FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
AND
The Patents Rules, 2003
COMPLETE SPECIFICATION
[See Section 10 and Rule 13]
TITLE OF THE INVENTION
A SYSTEM FOR PAYLOAD MEASUREMENT AND LOGGING THE SAME FOR THE VEHICLE
APPLICANT
TATA MOTORS LIMITED
an Indian company
having its registered office at Bombay house,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001, Maharashtra, India.
INVENTORS SANTOSH SHANKARRAO GOSAVI AND AMOL RAMESH THAKUR
Both are Indian National of
Tata Motors Limited, Bombay house,
24 Homi Mody Street, Hutatma Chowk,
Mumbai 400 001, Maharashtra, India.
PREAMBLE OF THE INVENTION
The following specification particularly describes the invention and the manner in which it is to be performed.

TECHNICAL FIELD OF THE INVENTION
[0001] The present invention generally relates to a vehicle payload measuring and logging system. More particularly, the present invention relates to an onboard vehicle payload measuring and logging system to determine a gross vehicle weight (GVW) and payload based on an axle movement.
BACKGROUND OF THE INVENTION
[0002] In commercial vehicles a trip cost is decided by payload and distance travelled. Conventionally, odometer is used for providing the trip distance; however for measuring the load a driver has to depend on an external weighting system installed at some locations. Such external weighting systems are frequently unavailable when the vehicle is loaded. Many times traffic police officers harass the driver of the truck or any other such loading vehicle and makes false claim of excess payload or overload and charge for hefty fines. Otherwise truck drivers have to prove to the officer with the proof of a dated weighbridge slip. Generally, a vehicle loading pattern is analyzed to study a warranty claim and vehicle usage condition by a vehicle manufacturer. This will help to decide whether the vehicle is used as per recommendations or a case of abuse and accordingly warranty claims can be settled.
[0003] Majority of prior art systems for measuring the vehicle payload utilize a weighting system that is integrated onto the vehicle without requiring the external weighing system. Such prior art systems includes sensor assemblies that are seamlessly installed on a chassis of the vehicle with an interface given on the driver’s cab. Such prior art payload measurement system may adversely affect the normal operation of the vehicle which may lead to inaccuracies in payload measurements and causes additional maintenance cost and extra wear on the truck tires. Additionally, such systems may not able to

provide a vehicle loading history and does not warn the driver for vehicle overloading and thereby decreases service life of the vehicle.
[0004] Hence, it is believed that a solution to these problems involves the implementation of an onboard vehicle payload measuring and logging system that is pneumatically connected to a vehicle brake circuit to determine a gross vehicle weight (GVW) and payload using an axle movement, as described in greater detail herein.
SUMMARY OF THE INVENTION
[0005] The following summary is provided to facilitate an understanding of some of the innovative features unique to the disclosed embodiments and is not intended to be a full description. A full appreciation of the various aspects of the embodiments disclosed herein can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
[0006] It is, therefore, one aspect of the present invention to provide an improved onboard vehicle payload measuring and logging system that is pneumatically connected to a vehicle brake circuit to determine a gross vehicle weight (GVW) and payload using an axle movement.
[0007] It is another aspect of the present invention to provide an onboard vehicle payload measuring and logging system having auto load sensing valves and/or load detection valves connected to the vehicle brake circuit for measurement of the gross vehicle weight and payload.
[0008] It is further aspect of the present invention to provide an onboard vehicle payload measuring and logging system, which is capable of displaying the gross vehicle weight and payload to a driver.

[0009] It is yet another aspect of the present invention to provide an onboard vehicle payload measuring and logging system, which is capable of recording a vehicle payload loading history along with a distance travelled as per date and time so as to aid the driver in calculating a trip cost.
[0010] It is further aspect of the present invention to provide an onboard vehicle payload measuring and logging system, which is capable of warning the driver for vehicle overloading to improve a service life of the vehicle by reducing / avoiding the overloading of the vehicle.
[0011] In accordance with a first embodiment of the present invention, the onboard vehicle payload measuring and logging system includes a front auto load sensing and a rear auto load sensing valve (ALSV) fitted on a chassis of a vehicle is mechanically connected to a front and rear axle via a lever in such a way to receive a pressure input from an auxiliary air tank. A solenoid valve pneumatically connected to an inlet of the front ALSV is supplied with air from the auxiliary air tank and a double check valve pneumatically connected to an inlet of the rear ALSV is supplied with air via the solenoid valve and a dual brake valve and passes only higher inlet pressure to the rear ALSV.
[0012] A switch serially connected between a relay and the solenoid valve is fitted on a dash board of the vehicle to activate or deactivate the solenoid valve based on a vehicle static/ dynamic condition signal received from an engine management unit and to control the air pressure input to the front and rear ALSV and the double check valve. A front axle pressure sensor and a rear axle pressure sensor connected with the front and rear ALSV senses a front and rear pressure output from the front and rear ALSV based on a payload of the vehicle. An amplifier controller receives a front and rear pressure signal from the front axle and rear axle pressure sensor to determine a gross vehicle weight and payload based on a front axle weight and a rear axle weight and displays the gross vehicle weight and payload to a display unit.

