Steering control method for special vehicle single front axle wheel and track composite walking system

Abstract

The application belongs to the technical field of amphibious special vehicle, and relates to a steering control method of a single front axle wheel and track composite walking system of a special vehicle. A sensor measures and obtains relevant parameters, and the relevant parameters are determined when the special vehicle is designed; a control component calculates (1) a steering inner track driving force F ti (2) a steering outer track driving force F to ; and the control component controls a driving motor to output a driving force with a value according to the calculated steering inner track driving force F ti and the steering outer track driving force F to . The steering control method of the single front axle wheel and track composite walking system of the special vehicle can be reliably applied to the special vehicle with the single front axle and track composite walking system, and can control the size of the track driving force in real time during driving steering, so that the wheel and track steering torques are consistent according to the bearing proportion, the wheel drags the track or the track drags the wheel is avoided, the additional load of the structure is reduced, the wheel and track are minimized in wear, and the performance is improved.

Description

Technical Field

[0001] This invention belongs to the field of amphibious special vehicle technology, and more specifically, it relates to a steering control method for a special vehicle's single front axle wheel and track composite walking system. Background Technology

[0002] Amphibious special vehicles possess characteristics such as "rapid and concealed movement on water, maneuverability and flexibility on land, and unique mobility at the interface between land and water," thus demonstrating their significant importance in both civilian transportation and military applications. The application of a wheel-track hybrid system in amphibious special vehicles enhances their mobility on beaches, ensuring efficient transportation needs. When these vehicles operate on beaches, the wheel-track hybrid system necessitates precise control of the driving force matching between the wheels and tracks during steering. This is crucial to preventing wheels from dragging tracks or tracks from dragging wheels, thereby reducing additional load on structural components and minimizing wheel and track wear. Currently, there is no information on wheel-track hybrid system control for the matching of driving force between the wheels and tracks during steering, making it impossible to prevent wheels from dragging tracks or tracks from dragging wheels, and thus failing to reduce additional load on structural components and minimize wheel and track wear.

[0003] Existing technology includes a tracked vehicle chassis entitled "A Tracked Vehicle Chassis for High-Speed ​​Travel," with publication number CN111572658B. This technology discloses a tracked vehicle chassis for high-speed travel, belonging to the field of chassis frame design and manufacturing technology. It includes a support mechanism, a walking mechanism, a vibration damping mechanism, a tensioning mechanism, and a drive mechanism. The drive mechanism uses axle-shaped drive wheels, working in conjunction with rubber toothed tracks and a high-speed hydraulic motor for high-speed travel. The walking mechanism includes end wheels and middle wheels, both movably connected to the support mechanism via damping springs and damping side plates of the vibration damping mechanism. The end damping mechanisms drive the wheels, buffering the downward recoil force and providing vibration damping. The middle damping mechanism reduces vertical vibration, and the two pairs of middle wheels further stabilize the vehicle's center of gravity. The tensioning mechanism tensions the tracks, and under the drive mechanism, the wheels work together to ensure stable vehicle movement. Additionally, limit grooves are provided below the end wheels to correct the relative position of the tracks and wheels, further ensuring stable vehicle operation. This technology does not address the issues and solutions of this application. Summary of the Invention

[0004] The technical problem to be solved by this invention is to provide a simple and reliable steering control method for a special vehicle with a single front axle wheel and track composite walking system, which can be reliably applied to special vehicles with a single front axle and track composite walking system. This method controls the magnitude of the track driving force in real time during driving and turning, so that the steering torque of the wheel and track is consistent according to the load ratio, avoiding the wheel dragging the track or the track dragging the wheel, thereby reducing the additional load on the structural components and minimizing the wear of the wheel and track, and improving the overall performance.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0006] This invention relates to a steering control method for a single front axle wheel and track composite mobility system of a special vehicle, characterized in that: the control steps of the steering control method for the single front axle wheel and track composite mobility system are as follows:

[0007] S1. The single front axle wheel and track composite travel system includes multiple sensors to measure and acquire the following parameters:

[0008] (1) Steering angle δ of the outer wheel o ,

[0009] (2) Steering angle δ of the inner wheel i ,

[0010] (3) Load G of the front axle (first axle) w ,

[0011] (4) Track normal load G t ,

[0012] (5) Steering inner wheel output torque T wi Outer wheel output torque T wo ;

[0013] S2. The following parameters shall be determined during the design of special vehicles;

[0014] (1) The distance K between the intersection of the extended lines of the center lines of the left and right kingpins of the front axle and the ground.

