Steering control method for all-wheel drive multi-wheel and track composite walking system of special vehicle

Abstract

The application belongs to the technical field of amphibious special vehicle, and relates to a steering control method of a full-drive multi-wheel and track composite walking system of a special vehicle. A sensor measures and obtains relevant parameters; relevant parameters are determined during design; a control component calculates a steering inner track driving force F ti , a steering outer track driving force F to ; the control component controls driving motors to output the steering inner track driving force F ti and the steering outer track driving force F to according to the calculated values. The steering control method of the full-drive multi-wheel and track composite walking system of the special vehicle can control the steering angles of each wheel and the driving force of the track in real time during steering, so that the equivalent turning radii of the wheels and the track are consistent, the steering torques are consistent according to the bearing proportion, the steering is smooth, the wheels do not drag the track or the track does not drag the wheels, the additional load of the structure is reduced, the wear of the wheels and the track is minimized, and the overall 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 all-wheel drive multi-wheel and tracked 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 considerable importance in both civilian transportation and military applications. In all-wheel drive multi-wheel steering and tracked composite driving systems, the coordinated control of the steering angles between multiple wheels during vehicle steering, and the matching control of the driving force between each wheel and track, are crucial for smooth steering, preventing wheels from dragging tracks or tracks from dragging wheels, reducing additional load on structural components, and minimizing wheel and track wear. Currently, there is no control over the steering angles of each wheel during vehicle steering in all-wheel drive multi-wheel steering and tracked composite driving systems, resulting in unsmooth steering, failure to prevent wheels from dragging tracks or tracks from dragging wheels, and an inability 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 special vehicles with all-wheel drive multi-wheel steering and tracked composite mobility systems. This method allows for real-time control of the steering angle of each wheel and the magnitude of the track driving force during driving and steering, ensuring that the equivalent turning radius of the wheels and tracks are consistent and the steering torque is consistent according to the load ratio. This achieves smooth steering, avoids wheels dragging tracks or tracks dragging wheels, reduces the additional load on structural components, minimizes wear on both wheels and tracks, and improves 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 special vehicle's all-wheel drive multi-wheel and tracked hybrid mobility system. The control steps of the steering control method for the special vehicle's all-wheel drive multi-wheel and tracked hybrid mobility system are as follows:

[0007] S1. Special vehicles include single-axle, double-axle, and triple-axle vehicles. The all-wheel drive multi-wheel and tracked composite walking system includes multiple sensors, which measure and acquire the following parameters:

[0008] (1) Steering angle δ of the outer wheel of the axle o1 ,

[0009] (2) Steering angle δ of the inner wheel of the first axle i1 ,

[0010] (3) Load G of a bridge w1 ,

[0011] (4) Load G of the second bridge w2 ,

[0012] (5) Load G of the three bridges w3 ,

[0013] (6) Track normal load G t ,

[0014] (7) Output torque T of the inner and outer wheels of the steering axle wi1 T wo1 ,

[0015] (8) Output torque T of the inner and outer wheels of the second axle steering wheel wi2 T wo2 ,

[0016] (9) Output torque T of the inner and outer wheels of the three-axle steering wheel wi3 T wo3 ;

[0017] S2. The following parameters shall be determined during the design of special vehicles:

[0018] (1) The distance K between the intersection of the extended lines of the left and right main pin centerlines of the bridge and the ground.

[0019] (2) The kingpin offset distance a on the wheel contact surface.

[0020] (3) Track center distance B,

[0021] (4) The distance L between the bridge and the line connecting the centers of the two tracks c ,

[0022] (5) The distance L1 between the first bridge and the second bridge,

[0023] (6) The distance L2 between the first bridge and the third bridge,

[0024] (7) Ground contact length L of a single track t ;

[0025] S3. The control unit calculates the following values:

[0026] (1) Steering angle δ of the outer wheel of the second axle o2 ,

[0027] (2) Steering angle δ of the inner wheel of the second axle i2 ,

[0028] (3) Steering angle δ of the outer wheel of the three-axle steering wheel o3 ,

[0029] (4) Steering angle δ of the inner wheel of the three-axle steering wheel i3 ,

[0030] (5) Steering inside track driving force F ti ,

[0031] (6) Steering outside track driving force F to ;

[0032] S4. The control unit controls the drive motor to output the calculated inner track driving force F based on the steering force. 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;

[0033] 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 toThe 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 .

