experiences a sever turn. In the present design of the electrical automatic traction control system, the ride air springs (6) are either fully or partially deflated when the vehicle experiences the critical steering angle (8), so that the reaction load on the pusher lift axle (1) is reduced significantly until the front steering wheel return to the steering angle less than the critical steering angle (8). The present invention of the automatic traction control system uses the steering sensor (41) fitted in the steering wheel (42) for either fully or partially deflating the ride air springs (6) when the vehicle experiences the critical steering angle (8). The present invention of the automatic traction control system works based on the movement of the steering linkage mechanism of the vehicle. Especially, the automatic traction control system controls the air pressure of the ride air springs (6) of the lift axle based on the steering angle of the vehicle. Thus, the present invention increases the maneuverability of the vehicle automatically when required (a sever turning). Therefore, the shoulder scrub and the wear of the tire are significantly reduced.
[0068] The present invention is a fully automatic traction control system which is used to extend the tire life of the vehicle having non-steer lift axle (or air suspension) and to control the traction of the vehicle. This automatic traction control system works based on the movement of the steering angle of the vehicle. Especially, the automatic traction control system controls the air pressure of the ride air springs (6) of the lift axle (1) based on the steering angle of the vehicle. The automatic traction control system is controlled and operated based on the steering system of the vehicle, which is the scope of the present invention. The steering of the vehicle may be taken as inputs from either front axles steering linkages (i.e., drop arms, drag links, steering arms etc.,) or electrical or electronic signals such as steering wheel sensors, electrical limit switches, etc. Therefore, the present invention is not limited to the embodiments here in before described which may be varied in both construction and detail within the scope of the appended claims. Many modifications and other embodiments of the invention may come to mind to one

skilled in the art to which this invention pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. In addition, some changes (such as adding new valves and deleting few valves) may be made to these specific embodiments, and such modifications are contemplated by the principle of the present invention. In addition, it is to be understood that the present invention is applicable for all the range of commercial trucks having steer and/or non-steer pusher or tag air suspension and multi-axle couch having non-steer pusher or tag air suspension. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims.

WE CLAIM:
1. An electrical control automatic traction assistance system (11) being operated by a steering mechanism (34) based on a steering angle of a vehicle having twin steer axles and a lift axle (1) that is arranged with a pair of ride air springs (6) and a pair of lift air springs (7), comprising:
a direction control valve (DVC, 10) pneumatically connected with a lift axle control valve (14) and the ride air springs (6) of the lift axle (1) through a quick release valve (18) to fully deflate the ride air springs (6) when the vehicle reaches a desired steering angle (8) during sever turn;
a critical steering angle sensor (23) electrically connected to the DVC (10) and pivotally connected to a tie rod link (36) of the steering mechanism (34) for controlling the operation of said DVC (10) in order to deflate the ride air springs (6) or supply compressed air to the ride air springs (6); and
a traction switch (TS, 12) electrically connected to an ignition switch (21) of the vehicle and the critical steering angle sensor (23) for activating and deactivating the DCV (10).
2. The system of claim 1, wherein the critical steering angle sensor (23) is secured to a vehicle frame (35) and pivotally attached to the tie rod link (36) that is connected between first and second drop arms (39a, 39b) of the steering mechanism (34).
3. The system of claims 1 and 2, wherein the critical steering angle sensor (23) comprises a lever (37) that is pivotally connected to the tie rod link (36) through a bracket assembly (13).
4. The system of claims 1 to 3, wherein the tie rod link (36) oscillates the lever (37) of the critical steering angle sensor (23) with respect to the movement of steering mechanism (34) such that when the lever (37) reaches the desired steering angle (8)