[0015] (2) The kingpin offset distance a on the wheel contact surface.

[0016] (3) Track center distance B,

[0017] (4) The distance L between the front axle and the center lines connecting the two side tracks c ,

[0018] (5) Ground contact length L of a single track t ;

[0019] S3. The control unit calculates the following values ​​according to the formula:

[0020] (1) Steering inside track driving force F ti ,

[0021] (2) Steering outer track driving force F to ;

[0022] S4. The control unit controls the drive motor to output the calculated inner track driving force F based on the steering angle. ti and steering outside track driving force F to The numerical driving force is used to achieve optimized steering inside track driving force F during steering. ti and steering outside track driving force F to To control the steering torque of special vehicles, so that the steering torque of the wheels and tracks of the special vehicles is consistent according to the load ratio;

[0023] S5. The control unit applies the steering force F to the inner track every 0.5-1.5 seconds. ti and steering outside track driving force F to The calculation and control components simultaneously determine the real-time steering inner track driving force F obtained from each calculation. ti and steering outside track driving force F to The calculated steering inner track driving force F is controlled by the drive motor output. ti and steering outside track driving force F to .

[0024] Track turning radius and equivalent track rotation axis (3) position and steering angle δ of the outer wheel o Steering angle δ of the inner wheel i They conform to a geometric relationship:

[0025] (1) Steering angle δ of the outer wheel o Geometric relationships that conform to the formula

[0026]

[0027] According to equation (1) above, we get:

[0028]

[0029] (2) Steering angle δ of the inner wheel i Geometric relationships that conform to the formula

[0030]

[0031] (3) Based on the steering angle δ o With δ iFrom the geometric relationships, the turning radius R of the track can be obtained, that is:

[0032]

[0033] (4) Substitute R into the formula to obtain the distance between the equivalent track pivot point and the front axle, i.e.:

[0034]

[0035] Calculation of the turning radius of the wheel:

[0036] The turning radius R of the outer turning wheel is obtained in terms of the track turning radius R. wo :

[0037]

[0038] Similarly, the turning radius R of the inner wheel, expressed in terms of the track turning radius R, is obtained. wi :

[0039]

[0040] The rolling resistance coefficient of the wheel is quite close to the ground deformation resistance coefficient of the track. In this patent, the same value is used as the driving resistance coefficient f (this coefficient is obtained from tests on different road surfaces), that is:

[0041] The driving resistance of a single wheel is transmitted through the axle load G. w The following can be obtained from the drag coefficient f:

[0042]

[0043] The running resistance of a single track can be controlled by the track normal load G. t The following can be obtained from the drag coefficient f:

[0044]

[0045] Calculation of track steering resistance:

[0046] The assumption is adopted that the tracked normal load is uniformly distributed along the ground contact section, i.e., the load pattern is rectangular; the ground turning resistance F z and normal load G t It is directly proportional, and its proportionality coefficient is represented by the steering resistance coefficient μ.

[0047]

[0048] Draw the normal load diagram and steering resistance distribution diagram of the grounding section, and then calculate the steering resistance at the front and rear of the grounding section;

[0049] The normal load p acting per unit length of the grounding section, through the track normal load G t and grounding section length L t Find:

[0050]

[0051] Given the normal load per unit length of the grounding segment, calculate the corresponding turning resistance F per unit length of the grounding segment. zd As assumed, the turning resistance per unit length of the grounding segment is also proportional to its normal load per unit length p, with the proportionality coefficient remaining μ.