[0013] The auxiliary air tank is pneumatically connected to a rear spring brake actuator through a hand brake valve in such a way that the hand brake valve on actuation closes the auxiliary air tank delivery to the spring brake actuator and exhausts the pressure in the spring brake actuator parking side to atmosphere. The dual brake valve input is pneumatically connected to a front service tank and a rear service tank and an output is connected to a front brake chamber and the rear ALSV through the double check valve. The dual brake valve modulates the service tank pressure and supplies to the front brake chamber and the rear brake actuator, on driver’s application of a brake pedal and the air pressure supply to the rear spring brake actuator is routed through the rear ASLV for further modulation as per the vehicle loading condition.
[0014] The solenoid valve blocks the air pressure input signal to the dual check valve and the front and rear ALSV if the relay is in off condition. The switch is operated to initiate the payload measurement and display the payload and the gross vehicle weight on the display unit. The solenoid valve connects the auxiliary air tank pressure to the front ALSV and the double check valve if the relay is in on condition so that the auxiliary air tank pressure is supplied to the rear ALSV and based on the payload on the vehicle both the front and rear ALSV provides the pressure output signal. The front and rear ALSV receives a constant pressure input from the auxiliary air tank and a delivery pressure of the front and rear ALSV varies with respect to the lever angle that changes with respect to the vehicle loading condition. A tank pressure sensor is electrically connected to the auxiliary air tank to sense a pressure signal from the auxiliary air tank which is fed to the amplifier controller. The amplifier controller based on the signal from front axle and rear axle pressure sensor and the tank pressure sensor calculates the front axle weight and rear axle weight using a calibration curve. The gross vehicle weight is determined by the front and rear axle weight and the payload is determined by a vehicle kerb weight and the gross vehicle weight.
[0015] In accordance with an exemplary second embodiment of the present invention, the onboard vehicle payload measuring and logging system that

is pneumatically connected to a vehicle brake circuit includes two separate load detection valves (LDV) that is fitted at a front and rear axle instead of the auto load sensing valves (ALSV). Front and rear LDV are similar to the ALSV, only difference is that, the delivery pressure depends only on the lever angle instead on the inlet pressure. A separate rear ALSV can also be included in the rear brake circuit. The front and rear LDV are fitted on a chassis of a vehicle and is mechanically connected to a front and rear axle via a lever. A mechanically operated hand brake valve is connected to an auxiliary air tank in such a way that air flows from the auxiliary air tank to an inlet of the front and rear LDV upon actuation of the hand brake valve. A front axle pressure sensor and a rear axle pressure sensor is electrically connected with the front and rear LDV senses a front and rear pressure output from the front and rear LDV based on a payload of the vehicle. An amplifier controller receives a front and rear pressure signal from the front axle and rear axle pressure sensor to determine a gross vehicle weight and payload based on a front axle weight and a rear axle weight and displays the gross vehicle weight and payload to a display unit.
[0016] The rear auto load sensing valve can also be fitted on the chassis of the vehicle and a lever of the rear ALSV is mechanically connected to the rear axle in such a way to receive the pressure input from the auxiliary air tank via a dual brake valve. The front and rear LDV provides the delivery pressure based on the load in the vehicle that depends on the lever angle. The hand brake valve is operated manually to initiate the payload measurement and display the payload and the gross vehicle weight on the display unit. The gross vehicle weight is determined by the front and rear axle weight via a calibration curve and the payload is determined by a vehicle kerb weight and the gross vehicle weight. The amplifier controller compares a current payload with a previous payload to monitor and record the current payload data along with an odometer reading, date and time.

[0017] In accordance with an exemplary third embodiment of the present invention, the onboard vehicle payload measuring and logging system, is controlled electronically through an amplifier controller. The system includes a solenoid valve electrically connected to the amplifier controller via an electronic relay in such a way that the electronic relay activates the solenoid valve upon receiving a signal from the amplifier controller with respect to an engine start condition from an engine management unit. A front axle load detection valve (LDV) and a rear axle load detection valve fitted on a chassis of a vehicle is mechanically connected to a front and rear axle via a lever in such a way that air flows from an auxiliary air tank to inlet of the front and rear LDV once the solenoid valve gets activated. A separate front and rear ALSV can also be included in the brake circuit. A front axle pressure sensor and a rear axle pressure sensor is electrically connected with the front and rear LDV senses a front and rear pressure output from the front and rear LDV based on a payload of the vehicle. An amplifier controller receives a front and rear pressure signal from the front axle and rear axle pressure sensor to determine a gross vehicle weight and payload based on a front axle weight and a rear axle weight and displays the gross vehicle weight and payload to a display unit.
[0018] The front and rear LDV receives air from an auxiliary air tank upon activation of the solenoid valve and the front and rear LDV give the delivery pressure according to the load in the vehicle. The gross vehicle weight is determined by the front and rear axle weight via a calibration curve and the payload is determined by a vehicle kerb weight and the gross vehicle weight. The hand brake valve is operated manually to initiate the payload measurement and display the payload and the gross vehicle weight on the display unit. The amplifier controller compares a current payload with a previous payload to monitor and record the current payload data along with an odometer reading, date and time. The amplifier controller automatically transmits another trigger signal to the electronic relay after the time period to switch off the solenoid valve so that the system is switched off to reduce air consumption. The engine is switched off

