DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
WHEEL STEERING CONTROL SYSTEM

Applicant:
BEML Limited
A company Incorporated in India under the Companies Act, 1956
Having address:
BEML Soudha, 23/1, 4th Main,
Sampangirama Nagar, Bengaluru,
Karnataka - 560 027, India

The following specification particularly describes the invention and the manner in which it is to be performed

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority from an Indian Provisional Application 202041001723 filed on 14th January 2020.
TECHNICAL FIELD
[002] The present subject matter described herein, in general, relates to a wheel steering control system for a vehicle. More particularly the wheel steering control system for the vehicle towing tractors through a sensor.
BACKGROUND
[003] A towing tractor of an air vehicle is an airfield ground vehicle, which push or pull the air vehicles. The transmission control system of towing tractor includes mechanical, electric, hydraulic and hydrodynamic transmission. The towing tractors are mainly used for pushback the air vehicle from the terminal gate after the air vehicle is loaded and ready for next take off. In addition, towing tractors are used for towing the air vehicle to a hangar for maintenance operations.
[004] The mechanical transmission was widely used in early towing tractors, but it is not suitable because of less flexibility and other shortcomings. The manually operated coupling of towing tractor with aircraft for pushing or towing operation, here the coupling is commonly a tow bar system. The tow bar system with conventional steering may leads risks of personnel injuries and towing operation accidents. The tow bar system requires larger turn radius, require more workers to operate, move at slower speeds, and have an increased set up and break down time associated while connecting the tow bar.
[005] Therefore, there is requirement of a towing system with improved efficiency, maintenance, and performance.
SUMMARY
[006] Before the present system and method are described, it is to be understood that this application is not limited to the particular machine or an apparatus, and methodologies described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular versions or embodiments only, and is not intended to limit the scope of the present application. This summary is provided to introduce aspects related to a wheel steering control system for vehicle towing tractors.The aspects are further elaborated as below in the detailed description. This summary is not intended to identify essential features of the proposed subject matter nor is it intended for use in determining or limiting the scope of the proposed subject matter.
[007] The present subject matter described herein, in general, relates to a wheel steering control system for the vehicle towing tractors through a sensor.
[008] In order to reach above-mentioned purpose of in the present invention the wheel steering control system is introduced. The system is providing four different steering modes i.e., front wheel mode, rear wheel mode, four wheel mode and crab wheel mode. In order to select the different steering modes the system provides intelligent and safety interlocks. For selection of new steering mode it is necessary to have the gear in neutral position, the parking brake is applied and wheels must be in straight ahead position. For emergency steering mode, the vehicle remains in the current mode until the wheels are in straight ahead position. The controller is switch over to front wheel steering mode once the wheels are come into straight ahead position i.e., after receipt of signals from the proximity switches. For manual override selection, when the manual override switch is ON, any steering is selectable irrespective of wheel straight-ahead condition. However, it is necessary to have the gear in neutral position and applied parking brakes. Upon detection of solenoid failure, the system enters into a default steering mode i.e., front wheel steering mode.
[009] Therefore, the wheel steering control system facilities driver to select different steering mode and provides intelligent and safety interlocks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed description of embodiments, is better understood when read in conjunction with the appended drawing. For illustrating the disclosure, there is shown in the present document example constructions of the disclosure, however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing.
[0011] The detailed description is described with reference to the accompanying figure. In the figure, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawing to refer like features and components.
[0012] Figure 1 illustrates a schematic of a wheel steering control system for vehicle towing tractors through sensor.
[0013] Figure 2 illustrates a connection detailof the wheel steering control system.
[0014] Figure 3 illustrates a panel of the wheel steering control system.
[0015] Figure 4 illustrates a steering valve assembly.
[0016] Figure 5 illustrates configuration of a sensor with axle.
[0017] The figure depicts various embodiments of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0018] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising", “having”, and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, systems and methods are now described. The disclosed embodiments are merely exemplary of the disclosure, which may be embodied in various forms.
[0019] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. However, one of ordinary skill in the art will readily recognize that the present disclosure is not intended to be limited to the embodiments illustrated, but is to be accorded the widest scope consistent with the principles and features described herein.