during sever turn, the critical steering angle sensor (23) controls the operation of said DVC (10), which controls air pressure in the ride air springs (6) in order to fully deflate the ride air springs (6) based on the steering angle of the vehicle.
5. The system of claims 1 to 4, wherein the desired steering angle (8) of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
6. An electrical control automatic traction assistance system (11a) being operated by a steering mechanism (34) based on a steering angle of a vehicle having twin steer axles and a lift axle (1) that is arranged with a pair of ride air springs (6) and a pair of lift air springs (7), comprising:
a direction control valve (DVC, 10) pneumatically connected with a lift axle control valve (14) and the ride air springs (6) of the lift axle (1) through a quick release valve (18) to deflate the ride air springs (6) when the vehicle reaches a desired steering angle (8) during sever turn;
a pressure limiting valve (27) for limiting air pressure in the ride air springs (6) for partial deflation of the ride air springs (6) while deflating the ride air springs (6) during sever turn;
an auxiliary quick release valve (31) pneumatically connected between the pressure limiting valve (27) and the DCV (10) to exhaust the compressed air from an exhaust line extended from the DCV (10);
a critical steering angle sensor (23) electrically connected to the DVC (10) and pivotally connected to a tie rod link (36) of the steering mechanism (34) for controlling the operation of said DVC (10) in order to fully or partially deflate the ride air springs (6) or supply compressed air to the ride air springs (6); and
a traction switch (TS, 12) electrically connected to an ignition switch (21) of the vehicle and the critical steering angle sensor (23) for activating and deactivating the DCV (10).

7. The system of claim 6, wherein the critical steering angle sensor (23) is secured to a vehicle frame (35) and pivotally attached to the tie rod link (36) that is connected between first and second drop arms (39a, 39b) of the steering mechanism (34).
8. The system of claims 6 and 7, wherein the critical steering angle sensor (23) comprises a lever (37) that is pivotally connected to the tie rod link (36) through a bracket
assembly (13).
9. The system of claims 6 to 8, wherein the tie rod link (36) oscillates the lever (37) of the critical steering angle sensor (23) with respect to the movement of steering mechanism (34) such that when the lever (37) reaches the desired steering angle (8) during sever turn, the critical steering angle sensor (23) controls the operation of said DVC (10), which controls air pressure in the ride air springs (6) in order to partially or fully deflate the ride air springs (6) based on the steering angle of the vehicle.
10. The system of claim 1, wherein the pressure limiting valve (27) is fluidly connected between an air tank (32) and an exhaust port (26) of the DCV (10) through the auxiliary quick release valve (31).
11. The system of claims 1 and 10, wherein when the vehicle reaches the desired steering angle (8) during sever turn, the critical steering angle sensor (23) interrupts the supply of compressed air to the ride air springs (6) through the DCV (10) and simultaneously, the pressure limiting valve (27) controls the exhaust port (26) of the DCV (10) through the auxiliary quick release valve (31) such that air pressure is maintained in the ride air springs (6) for partially deflating the ride air springs (6).
12. The system of claims 6 to 11, wherein the desired steering angle (8) of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.

13. An electrical control automatic traction assistance system (Ufa) being operated by a steering mechanism (34) based on a steering angle of a vehicle having twin steer axles and a lift axle (1) that is arranged with a pair of ride air springs (6) and a pair of lift air springs (7), comprising:
a direction control valve (DVC, 10) pneumatically connected with a lift axle control valve (14) and the ride air springs (6) of the lift axle (1) through a quick release valve (18) to deflate the ride air springs (6) when the vehicle reaches a desired steering angle (8) during sever turn;
a pressure limiting valve (27) for limiting air pressure in the ride air springs (6) for partial deflation of the ride air springs (6) while deflating the ride air springs during sever turn;
an auxiliary quick release valve (31) pneumatically connected between the pressure limiting valve (27) and the DCV (10) to exhaust the compressed air from an exhaust line extended from the DCV (10);
a critical steering angle sensor (23) electrically connected to the DVC (10) and pivotally connected to at least one of first and second drop arms (39a, 39b) of the steering mechanism (34) for controlling the operation of said DVC (10) in order to fully or partially deflate the ride air springs (6) or supply compressed air to the ride air springs (6); and
a traction switch (TS, 12) electrically connected to an ignition switch (21) of the vehicle and the critical steering angle sensor (23) for activating and deactivating the DCV (10).
14. The system of claim 13, wherein the critical steering angle sensor (23) comprises a lever (37) that is pivotally connected with the first drop arm (39a) or the second drop arm (39b) of the steering mechanism (34).
15. The system of claims 13 to 14, wherein at least one of the drop arms (39a, 39b) oscillates the lever (37) of the critical steering angle sensor (23) with respect to the