during the vehicle loading or unloading and each change from loading to unloading or vice-versa is recorded into the system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The disclosed embodiments may be better understood by referring to the figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views, further illustrate the present invention and, together with the detailed description of the invention, serve to explain the principles of the present invention.
[0020] FIG. 1 illustrates a schematic representation of an onboard vehicle payload measuring and logging system that is pneumatically connected to a vehicle brake circuit via auto load sensing valves, in accordance with an exemplary first embodiment of the present invention;
[0021] FIG.2 illustrates a flow chart of operations for measuring payload and gross vehicle weight, in accordance with the exemplary first embodiment of the present invention;
[0022] FIG.3 illustrates a schematic representation of an onboard vehicle payload measuring and logging system that is pneumatically connected to a vehicle brake circuit via load detection valves, in accordance with an exemplary second embodiment of the present invention;
[0023] FIG. 4 illustrates a schematic representation of the onboard vehicle payload measuring and logging system that is pneumatically connected to a vehicle brake circuit via a rear auto load sensing valve and the load detection valves, in accordance with the exemplary second embodiment of the present invention;

[0024] FIG. 5 illustrates a flow chart of operations for measuring payload and gross vehicle weight, in accordance with the exemplary second embodiment of the present invention;
[0025] FIG. 6 illustrates a schematic representation of an onboard vehicle payload measuring and logging system that is controlled electronically through an amplifier controller, in accordance with an exemplary third embodiment of the present invention;
[0026] FIG. 7 illustrates a characteristic curve of axle weight versus pressure sensor output voltage, in accordance with all exemplary embodiments of the present invention; and
[0027] FIG. 8 illustrates a flow chart of operations for measuring payload and gross vehicle weight, in accordance with the exemplary third embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0028] The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
[0029] In the following, numerous specific details are set forth to provide a thorough description of various embodiments. Certain embodiments may be practiced without these specific details or with some variations in detail. In some instances, certain features are described in less detail so as not to obscure other aspects. The level of detail associated with each of the elements or features should not be construed to qualify the novelty or importance of one feature over the others.

[0030] The claimed subject matter has been provided here with reference to one or more features or embodiments. Those skilled in the art will recognize and appreciate that, despite of the detailed nature of the exemplary embodiments provided here; changes and modifications may be applied to said embodiments without limiting or departing from the generally intended scope. These and various other adaptations and combinations of the embodiments provided here are within the scope of the disclosed subject matter as defined by the claims and their full set of equivalents. Like numbers refer to like elements throughout.
[0031] The present invention is an onboard vehicle payload measuring and logging system that is pneumatically connected to a vehicle brake circuit to determine a gross vehicle weight (GVW) and payload using an axle movement. The system includes an auto load sensing valve or a load detection valve connected to the vehicle brake circuit for measurement of the gross vehicle weight and payload. The payload measurement is initiated via a switch or a hand brake valve or electronically controlled via a relay so that the valves provide a delivery pressure based on the load in the vehicle that depends on the lever angle.
[0032] The system is capable of displaying the gross vehicle weight and payload to a driver and recording a vehicle payload loading history along with a distance travelled as per calendar and time so as to aid the driver in calculating the trip cost. The system also warns the driver for vehicle overloading to improve the service life of vehicle by reducing / avoiding overloading of vehicle. The system also facilitates a hassle free driving on trip. The driver need not to have fear of RTO and traffic police officers for showing loading condition and weight receipt for the vehicle. The system track record of vehicle usage in terms of payload carried by the vehicle with the distance information with no adverse effect on the normal braking system.
[0033] Referring to FIG. 1 a schematic representation of an onboard vehicle payload measuring and logging system (25) that is pneumatically

connected to a vehicle brake circuit (not shown) via auto load sensing valves (2, 3) is illustrated, in accordance with an exemplary first embodiment of the present invention. Note that in FIGS. 1-8 identical parts or elements are generally indicated by identical reference numerals. The onboard vehicle payload measuring and logging system (25) includes a front auto load sensing valve (ALSV, 2) fitted on a front axle (not shown) and a rear auto load sensing valve (ALSV, 3) fitted on the rear axle (not shown). The front and rear ALSV (2, 3) are fixed on a chassis member and its linkage is fixed on the axle. Since the change in vehicle loading alters the chassis height, the ALSV linkage moves relative to the front and rear ALSV (2, 3) and modulate the delivery pressure. The front and rear ALSV (2, 3) is used to detect the loading condition of the vehicle. The front and rear ALSV (2, 3) have a constant pressure input from a parking tank or an auxiliary air tank (1). The parking tank is hereafter referred as auxiliary air tank (1) only for the purpose of explanation, but not by the way of any limitations.
[0034] An inlet of the front ALSV (2) is connected to a delivery of a solenoid valve (7) and an inlet of the rear ALSV (3) is connected to a delivery of a double check valve (13). The double check valve (13) has two inlets, one from the solenoid valve (7) and another from rear delivery of a dual brake valve (14). The double check valve (13) passes only one inlet pressure, whichever is the higher, to the delivery. The inlet of the solenoid valve (7) is supplied with air from the auxiliary air tank (1). An ON/OFF switch (8) is electrically connected in serial between a relay (12) and the solenoid valve (7) is fitted on the dash board of the vehicle. The electronic relay (12) receives a signal from an engine management ECU (9) regarding a vehicle static/ dynamic condition. The electronic relay (12) is fitted in the series with the ON/OFF switch (8) to avoid the sudden actuation of the payload detection system (25) which may result in sudden application of rear brakes of vehicle and which in turn may result in an accident in dynamic condition.