[0020] The present subject matter relates with a wheel steering control system for vehicle towing tractors through a sensor, which senses wheel’s straight ahead position using the sensor in order to change over from one steering mode to another by maintaining stability factor while towing .
[0021] Referring now to figure 1, wherein figure 1 illustrates a schematic diagram of the wheel steering control system for vehicle towing tractors through the sensor. A cabin and chassis harnesses configured with a four-wheel steering an interface circuit’s (103) controller in order to control valve assembly. A system (100) comprises of a power supply (101) along with a protection circuit (102) to provide power to a logic and delay circuit (104). The interface circuit (103) is configured with the logic and delay circuit (104) in order to provide inputs. The logic and delay circuit (104) is configured with an output module (105) to fetch processed outcomes; further, the output module (105) transmits output signals to a solenoid (107). The logic and delay circuit (104) and the output module are having a memory (106), wherein the memory is used to store the steering mode, which was active prior to key switch off/power off. A steering mode selection switch (108) enables a driver to select a desired mode. The solenoids (107) are configured with a valve in order to operate the mode of steering selected by the driver.
[0022] Following are the list of modes along with their operations.
1. A Front Wheel Mode: In the front wheel mode, the steering controls only front wheel
2. A Rear Wheel Mode: In the rear mode, the steering controls only rear wheel and front wheels are in straight position
3. A Four Wheel Mode: In the four-wheel mode, the steering controls both front wheel and rear wheel. In this mode both front wheel and rear wheel will move in opposite direction
4. A Crab Wheel Mode: In the crab wheel mode, the steering controls both wheels in same direction
Aforesaid modes provides improved maneuverability, stability and smaller turning radius.
[0023] A steering mode selection switch (108) may be proximity switches. The system (100) receives the signal from the proximity switches. A gearshift lever transmits a gear neutral signal (113) to the system (100). In addition, the system (100) receives an emergency steering signal (112), a parking brake signal (111), a manual override signal (110), a front wheel signal (115) and a rear wheel signal (114). Following are the details of input provided to the system through the respective component.
Sr. No. Parameter Type Triggering Signal Normal Condition
1. Front wheel straight ahead position Proximity Sensor PNP (24V) 24 V
(Floating)
2. Rear wheel straight ahead position Proximity Sensor PNP (24V) 24 V
(Floating)
3. Steering mode selection Switch - -
4. Gear in neutral position Relay output Ground Open
5. Emergency steering system ON Ground Open
6. Parking brake applied Pressure Switch Ground Open
7. Manual override switch ON Toggle Switch - -
Table No. 1: Details of input provided to the system through the respective component.
[0024] In the wheel steering control system (100) based on mode selection the solenoids (106) are actuated in order to operate the vehicle in required steering mode. The system gets power from alternator – power (battery) supply (101) of 18-32 V DC, wherein power (battery) supply is integrated with protection circuit (102) in order to protect against overload, reverse polarity, transients, voltage fluctuations and electrical noise caused by operation of inductive loads like motor, horn, wiper, solenoid etc.
[0025] While selecting different steering modes the system (100) is provided with intelligent and safety interlocks. The driver enables the wheel steering control system (100) by selecting different modes, when the driver switched ON the system (100) for the steering mode selection then the ECU checks the last steering mode prior to key switch off and automatically switches over to that mode. For selection of new steering mode, it is necessary to have the gear in neutral position, the parking brake is applied and wheels must be in straight ahead position, wherein the conditions for wheels straight ahead position is sensed by the sensor (116) (front and rear) mounted on the axles.
[0026] If the emergency steering mode gets enabled, the vehicle remains in the current mode until the wheels comes into straight ahead position. The controller is switch over to front wheel steering mode once the wheels come into straight ahead position and enables driver to take a control. During this condition other steering modes are gets disabled even though it is operated or selected by the driver.
[0027] The driver performs the manual override selection, when the manual override switch is ON, any steering mode is selectable irrespective of wheel straight-ahead condition. However, it is necessary to have the gear in neutral position and applied parking brakes. The manual override mode is preferably used, when there is wheel synchronization error or sensor has failed. If manual override switch is ON upon detection of solenoid (106) error, the system (100) remains in the current steering mode until the error gets cleared.