[0052]

[0053] Acting on the ground contact sections of both tracks, equivalent to the front section of the track rotation axis (length L) ω1 ),

[0054]

[0055] Steering equivalent resistance F ts1 It can be expressed by the following formula:

[0056]

[0057] Similarly, the force acting on the ground contact sections of both tracks is equivalent to the rear section of the track rotation axis (length L). ω2 )

[0058]

[0059] Steering equivalent resistance F ts2 It can be expressed by the following formula:

[0060]

[0061] Since the vehicle rotates around point O, F ts1 With F ts2 The direction of action is exactly the opposite, the direction is as follows: Figure 1 As shown.

[0062] The steering resistance coefficient μ is calculated using formula (8):

[0063]

[0064] Where μ max This is the maximum steering resistance coefficient on the road surface, obtained from tests on different road surfaces.

[0065] The following three equations (18), (19), and (20) are obtained, which are the equilibrium equations for the x-direction force, y-direction force, and z-direction moment about point o in the Cartesian coordinate system:

[0066] F x =F w (sinδ o +sinδ i )-(F so -F rw cosδ o -(F si -F rw cosδ i -F to -F ti =0 Equation (18)

[0067] F y =-F w (cosδ o +cosδ i )-(F so -F rw sinδ o -(F si -F rw sinδ i +F ts1 -F ts2 =0 Equation (19)

[0068]

[0069] In the equation:

[0070] F w —The lateral force of wheel steering;

[0071] F so —The driving force for steering the outer wheel is of magnitude T wo Torque for steering the outer wheel;

[0072] r r The radius of the wheel's rolling radius;

[0073] F si —The driving force for steering the inner wheel is of magnitude T wi For the torque of the steering inner wheel, r r The radius of the wheel's rolling radius;

[0074] F to —The driving force for steering the outer track;

[0075] F ti —The driving force for steering the inner track;

[0076] Solving equation (19), we get:

[0077]

[0078] Rearranging equations (18) and (20), we get:

[0079]

[0080]

[0081] Let the relation on the right side of equations (22) and (23) be:

[0082] F x ′=F w (sinδ o +sinδ i )-(F so -F rw cosδ o -(F si -F rw cosδ i Equation (24)

[0083]

[0084] Equations (22) and (23) can be simplified to the following system of equations:

[0085]

[0086] Solving the system of equations, we get:

[0087]

[0088]

[0089] When the special vehicle reverses, the inner track driving force F ti External track driving force F to Based on the control equations for forward movement, the forces acting in each direction are substituted into the equations according to the steering forces during reverse movement. Forces acting in opposite directions are converted to negative values. The inner track driving force F during reverse movement is then obtained from the corresponding control equations. ti External track driving force F to The control unit controls the drive motor to output the calculated steering inner track driving force F. ti and steering outside track driving force F to .

[0090] The working principle and beneficial effects of the technical solution adopted in this invention are as follows:

[0091] The steering control method of the special vehicle single front axle wheel and track composite walking system described in this invention can be reliably applied to special vehicles with a single front axle and track composite walking system. During driving and steering, the magnitude of the track driving force is controlled in real time, so that the steering torque of the wheel and track is consistent according to the load ratio, avoiding the wheel dragging the track or the track dragging the wheel, thereby reducing the additional load on the structural components and minimizing the wear of the wheel and track, and improving performance. Attached Figure Description

[0092] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein:

[0093] Figure 1 This is a schematic diagram illustrating the relationship of traction force when the single front axle wheel and track composite walking system described in this invention is moving forward.

[0094] Figure 2 This is a schematic diagram of the steering forces during forward movement of the single front axle wheel and track composite walking system described in this invention.

[0095] Figure 3 This is a schematic diagram showing the traction force relationship of the single front axle wheel and track composite walking system described in this invention when it is reversing.