[0035] Generally, the vehicle brake system has two service air tanks (18), i.e. (a) front service air tank and (b) rear service air tank, and the auxiliary air tank (1). Compressed air is supplied to these tanks (18) from the air compressor mounted on the engine. The two service air tanks (18) are provided for brake, i.e. one is for front brake and another is for rear brake. These tanks are pneumatically connected to the dual brake valve (14). The dual brake valve (14) has two inlets, from the service air tanks (18), and two delivery lines. One delivery line is connected to a front brake chamber (16) and rear brake line is connected to the rear ALSV (3) through the double check valve (13). The delivery of rear ALSV (3) is connected to the rear spring brake actuators (17). The solenoid valve is operated by an ON/OFF switch (8) fitted in dash board, through the electronic relay (12). The electronic relay (12) gets “on” and “off” based on the engine “on” and “off” signal of Engine management system (EMS) ECU (9).
[0036] The dual brake valve (14) modulates the service tank (18) pressure and supplies to the front brake chambers (16) and a rear brake actuator (17), on drivers application of brake pedal. The air pressure supply to the rear spring brake actuator (17) is routed through the rear ALSV (3) to have further modulation as per vehicle loading condition. The auxiliary air tank (1) is pneumatically connected to the rear spring brake actuator (17) through the hand brake valve (15) mounted in driver’s cabin. The hand brake valve (15), on actuation, closes the auxiliary air tank (1) delivery to the spring brake actuator (17) and exhaust the pressure in spring brake actuator (17) parking side to the atmosphere. The pressure output from the rear load sensing valve (3) is tapped and measured to determine the payload on vehicle.
[0037] An air pressure sensor (6) is fitted on the auxiliary air tank (1), to sense the tank pressure. The delivery pressure of the front and rear ALSV (2, 3) varies with respect to the lever angle. The lever angle changes with respect to the chassis height i.e. vehicle loading condition. A front axle pressure sensor (4) is fitted in the delivery of the front auto load sensing valve (2) and a rear axle pressure sensor (5) fitted into the delivery of the rear auto load sensing valve (3).

The pressure signal from the front axle and rear axle pressure sensor (4, 5) is transmitted to an amplifier controller (10). The amplifier controller (10) also receives a pressure signal from the pressure sensor (6) fitted on the auxiliary air tank (1).
[0038] When the ON/OFF switch (8) is in OFF condition, there will be no supply of air pressure to the front and rear ALSV (2, 3) hence there will be no delivery pressure and no pressure signal from the front and rear axle pressure sensor (4, 5) to the amplifier controller (10). On application of brake pedal of the dual brake valve (14), the air is supplied to the inlet of the rear auto load sensing valve (3) from the double check valve (13) delivery and further to a rear spring brake actuator (17). The front and rear pressure signal is fed to the amplifier controller (10), also pressure signal form the tank pressure sensor (6) is also feed to the amplifier controller (10). The amplifier controller (10) process the signals and gives the output signal to an instrument cluster / display unit (11) which displays the payload / gross vehicle weight. The instrument cluster is hereafter referred as display unit (11) only for the purpose of explanation, but not by the way of any limitations. The amplifier controller (10) process these signal and, based on axle load versus pressure output calibration curve (75) as shown in FIG. 7, and provides output signal to the display unit (11). Accordingly, the display unit (11) can display the payload and gross vehicle weight.
[0039] FIG. 2 illustrates a flow chart (30) of operations for measuring payload and gross vehicle weight, in accordance with the exemplary first embodiment of the present invention. Referring to FIGS. 1-2, during normal operation, when brake pedal of the dual brake valve (14) is applied, the air pressure from the service air tanks (18) is supplied to the front brake chambers (16) and the rear brake actuator (17). The pressure to the rear spring brake actuator (17) is passed through the double check valve (13). Since during the normal operation, the ON/OFF switch (8) is in off condition, there is no pressure supply to the other inlet port of the double check valve (13). The air from