[0028] In case of any solenoid (106) failure, the system enters into a default steering mode i.e., front wheel steering.
[0029] Referring to figure 2, wherein a connection detail of the wheel steering control system (100) is shown. The sensor (116) is configured with wheels in order to detect the wheel positions. The sensor (116) is configured with the interface (103) and solenoids (106) through the connector (117). The connector type is 19 pin male MIL-Connector (MS3F22-14P) is used to establish connections. Table 2. is showing pin configuration of the connector of the ECU.
CN - FWS
Pin Description Type Colour
A Power Supply Input .85R
B Ground Input .85B
C Front Axle Proximity Sensor Input .85GR
D Not Used - -
E Rear Axle Proximity Sensor Input .85YR
F Not Used - -
G Gear Neutral Input .85BY
H Emergency Steering “ON” Input .85GY
J Parking Brake Input .85WR
K Solenoid “S1” Output .85W
L Solenoid “S2” Output .85L
M Solenoid “S3” Output .85Y
N Solenoid “S4” Output .85G
P, R,S,T,U,V Not used - -
Table No. 2: Pin configuration of sensors and solenoids
[0030] Referring to figure 3, wherein a user interface (119) of wheel steering control system is shown. The user interface (119) enables the driver to select among four modes, wherein four modes are the front wheel steering, the rear wheel steering, the four wheel steering and the crab steering. The user interface comprises built in illumination type switches with legends for each steering mode. The various LEDs are configured on user interface (119) and upon the mode selection, the enabled actuation of each solenoid (106) is indicated by illumination of respective LED (i.e., green colour). The user interface (119) is having a common LED (i.e., red colour) for indicating any solenoid (106) failure. The LED’s FS (Front Wheel Sensor) and RS (Rear Wheel Sensor) glows whenever respective wheels are detected as straight in position by sensor. The illumination of Red LED (118) indicates error in the system (100).
[0031] Now referring to figure 4, whereina steering valve assembly is shown. The four solenoids S1,S2,S3 and S4 of 24 VDC (voltage dc) - 23 Watts, are used for controlling the different steering modes, upon selection of different modes the solenoids (106) gets energize and operates by means of allowing the pass of hydraulic oil in respective steering manifold. The details of solenoid (106) actuation is shown in Table 3. Various combinations of solenoids results into formation of the steering mode.
Steering Mode Solenoid Combination Interlock Interlock Signals
S1 S2 S3 S4
Front Wheel Steering N N N N Yes Axle shall be in straight ahead position and transmission in neutral gear and parking brake must be applied
Rear Wheel Steering N N Y N Yes
Four Wheel Steering Y Y N Y Yes
Crab Wheel Steering N Y N N Yes
N: off solenoid , Y: on solenoid
Table No. 3: Details of solenoid actuation
[0032] Now referring to figure 5, wherein configuration of an sensor (116) with axel is shown. In the system (100) the two numbers of PNP (9-24V, 800mA) sensors (116) are configured on the both Front and Rear axles. The sensor (116) sense the position of the wheel and transmits the signal (24V) to the four-wheel ECU, wherein sensed wheel position is in straight ahead position. The sensor (116) may be any one of proximity sensor.
[0033] In an embodiment, A wheel steering control system (100) comprises a steering mode select switch (108) configured to select a desired steering mode, an interface circuit (103) configured to processes the steering mode selection signal in ECU to activate the selected steering mode operation of the vehicle, plurality of sensors (116) configured to detect the wheel positions. An user interface (119) configured to indicate the steering mode selection and to display the detected error of the system (100) and a logic and delay circuit (104) configured to detect and store the last steering mode selected, before the vehicle is turned off and to restore the vehicle in last steering mode stored in ignition ON condition.
[0034] In the system (100) the various steering modes constitutes a front wheel mode, a rear wheel mode, a four-wheel mode and a crab wheel mode. The front wheel mode is configured to be selected by actuation of solenoids (S1-S4). The wheel mode is configured to be selected by actuation of the solenoid S3. The four wheel mode is configured to be selected by actuation of solenoids S1, S2, and S4.The crab wheel mode is configured to be selected by actuation of solenoid S2.