[0096] The labels in the attached diagram are as follows: 1. Wheel; 2. Track; 3. Equivalent track rotation axis. Detailed Implementation

[0097] The following description, with reference to the accompanying drawings, provides a more detailed explanation of the specific embodiments of the present invention, including the shape and structure of each component, the relative positions and connections between the parts, the functions and working principles of each part:

[0098] As attached Figure 1 -Appendix Figure 3 As shown, this invention discloses a steering control method for a single front axle wheel and track composite mobility system for special vehicles. The method utilizes the driving force F of the inner track during steering. ti Outer track driving force F to The calculation and output control of the internal track driving force F are controlled in real time. ti External track driving force F to The size of the internal track drive force F is designed to ensure that special vehicles obtain optimal internal track drive force F when turning while driving on the beach. ti External track driving force F to This causes the internal track driving force F ti External track driving force F to Steering angle δ of the inner wheel i Steering angle δ of the outer wheel oand inner wheel output torque T wi Outer wheel output torque T wo This system matches the tracks to prevent them from dragging each other, thus reducing the additional load on structural components and minimizing wear on both wheels and tracks, effectively improving the mobility of special vehicles on riverbanks. The present invention provides an analytical model of the relationship between wheel steering angle and track traction force in a single front axle wheel-track composite walking system. The front axle is a single axle, and the steering force relationship of the special vehicle moving forward is as follows: Figure 1 As shown in the figure. Parameter descriptions in the figure:

[0099] (1)δ o —Steering angle of the outer wheel.

[0100] (2)δ i —Steering angle of the inner wheel.

[0101] (3) K——The distance between the intersection of the extension line of the left and right main pin center lines of bridge 1 and the ground.

[0102] (4)a——The offset distance of the kingpin on the ground surface of the wheel.

[0103] (5)R wo — The turning radius of the outer wheel.

[0104] (6)R wi —The turning radius of the inner wheel.

[0105] (7)B——track center distance.

[0106] (8)L c — The distance between bridge 1 and the line connecting the centers of the tracks on both sides.

[0107] (9)L t — The ground contact length of a single track.

[0108] (10)L k — The distance between the bridge and the equivalent track rotation axis.

[0109] (11) R - Turning radius of the track.

[0110] (12)L w1 — Track ground contact section, equivalent to the front section of the track rotation axis.

[0111] (13)L w2 — Track ground contact section, equivalent to the rear section of the track rotation axis.

[0112] The control steps of the steering control method for the single front axle wheel and track composite travel system are as follows:

[0113] S1. The single front axle wheel and track composite travel system includes multiple sensors to measure and acquire the following parameters:

[0114] (1) Steering angle δ of the outer wheel o ,

[0115] (2) Steering angle δ of the inner wheel i ,

[0116] (3) Load G of the front axle (first axle) w ,

[0117] (4) Track normal load G t ,

[0118] (5) Steering inner wheel output torque T wi Outer wheel output torque T wo ;

[0119] S2. The following parameters shall be determined during the design of special vehicles;

[0120] (1) The distance K between the intersection of the extended lines of the center lines of the left and right kingpins of the front axle and the ground.

[0121] (2) The kingpin offset distance a on the wheel contact surface.

[0122] (3) Track center distance B,

[0123] (4) The distance L between the front axle and the center lines connecting the two side tracks c ,

[0124] (5) Ground contact length L of a single track t ;

[0125] S3. The control unit calculates the following values ​​according to the formula:

[0126] (1) Steering inside track driving force F ti ,

[0127] (2) Steering outer track driving force F to ;

[0128] S4. The control unit controls the drive motor to output the calculated inner track driving force F based on the steering angle. ti and steering outside track driving force F to The numerical driving force is used to achieve optimized steering inside track driving force F during steering. ti and steering outside track driving force F to To control the steering torque of special vehicles, so that the steering torque of the wheels and tracks of the special vehicles is consistent according to the load ratio;

[0129] S5. The control unit applies the steering force F to the inner track every 0.5-1.5 seconds. ti and steering outside track driving force F to The calculation and control components simultaneously determine the real-time steering inner track driving force F obtained from each calculation. ti and steering outside track driving force F to The calculated steering inner track driving force F is controlled by the drive motor output. ti and steering outside track driving force F to .