delivery of the double check valve (13) is further modulated in the rear auto load sensing valve (3) and goes to the rear spring brake actuator (17).
[0040] Whenever, the driver needs to know the gross vehicle weight or payload in the vehicle, the vehicle must be in the stationary condition according to an embodiment of the present invention. Further, the driver has to press the ON/OFF switch (8) on dash board, based on the engine “ON’ and “OFF” signal from the EMS ECU (9) and the electronic relay (12) will be in on or off condition. When engine is firing the electronic relay (12) is off and the solenoid valve (7) provides air pressure input to the dual check valve (13) and front and rear axle auto load sensing valve (2, 3). If the electronic relay (12) is in on condition, the solenoid valve (7) is in “ON” condition and connects the auxiliary air tank (1) pressure to the front axle auto load sensing valve (2) and the double check valve (13). Since during this operation, there is no brake application, the parking/auxiliary air tank (1) pressure is supplied to the rear auto load sensing valve (3).
[0041] As the front and rear ALSV (2, 3) has its lever connected to the axle, based on the payload on vehicle both the auto load sensing valve (2, 3) gives the pressure output. This pressure output is sensed by the front axle and rear axle pressure sensor (4, 5), as shown at blocks (31, 32). This pressure signal is transmitted to the amplifier controller (10). Also the signal from the pressure sensor (6) mounted on the auxiliary air tank (1) is supplied to the amplifier controller (10), as depicted at block (33). The amplifier controller (10) based on the signal from the front axle and rear axle pressure sensor (4, 5) and the tank pressure sensor (6) calculates the front axle weight and rear axle weight using respective calibration curve (75) of axle weight versus auto load sensing valve pressure sensor output voltage, as shown in FIG. 7. The gross vehicle weight is calculated by adding the front and rear axle weights, as illustrated at block (34). Vehicle kerb weight (unladden weight) which is a design specification may be fixed or constant value for a vehicle type and is flashed in the amplifier controller

(10). The payload is calculated by subtracting the vehicle kerb weight from the measured gross vehicle weight as shown below in equation (1):
Gross vehicle weight = (Front axle weight) + (Rear axle weight)
Vehicle payload = Gross vehicle weight – Vehicle kerb weight,
Vehicle payload = [(Front axle weight) + (Rear axle weight)]–Vehicle kerb
weight (1)
[0042] The measured gross vehicle weight and the payload is displayed on the vehicle display unit (11), as shown at block (35). Once the driver switch off the ON/OFF switch (8), the pressure from the front axle and rear axle ALSV (2, 3) is exhausted into the atmosphere from the exhaust of the solenoid valve (7). Hence there is no pressure signal output from the front axle and rear axle pressure sensor (4, 5) to the amplifier controller (10). Accordingly there is no payload/GVW display on the display unit (11).
[0043] Referring to FIG.3 a schematic representation of an onboard vehicle payload measuring and logging system (40) that is pneumatically connected to a vehicle brake circuit via load detection valves (19, 20) is illustrated, in accordance with an exemplary second embodiment of the present invention. Similar reference numerals for same components or parts are being marked and referred in all the embodiments of the present invention only for the purpose of easy understanding of the invention, but it is not by the way of any limitations. The system (40) includes a front axle load detection valve (LDV, 19) and a rear axle load detection valve (LDV, 20) fitted on a chassis of the vehicle and a lever of the front and rear LDV (19, 20) is mechanically connected to a front and rear axle respectively. The front and rear LDV (19, 20) are similar to the front axle and rear axle ALSV (2, 3), only difference is that, the delivery pressure depends on the lever angle instead of the inlet pressure.

[0044] A mechanically operated hand brake valve (21) is connected to the auxiliary air tank (1) in such a way that air flows from the auxiliary air tank (1) to an inlet of the front LDV (19) and the rear LDV (20) upon actuation of the hand brake valve (21). A front axle pressure sensor (4) and a rear axle pressure sensor (5) is electrically connected with the front LDV (19) and the rear LDV (20) to sense a front and rear pressure output from the front and rear LDV (19, 20) based on a payload of the vehicle. An amplifier controller (10) receives a front and rear pressure signal to determine a front axle weight and a rear axle weight using the calibration curve (75), as shown in FIG. 7, and transmit a gross vehicle weight output signal to the display unit (11). As the on-board load detection system (40) is independent of the vehicle brake system, sudden actuation of the payload detection system (40) does not affect the normal functioning of the vehicle.
[0045] FIG. 4 illustrates a schematic representation of an onboard vehicle payload measuring and logging system (50) that is pneumatically connected to the vehicle brake circuit via the rear auto load sensing valve (ALSV, 3) and the load detection valves (19, 20), in accordance with the exemplary second embodiment of the present invention. As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention.
[0046] The onboard vehicle payload measuring and logging system (50) includes the auto load sensing valve (3) in rear brake circuit. The load detection valves (19, 20) are also fitted at front and rear axle, without disturbing the vehicle braking circuit. The front and rear load detection valves (19, 20) are similar to the auto load sensing valve (3), only difference is that, its delivery pressure is only