movement of steering mechanism (34) such that when the lever (37) reaches the desired steering angle (8) during sever turn, the critical steering angle sensor (23) controls the operation of said DVC (10), which controls air pressure in the ride air springs (6) in order to partially or fully deflate the ride air springs (6) based on the steering angle of the
vehicle.
16. The system of claims 13 to 15, wherein the desired steering angle (8) of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
17. An electrical control automatic traction assistance system (lie) being operated by a steering mechanism (34) based on a steering angle of a vehicle having twin steer axles and a lift axle (1) that is arranged with a pair of ride air springs (6) and a pair of lift air springs (7), comprising:
a direction control valve (DVC, 10) pneumatically connected with a lift axle control valve (14) and the ride air springs (6) of the lift axle (1) through a quick release valve (18) to fully deflate the ride air springs (6) when the vehicle reaches a desired steering angle (8) during sever turn;
a steering sensor (41) attached to a steering wheel (42) of the vehicle to determine angular movement of the steering wheel (42);
an electronic processing unit (40) electrically connected to the DVC (10) and the steering sensor (41) for controlling the operation of said DVC (10) based on the angular movement of the steering wheel (42) in order to deflate the ride air springs (6) or supply compressed air to the ride air springs (6); and
a traction switch (TS, 12) electrically connected to an ignition switch (21) of the vehicle and the electronic processing unit (40) for activating and deactivating the DCV (10) and the electronic processing unit (40).

18. The system of claim 17, wherein the electronic processing unit (40) is operated with respect to the angular movement of the steering wheel (42) such that when the vehicle reaches the desired steering angle (8) during sever turn, the electronic processing unit (40) converts electronic pulses from the steering sensor (41) into electrical signals for controlling the operation of said DCV (10) to fully deflate the ride air springs (6).
19. The system of claims 17 and 18, wherein the desired steering angle (8) of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.
20. An electrical control automatic traction assistance system (lid) being operated by a steering mechanism (34) based on a steering angle of a vehicle having twin steer axles and a lift axle (1) that is arranged with a pair of ride air springs (6) and a pair of lift air springs (7), comprising:
a direction control valve (DVC, 10) pneumatically connected with a lift axle control valve (14) and the ride air springs (6) of the lift axle (1) through a quick release valve (18) to deflate the ride air springs (6) when the vehicle reaches a desired steering angle (8) during sever turn;
a pressure limiting valve (27) for limiting air pressure in the ride air springs (6) for partial deflation of the ride air springs (6) while deflating the ride air springs during sever turn;
an auxiliary quick release valve (31) pneumatically connected between the pressure limiting valve (27) and the DCV (10) to exhaust the compressed air from an exhaust line extended from the DCV (10);
a steering sensor (41) attached to a steering wheel (42) of the vehicle to determine angular movement of the steering wheel (42);
an electronic processing unit (40) electrically connected to the DVC (10) and the steering sensor (41) for controlling the operation of said DVC (10) based on the angular

movement of the steering wheel (42) in order to fully or partially deflate the ride air springs (6) or supply compressed air to the ride air springs (6); and
a traction switch (TS, 12) electrically connected to an ignition switch (21) of the vehicle and the electronic processing unit (40) for activating and deactivating the DCV (10) and the electronic processing unit (40).
21. The system of claim 20, wherein the electronic processing unit (40) is operated with respect to the angular movement of the steering wheel (42) such that when the vehicle reaches the desired steering angle (8) during sever turn, the electronic processing unit (40) converts electronic pulses from the steering sensor (41) into electrical signals for controlling the operation of said DCV (10) to fully or partially deflate the ride air springs (6).
22. The system of claims 20 and 21, wherein the desired steering angle (8) of the vehicle is preset within a maximum steering angle of a vehicle wheel at its steered direction.