[0130] In the method of this invention, sensor measurement parameters and geometric design parameters are used as inputs and substituted into the calculation equations described above to obtain the optimal inner track driving force F for the special vehicle during steering. ti External track driving force F to Then, the corresponding inner track driving force F is input in real time through the control components. ti External track driving force F to The driving force ensures that the steering torque of the wheels and tracks is proportional to the load. This is achieved by real-time control of the inner and outer track driving forces F. ti F to The size of the wheel and track is designed to prevent the wheel from dragging the track or the track from dragging the wheel during the entire steering process, thereby reducing the additional load on the structural components and minimizing the wear on both the wheel and track.

[0131] 1. Track turning radius and equivalent track rotation axis position:

[0132] Track turning radius and equivalent track rotation axis position 3 and steering angle δ of the outer wheel o Steering angle δ of the inner wheel i They conform to a geometric relationship:

[0133] (1) Steering angle δ of the outer wheel o Geometric relationships that conform to the formula

[0134]

[0135] According to equation (1) above, we get:

[0136]

[0137] (2) Steering angle δ of the inner wheel i Geometric relationships that conform to the formula

[0138]

[0139] (3) Based on the steering angle δ o With δ iFrom the geometric relationships, the turning radius R of the track can be obtained, that is:

[0140]

[0141] (4) Substitute R into the formula to obtain the distance between the equivalent track pivot point and the front axle, i.e.:

[0142]

[0143]

[0144] 2. Wheel turning radius:

[0145] Calculation of the turning radius of the wheel:

[0146] The turning radius R of the outer turning wheel is obtained in terms of the track turning radius R. wo :

[0147]

[0148] Similarly, the turning radius R of the inner wheel, expressed in terms of the track turning radius R, is obtained. wi :

[0149]

[0150] 3. Driving resistance

[0151] The rolling resistance coefficient of the wheel is quite close to the ground deformation resistance coefficient of the track. In this patent, the same value is used as the driving resistance coefficient f (this coefficient is obtained from tests on different road surfaces), that is:

[0152] The driving resistance of a single wheel is transmitted through the axle load G. w The following can be obtained from the drag coefficient f:

[0153]

[0154] The running resistance of a single track can be controlled by the track normal load G. t The following can be obtained from the drag coefficient f:

[0155]

[0156] 4. Track steering resistance:

[0157] Calculation of track steering resistance:

[0158] The assumption is adopted that the tracked normal load is uniformly distributed along the ground contact section, i.e., the load pattern is rectangular; the ground turning resistance F z and normal load G t It is directly proportional, and its proportionality coefficient is represented by the steering resistance coefficient μ.

[0159]

[0160] Draw the normal load diagram and steering resistance distribution diagram of the grounding section, and then calculate the steering resistance at the front and rear of the grounding section;

[0161] The normal load p acting per unit length of the grounding section, through the track normal load G t and grounding section length L t Find:

[0162]

[0163] Given the normal load per unit length of the grounding segment, calculate the corresponding turning resistance F per unit length of the grounding segment. zd As assumed, the turning resistance per unit length of the grounding segment is also proportional to its normal load per unit length p, with the proportionality coefficient remaining μ.

[0164]

[0165] Acting on the ground contact sections of both tracks, equivalent to the front section of the track rotation axis (length L) ω1 ),

[0166]

[0167] Steering equivalent resistance F ts1 It can be expressed by the following formula:

[0168]

[0169] Similarly, the force acting on the ground contact sections of both tracks is equivalent to the rear section of the track rotation axis (length L). ω2 )

[0170]

[0171] Steering equivalent resistance F ts2 It can be expressed by the following formula:

[0172]

[0173] Since the vehicle rotates around point O, F ts1 With F ts2 The direction of action is exactly the opposite, the direction is as follows: Figure 1 As shown.

[0174] The steering resistance coefficient μ is calculated using formula (8):

[0175]

[0176] Where μ maxThis is the maximum steering resistance coefficient on the road surface, obtained from tests on different road surfaces.