depends on the lever angle instead of the inlet pressure. The mechanically operated hand brake valve (21) is connected to the auxiliary air tank (1) in such a way that air flows from the auxiliary air tank (1) to the inlet of the front LDV (19) and the rear LDV (20) upon actuation of the hand brake valve (21). The front axle pressure sensor (4) and the rear axle pressure sensor (5) is electrically connected with the front LDV (19) and the rear LDV (20) senses a front and rear pressure output from the front and rear LDV (19, 20) based on a payload of the vehicle. The amplifier controller (10) receives a front and rear pressure signal to determine a front axle weight and a rear axle weight using the calibration curve (75), as shown in FIG. 7, and transmit a gross vehicle weight output signal to the display unit (11). As the on-board payload measuring and logging system (50) is independent of the vehicle brake system, sudden actuation of payload detection system does not affect the normal functioning of the vehicle.
[0047] FIG. 5 illustrates a flow chart (60) of operations for measuring payload and gross vehicle weight, in accordance with second of the present invention. The additional hand brake valve (21) is operated whenever a driver wants to check the payload/ GVW or want to log the payload/GVW data. The front and rear LDV (19, 20) is used for load detection. On actuation of the hand brake valve (21) the air flows from the auxiliary air tank (1) to inlet of the rear load detection valve (20) and front load detection valve (19). According to the load in the vehicle, the front and rear load detection valve (19, 20) gives the delivery pressure. This delivery pressure from the front load detection valve (19) is sensed by the front axle pressure sensor (4) and the delivery pressure from the rear load detection valve (20) is sensed by the rear axle pressure sensor (5), as shown at blocks (61) and (62). The pressure values from the front axle and rear axle pressure sensor (4, 5) is fed to the amplifier controller (10), where it processes the values as per predefined program, as shown at block (63).
[0048] The amplifier controller (10) based on the signal from the front axle and rear axle pressure sensor (4, 5) calculates the front axle weight and rear

axle weight using respective calibration curve (75) of axle weight versus pressure sensor output voltage, as shown in FIG. 7. The gross vehicle weight is calculated by adding the front and rear axle weights. Vehicle kerb weight (unladden weight) which is a design specification may be fixed or constant value for a vehicle type and is flashed in the amplifier controller (10). The payload is calculated by subtracting the vehicle kerb weight from the measured gross vehicle weight as shown below in equation (1):
Gross vehicle weight = (Front axle weight) + (Rear axle weight)
Vehicle payload = Gross vehicle weight – Vehicle kerb weight,
Vehicle payload = [(Front axle weight) + (Rear axle weight)]–Vehicle kerb
weight (1)
[0049] The current payload is compared with the previous payload, as indicated at block (64). If the current payload is equal to the previous payload the GVW/payload is displayed on the display unit (11), as shown at block (65). If the current payload is not equal to the previous payload the current payload is recorded in the logger with date, odometer reading and time and the trip distance, payload and time is calculated, as shown at blocks (66) and (67).
[0050] Referring to FIG. 6 a schematic representation of an onboard vehicle payload measuring and logging system (70) that is controlled electronically through an amplifier controller (10) is illustrated, in accordance with an exemplary third embodiment of the present invention. The system (70) includes a solenoid valve (7) that is electrically connected to the amplifier controller (10) via an electronic relay (12) in such a way that the electronic relay (12) activates the solenoid valve (7) upon receiving a signal from the amplifier controller (10) with respect to an engine start condition from an engine management system ECU (9). The solenoid valve (7) is used to actuate the payload measuring and logging system (70). The solenoid valve (7) is controlled

by the amplifier controller (10), through the electronic relay (12), which gets input from the engine management system ECU (9).
[0051] The system (70) further includes a front axle load detection valve (LDV, 19) and a rear axle load detection valve (LDV, 20) that is fitted on the chassis of the vehicle and a lever of the front and rear LDV (19, 20) is mechanically connected to a front and rear axle in such a way that air flows from an auxiliary air tank (1) to inlet of the front and rear LDV (19, 20) once the solenoid valve (7) gets activated. A front axle pressure sensor (4) and a rear axle pressure sensor (5) that is electrically connected with the front LDV (19) and the rear LDV (20) senses a front and rear pressure output from the front and rear LDV (19, 20) based on a payload of the vehicle.
[0052] The amplifier controller (10) receives a front and rear pressure signal to determine a front axle weight and a rear axle weight using a calibration curve and transmit a gross vehicle weight output signal to a display unit (11). A logic is built in the controller (10) such that on every event of engine start, a signal goes to the solenoid valve (7) and the system (70) gets activate and records the instantaneous reading of the GVW/payload along with date, time and an odometer reading. After recording the above data, the system (70) automatically goes OFF after a certain time interval, for example 10 minutes. The system (70) assists in removing the manual actuation / driver dependency of the system (70) as well as reduces the air consumption of the system (70). In a preferred embodiment, the system (70) may also include the front and rear ALSV (2, 3).
[0053] Referring to FIG. 8 a flow chart (80) of operations for measuring the payload and gross vehicle weight is illustrated, in accordance with the exemplary third embodiment of the present invention. Similar reference numerals for same components or parts are being marked and referred in all the embodiments of the present invention only for the purpose of easy understanding of the invention, but it is not by the way of any limitations. The activation of the onboard vehicle payload measuring and logging system (70) is controlled