[0035] In the system (100) selection of a new steering mode is configured to be processed by ECU based on detection of a parking brake signal (111) and a gear neutral signal (113).
[0036] In the system (100), a manual override mode is configured to be activated based on detection of a manual override signal (110) from a manual override switch, the parking brake signal (111) and the gear neutral signal (113). The manual override mode is configured to be selected based on detection of at least one of system error viz wheel synchronization error or a failure of sensor (116) or a solenoid (106) failure error. The system (100) is configured to enter into default steering mode (front wheel steering mode) based on detection of the solenoid (106) failure error.
[0037] In the system (100), an emergency steering mode is configured to be activated upon receiving an emergency steering signal (112) to maintain the vehicle in current mode till the wheels come into straight ahead position and on detection of straight position of wheel the system (100) switch over to front wheel steering mode enabling driver to take control of the system (100).
[0038] Exemplary embodiments discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, the advantages may include those provided by the following features.
[0039] Some object of the present invention is sensing of wheel straight ahead position-using sensors in order to change over from one mode to another.
[0040] Some object of the present invention limits the larger turning radius while turning the towed air vehicle.
[0041] Some object of the present invention provides different steering modes with stability.
[0042] Some object of the present invention is to provide better maneuverability and compacted design, which is easy to operate with safety interlocks.
Part No. Part Name
101 Power Supply
102 Protection Circuit
103 Interface Circuit
104 Logic and Delay Circuit
105 Output Module
106 Solenoids
107 Memory
108 Steering Mode Selection Switch
109 Shift Lever
110 Manual Override Signal
111 Parking Brake Signal
112 Emergency Steering Signal
113 Gear Neutral Signal
114 Rear Wheel Signal
115 Front Wheel Signal
116 Sensor
117 Connector
118 Red LED
119 User Interface
,CLAIMS:
1. A wheel steering control system (100) comprises
a steering mode select switch (108) configured to select a desired steering mode;
an interface circuit (103) configured to processes the steering mode selection signal in ECU to activate the selected steering mode operation of the vehicle;
plurality of sensors (116) configured to detect the wheel positions;
atleast one user interface (119) configured to indicate the steering mode selection and to display the detected error of the system (100); and
a logic and delay circuit (104) configured to detect and store the last steering mode selected,before the vehicle is turned off and to restore the vehicle in last steering mode stored in ignition ON condition.
2. The system (100) as claimed in claim 1, wherein the various steering modes constitutesafront wheel mode, a rear wheel mode, a four-wheel mode and a crab wheel mode.
3. The system as claimed in claim 2, wherein the front wheel mode is configured to be selectedby actuation of solenoids (S1-S4).
4. The system (100) as claimed in claim 2, wherein the wheel mode is configured to be selectedby actuation of the solenoid S3.
5. The system (100) as claimed in claim 2, wherein the four wheelmode is configured to be selected byactuation of solenoids S1, S2, and S4.
6. The system (100) as claimed in claim 2, wherein the crab wheel mode is configured to be selectedby actuation ofsolenoid S2.
7. The system (100) as claimed in claim 1, wherein selection of a new steering mode is configured to be processed by ECUbased ondetection of a parking brake signal (111) and a gear neutral signal (113).
8. The system (100) as claimed in claim 1, wherein a manual override mode is configured to be activated based on detection of a manual override signal (110) from a manual override switch, theparking brake signal (111) and the gear neutral signal (113).
9. The system (100) as claimed in claim 8, wherein the manual override mode is configured to be selected based on detection of at least one of system errorviz wheel synchronization error or a failure of sensor (116) or a solenoid (106) failure error.
10. The system (100) as claimed in claim 9, wherein the system (100) is configured to enter into default steering mode (front wheel steering mode) based on detection of the solenoid (106) failure error.
11. The system (100) as claimed in claim 1, wherein an emergency steering mode is configured to be activated upon receiving an emergency steering signal (112) to maintain the vehicle in current mode till the wheels come into straight ahead position and on detection of straight position of wheel, the system (100) switch over to front wheel steering mode enabling driver to take control of the system (100).