[0177] 5. Driving force of the inner and outer tracks:

[0178] The following three equations (18), (19), and (20) are obtained, which are the equilibrium equations for the x-direction force, y-direction force, and z-direction moment about point o in the Cartesian coordinate system:

[0179] F x =F w (sinδ o +sinδ i )-(F so -F rw cosδ o -(F si -F rw cosδ i -F to -F ti =0 Equation (18)

[0180] F y =-F w (cosδ o +cosδ i )-(F so -F rw sinδ o -(F si -F rw sinδ i +F ts1 -F ts2 =0 Equation (19)

[0181]

[0182] In the equation:

[0183] F w —The lateral force of wheel steering;

[0184] F so —The driving force for steering the outer wheel is of magnitude

[0185] T wo Torque for steering the outer wheel;

[0186] r r The radius of the wheel's rolling radius;

[0187] F si —The driving force for steering the inner wheel is of magnitude

[0188] Twi For the torque of the steering inner wheel, r r The radius of the wheel's rolling radius;

[0189] F to —The driving force for steering the outer track;

[0190] F ti —The driving force for steering the inner track;

[0191] Solving equation (19), we get:

[0192]

[0193] Rearranging equations (18) and (20), we get:

[0194]

[0195]

[0196] Let the relation on the right side of equations (22) and (23) be:

[0197] F x ′=F w (sinδ o +sinδ i )-(F so -F rw cosδ o -(F si -F rw cosδ i Equation (24)

[0198]

[0199] Equations (22) and (23) can be simplified to the following system of equations:

[0200]

[0201] Solving the system of equations, we get:

[0202]

[0203]

[0204] 6. Track drive force control during reverse movement:

[0205] The steering force relationship of a single front axle wheel and track composite running system when reversing, such as... Figure 2 As shown.

[0206] When the special vehicle reverses, the inner track driving force F ti External track driving force Fto Based on the control equations for forward movement, the forces acting in each direction are substituted into the equations according to the steering forces during reverse movement. Forces acting in opposite directions are converted to negative values. The inner track driving force F during reverse movement is then obtained from the corresponding control equations. ti External track driving force F to The control unit controls the drive motor to output the calculated steering inner track driving force F. ti and steering outside track driving force F to .

[0207] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any improvements made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. A steering control method for a special vehicle's single front axle wheel and track composite walking system, characterized in that: The control steps of the steering control method for the single front axle wheel and track composite travel system are as follows: S1. The single front axle wheel and track composite travel system includes multiple sensors, which measure and acquire the following parameters: (1) Steering angle of the outer wheel , (2) Steering angle of the inner wheel , (3) Load on the front axle , (4) Track normal load , (5) Steering inner wheel output torque External wheel output torque ; S2. The following parameters shall be determined during the design of special vehicles: (1) Distance between the intersection of the extended lines of the center lines of the left and right kingpins of the front axle and the ground. , (2) Kingpin offset distance on the wheel contact surface , (3) Track center distance , (4) Distance between the front axle and the line connecting the center of the two side tracks , (5) Ground contact length of one side of the track ; S3. The control unit calculates the following values: (1) Steering inside track driving force , (2) Steering force of the outer track ; S4. The control unit controls the drive motor to output the calculated driving force of the inner track. and steering outside track drive force The numerical driving force is used to achieve optimized inner track driving force during steering. and steering outside track drive force To control the steering torque of special vehicles, so that the steering torque of the wheels and tracks of the special vehicles is consistent according to the load ratio; S5. The control unit applies steering force to the inner track every 0.5-1.5 seconds. and steering outside track drive force The calculation and control components simultaneously determine the real-time steering force of the inner track based on each calculation. and steering outside track drive force The calculated steering inner track driving force is controlled by the drive motor output. and steering outside track drive force ; Calculation of track steering resistance: Assuming the track normal load is uniformly distributed along the ground contact section; ground steering resistance. and normal load Proportional to the steering drag coefficient, its proportionality coefficient is proportional to the steering drag coefficient. express, Equation (10) Draw the normal load diagram and steering resistance distribution diagram of the grounding section, and then calculate the steering resistance at the front and rear of the grounding section; Normal load acting per unit length of grounding section Through the track normal load and grounding section length Find: Equation (11) Given the normal load per unit length of the grounding segment, calculate the corresponding turning resistance per unit length of the grounding segment. As assumed, the turning resistance per unit length of the grounding segment and its normal load per unit length are... It is also directly proportional, and the proportionality coefficient remains the same. : Equation (12) Acting on the ground contact sections of both tracks, equivalent to the length of the front section of the track rotation axis. , Equation (13) Steering equivalent resistance It can be expressed by the following formula: Equation (14) This is the distance between the front axle and the equivalent track rotation axis.

2. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 1, characterized in that: The action is applied to the ground contact sections of both tracks, equivalent to the length of the rear section of the track rotation axis. , Equation (15) Steering equivalent resistance It can be expressed by the following formula: Equation (16) Due to the vehicle's detour Point rotation, therefore and The direction of their effect is exactly the opposite. Steering drag coefficient Calculated using the following formula: Equation (17) in This is the maximum steering resistance coefficient of the road surface.

3. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 1, characterized in that: Track turning radius and equivalent track rotation axis (3) position and steering angle of the outer wheel Steering angle of the inner wheel They conform to a geometric relationship: (1) Steering angle of the outer wheel Geometric relationships that conform to the formula Equation (1) According to the above formula (1), we get: Equation (2); This is the distance between the front axle and the equivalent track rotation axis; This represents the turning radius of the track.

4. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 3, characterized in that: (2) Steering angle of the inner wheel Geometric relationships that conform to the formula Equation (3) (3) Based on the steering angle and Based on the geometric relationships, the turning radius of the tracks can be determined. ,Right now ， ， ， ， Equation (4).

5. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 4, characterized in that: (4) Substituting into the formula, we obtain the distance between the equivalent track pivot point and the front axle, i.e.: ， Equation (5).

6. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 5, characterized in that: The calculation of the turning radius of the wheel is as follows: Obtain the turning radius of the track The indicated steering radius of the outer wheel. : Equation (6); Similarly, the turning radius of the tracks is obtained. The indicated steering radius of the inner wheel. : Equation (7); The kingpin offset distance on the wheel's contact surface.

7. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 6, characterized in that: The rolling resistance coefficient of wheels is quite close to the ground deformation resistance coefficient of tracks, so we take the same value as the running resistance coefficient. ,Right now: The driving resistance of a single wheel is transmitted through the axle load. and driving drag coefficient Find: Equation (8) The running resistance of a single track can be controlled by the track's normal load. and driving drag coefficient Find: Equation (9).

8. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 1, characterized in that: We obtain the following three equations (18), (19), and (20), which are respectively in the Cartesian coordinate system. Directional force, Directional force, rotation Pointed Directional moment balance equation: Equation (18) Equation (19) Equation (20) In the equation: —The lateral force of wheel steering; —The driving force for steering the outer wheel is of magnitude ; Torque for steering the outer wheel; The radius of the wheel's rolling radius; —The driving force for steering the inner wheel is of magnitude , For the torque of the steering inner wheel, The radius of the wheel's rolling radius; —The driving force for steering the outer track; —The driving force for steering the inner track; Solving equation (19), we get: Equation (21).

9. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 8, characterized in that: Rearranging equations (18) and (20), we get: Equation (22) Equation (23) Let the relation on the right side of equations (22) and (23) be: Equation (24) Equation (25) Simplify (22) and (23) into the following system of equations: Equation (26) Solving the system of equations, we get: Equation (27) Equation (28).

10. The steering control method for a special vehicle single front axle wheel and track composite walking system according to claim 9, characterized in that: When the special vehicle reverses, the inner track driving force External track drive Based on the control equations for forward movement, the forces acting in each direction are substituted into the equations according to the steering forces during reverse movement. Forces acting in opposite directions are converted to negative values. The inner track driving force during reverse movement is then obtained from the corresponding control equations. External track drive The control unit controls the drive motor to output the calculated steering inner track driving force. and steering outside track drive force .

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