electronically through the amplifier controller (10). The amplifier controller (10) receives the signal from the engine management system (EMS) ECU (9) that the engine is being started, as shown at blocks (81) and (82). The amplifier controller (10) transmits the signal to the electronic relay (12) to activate the solenoid valve (7) if the engine is in ON condition, as shown at block (83). Once the solenoid valve (7) gets activated, the air flows from the auxiliary air tank (1) to inlet of the rear load detection valve (20) and front load detection valve (19).
[0054] According to the load in the vehicle, the front and rear LDV (19, 20) give the delivery pressure, as depicted at blocks (84) and (85). The delivery pressure from the front LDV (19) is sensed by the front axle pressure sensor (4) and the delivery pressure from the rear LDV (20) is sensed by the rear axle pressure sensor (5). The pressure values from the front axle and rear axle pressure sensors (4, 5) is fed to the amplifier controller (10), where it process those values as per predefined program and display the GVW/Payload on the display unit (11), as indicated at block (86). The amplifier controller (10) based on the signal from the front axle and rear axle pressure sensor (4, 5) calculates the front axle weight and rear axle weight using respective calibration curve (75) of axle weight versus pressure sensor output voltage, as shown in FIG. 7. The gross vehicle weight is calculated by adding the front and rear axle weights. Vehicle kerb weight (unladden weight) which is a design specification may be fixed or constant value for a vehicle type and is flashed in the amplifier controller (10). The payload is calculated by subtracting the vehicle kerb weight from the measured gross vehicle weight as shown below in equation (1):
Gross vehicle weight = (Front axle weight) + (Rear axle weight)
Vehicle payload = Gross vehicle weight – Vehicle kerb weight,
Vehicle payload = [(Front axle weight) + (Rear axle weight)]–Vehicle kerb
weight (1)

[0055] The current payload is compared with the previous payload, as indicated at blocks (87) and (88). If the current payload is not equal to the previous payload the current payload is recorded in the logger and the trip distance, payload and time is calculated, as shown at blocks (89) and (91). At the same time the amplifier controller (10) monitors and records the GVW/payload data at that instant, along with the odometer reading, date and time, as shown at block (92). Once the data is recorded, the amplifier controller (10) monitor the same for certain time period for example 10 min and then give another trigger signal to the electronic relay (12) to switch off the solenoid valve (7) and thus the vehicle payload measuring and logging system (70) is switched off, as indicated at blocks (93) and (94). The vehicle payload measuring and logging system (70) is not actuated till there is another engine OFF and ON cycle, as indicated at block (95). Generally during the vehicle loading or unloading the engine is switched off and hence each change from loading to unloading or vice-versa is recorded into the system (70). Once the payload/GVW data is recorded into the system (70), the amplifier controller (10) automatically switches off the solenoid valve (7) after certain amount of time e.g. 10 minutes to reduce the air consumption by the system (70).
[0056] It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.

WE CLAIM:
1. An onboard vehicle payload measuring and logging system (25) that is
pneumatically connected to a vehicle brake circuit, comprising:
a front auto load sensing valve (ALSV, 2) and a rear auto load sensing valve (ALSV, 3) fitted on a chassis of a vehicle is mechanically connected to a front and rear axle via a lever in such a way to receive a pressure input from an auxiliary air tank (1);
a solenoid valve (7) pneumatically connected to an inlet of the front ALSV (2) is supplied with air from the auxiliary air tank (1) and a double check valve (13) pneumatically connected to an inlet of the rear ALSV (3) is supplied with air via the solenoid valve (7) and a dual brake valve (14);
a switch (8) serially connected between a relay (12) and the solenoid valve (7) is fitted on a dash board of the vehicle to activate or deactivate the solenoid valve (7) based on a vehicle static/ dynamic condition signal received from an engine management unit (9) and to control the air pressure input to the front and rear ALSV (2, 3);
a front axle pressure sensor (4) and a rear axle pressure sensor (5) connected with the front and rear ALSV (2, 3) senses a front and rear pressure output from the front and rear ALSV (2, 3) based on a payload of the vehicle; and
an amplifier controller (10) receives a front and rear pressure signal from the front axle and rear axle pressure sensor (4, 5) to determine a gross vehicle weight and payload based on a front axle weight and a rear axle weight and displays the gross vehicle weight and payload to a display unit (11).
2. The system of claim 1, wherein the auxiliary air tank (1) is
pneumatically connected to a rear spring brake actuator (17) via a hand brake
valve (15) in such a way that the hand brake valve (15) on actuation closes the
auxiliary air tank (1) delivery to the spring brake actuator (17) and exhaust the
pressure in the spring brake actuator (17) parking side to atmosphere.

3. The system of claim 1, wherein the dual brake valve (14) input is pneumatically connected to a front service tank (18a) and a rear service tank (18b), and an output is connected to a front brake chamber (16) and the rear ALSV (3) through the double check valve (13).
4. The system of claim 1 and 3, wherein the dual brake valve (14) modulates the service tank (18) pressure and supplies to the front brake chamber (16) and the rear brake actuator (17), on drivers application of a brake pedal and an air pressure supply to the rear spring brake actuator (17) is routed via the rear ASLV (3) for further modulation as per the vehicle loading condition.
5. The system of claim 1, wherein the solenoid valve (7) blocks the air pressure input signal to the dual check valve (13) and the front and rear ALSV (2, 3) if the relay (12) is in off condition.
6. The system of claim 17, wherein the switch (8) is operated to initiate the payload measurement and display the payload and the gross vehicle weight on the display unit (11).
7. The system of claim 1, wherein the solenoid valve (7) connects the auxiliary air tank (1) pressure to the front ALSV (2) and the double check valve (13) if the relay (12) is in on condition so that the auxiliary air tank (1) pressure is supplied to the rear ALSV (3) and based on the payload on the vehicle both the front and rear ALSV (2, 3) provides the pressure output signal.

8. The system of claim 1, wherein the front and rear ALSV (2, 3) receives a constant pressure input from the auxiliary air tank (1) and a delivery pressure of the front and rear ALSV (2, 3) varies with respect to the lever angle that changes with respect to the vehicle loading condition.
9. The system of claim 1, further comprising a tank pressure sensor (6) is electrically connected to the auxiliary air tank (1) to sense a pressure signal from the auxiliary air tank (1) which is fed to the amplifier controller (10).
10. The system of claims 1 and 8, wherein the amplifier controller (10) based on the signal from front axle and rear axle pressure sensor (4, 5) and the tank pressure sensor (6) calculates the front axle weight and rear axle weight using a calibration curve.
11. The system of claims 1, 8 and 9, wherein the gross vehicle weight is determined by the front and rear axle weight and the payload is determined by a vehicle kerb weight and the gross vehicle weight.
12. A payload measuring and logging system (40, 50) that is pneumatically connected to a vehicle brake circuit, comprising:
a front axle load detection valve (LDV, 19) and a rear axle load detection valve (LDV, 20) fitted on a chassis of a vehicle is mechanically connected to a front and rear axle via a lever;
a mechanically operated hand brake valve (21) is connected to an auxiliary air tank (1) in such a way that air flows from the auxiliary air tank (1) to an inlet of the front LDV (19) and the rear LDV (20) upon actuation of the hand brake valve (21);

a front axle pressure sensor (4) and a rear axle pressure sensor (5) is electrically connected with the front LDV (19) and the rear LDV (20) senses a front and rear pressure output from the front and rear LDV (19, 20) based on a payload of the vehicle; and
an amplifier controller (10) receives a front and rear pressure signal from the front axle and rear axle pressure sensor (4, 5) to determine a gross vehicle weight and payload based on a front axle weight and a rear axle weight and displays the gross vehicle weight and payload to a display unit (11).
13. The system of claim 12, further comprising a rear auto load sensing valve (ALSV, 3) is mechanically connected to the rear axle via the lever in such a way to receive the pressure input from the auxiliary air tank (1) via a dual brake valve (14).
14. The system of claim 12, wherein the front and rear load detection valve (19, 20) provides the delivery pressure based on the load in the vehicle that depends on the lever angle.
15. The system of claim 12, wherein the hand brake valve (21) is operated manually to initiate the payload measurement and display the payload and the gross vehicle weight on the display unit (11).

16. The system of claim 12 wherein the amplifier controller (10) compares a current payload with a previous payload to monitor and records the current payload data along with an odometer reading, date and time.
17. A payload measuring and logging system (70) that is pneumatically connected to a vehicle brake circuit, comprising:
a solenoid valve (7) is electrically connected to an amplifier controller (10) via an electronic relay (12) in such a way that the electronic relay activates the solenoid valve (7) upon receiving a signal from the amplifier controller (10) with respect to an engine start condition from an engine management unit (9);
a front axle load detection valve (LDV, 19) and a rear axle load detection valve (LDV, 20) fitted on a chassis of a vehicle is mechanically connected to a front and rear axle via a lever in such a way that air flows from an auxiliary air tank (1) to inlet of the front and rear LDV (19, 20) once the solenoid valve (7) gets activated;
a front axle pressure sensor (4) and a rear axle pressure sensor (5) is electrically connected with the front and rear LDV (19, 20) senses a front and rear pressure output from the front and rear LDV (19, 20) and the amplifier controller (10) determines and displays a gross vehicle weight and payload to a display unit (11).
19. The system of claim 18, further comprising a front auto load sensing valve (ALSV, 2) and a rear auto load sensing valve (ALSV, 3) mechanically connected to the front and rear axle via the lever in such a way to receive a pressure input from the auxiliary air tank (1).
20. The system of claim 18, wherein the front and rear LDV (19, 20) receives air from the auxiliary air tank (1) upon activation of the solenoid valve (7) and the front and rear LDV (19, 20) give the delivery pressure according to the load in the vehicle.

21. The system of claim 18, wherein the gross vehicle weight is determined by the front and rear axle weight via a calibration curve and the payload is determined by a vehicle kerb weight and the gross vehicle weight.
22. The system of claim 18, wherein the amplifier controller (10) compares a current payload with a previous payload to monitor and record the current payload data along with an odometer reading, date and time.
23. The system of claim 18 and 22, wherein the amplifier controller (10) automatically transmits another trigger signal to the electronic relay (12) after a time period to switch off the solenoid valve (7) so that the system is switched off to reduce air consumption.