[0034] Track turning radius and equivalent track rotation axis position relative to the steering angle δ of the outer wheel of the first axle o1 Steering angle δ on the inner side of the bridge i1 The geometric relationship between them is as follows:

[0035] (1) Steering angle δ of the outer side of the bridge o1 Geometric relations that conform to the formula:

[0036]

[0037] According to equation (1) above, we get:

[0038]

[0039] (2) Steering angle δ on the inner side of the bridge i1 Geometric relations that conform to the formula:

[0040]

[0041] (3) Based on the steering angle δ o1 With δ i1 From the geometric relationships, the turning radius R of the track can be obtained, that is:

[0042]

[0043]

[0044] (4) Substitute R into the formula to obtain the distance between the equivalent track pivot position and the first axle, i.e.:

[0045]

[0046] (1) Steering angle δ of the outer wheel of the second axle o2 Geometric relations that conform to the formula:

[0047]

[0048] Therefore, the steering angle δ of the outer wheel of the second axle is obtained. o2 :

[0049]

[0050] (2) Steering angle δ of the inner wheel of the second axle i2 Geometric relations that conform to the formula:

[0051]

[0052] Therefore, the steering angle δ of the inner wheel of the second axle is obtained. i2 :

[0053]

[0054] (3) Steering angle δ of the outer wheel of the three-axle steering wheel o3 Geometric relations that conform to the formula:

[0055]

[0056] Therefore, the steering angle δ of the outer wheel of the three-axle steering wheel is obtained. o3 :

[0057]

[0058] (4) Steering angle δ of the inner wheel of the three-axle steering wheel i3 Geometric relations that conform to the formula:

[0059]

[0060] Therefore, the steering angle δ of the inner wheel of the three-axle steering wheel is obtained. i3 :

[0061]

[0062] (1) The turning radius R of the outer wheel of the axle is expressed as the turning radius R of the track. o1 :

[0063]

[0064] (2) The turning radius R of the inner wheel of the axle, expressed as the track turning radius R. i1 :

[0065]

[0066] (3) The turning radius R of the outer wheel of the second axle, expressed as the track turning radius R. o2 :

[0067]

[0068] (4) The turning radius R of the inner wheel of the second axle, expressed as the track turning radius R. i2 :

[0069]

[0070] (5) The turning radius R of the outer wheel of the three-axle steering wheel, expressed as the track turning radius R. o3 :

[0071]

[0072] (6) The turning radius R of the inner wheel of the three-axle steering wheel, expressed as the track turning radius R. i3 :

[0073]

[0074] The steering lateral force of the wheels on each of the three axles (first, second, and third axles) and the load G on the first axle. w1 Second bridge load G w2 Three-bridge load G w3 The relationship between the lateral force coefficient λ and the lateral force coefficient is as follows:

[0075] (1) Lateral force of the wheels of the first axle during steering

[0076]

[0077] (2) Lateral force of the second axle wheels during steering

[0078]

[0079] (3) Lateral steering force of the three-axle wheels:

[0080]

[0081] The driving resistance of a single wheel is transmitted through the load G of the axle. w1 Second bridge load G w2 Three-bridge load G w3 The following can be obtained from the drag coefficient f:

[0082] (1) Wheel resistance of the first axle:

[0083]

[0084] (2) Resistance of the second axle wheels:

[0085]

[0086] (3) Resistance of the three-axle wheels:

[0087]

[0088] The running resistance of a single track is transmitted through the track's normal load G. t The following can be obtained from the drag coefficient f:

[0089]

[0090] Ground steering resistance F z and normal load G t It is directly proportional, and its proportionality coefficient is represented by the steering drag coefficient μ:

[0091]

[0092] 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;

[0093] 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:

[0094]

[0095] 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 The turning resistance per unit length of the grounding segment is proportional to its normal load per unit length p, and the proportionality coefficient remains μ.

[0096]

[0097] The action is applied to the ground contact sections of both tracks, with the equivalent length L of the front section of the track rotation axis. ω1 :

[0098]

[0099] Steering equivalent resistance F ts1 It can be expressed by the following formula:

[0100]

[0101] Similarly, the force acting on the ground contact sections of both tracks is equivalent to the length L of the rear section of the track rotation axis. ω2 :

[0102]

[0103] Steering equivalent resistance F ts2 It can be expressed by the following formula:

[0104]

[0105] Since the vehicle rotates around point O, F ts1 With F ts2 The direction of their effect is exactly the opposite.

[0106] The steering resistance coefficient μ is calculated using formula (8):

[0107]

[0108] Where μ max This is the maximum steering resistance coefficient on the road surface, obtained from tests on different road surfaces.

[0109] When a vehicle turns while traveling at low and constant speed, ignoring the influence of lateral acceleration, the balance relationship between force and torque is satisfied, as shown in equations (35), (36), and (37), which are the balance equations of force in the x-direction, force in the y-direction, and torque in the z-direction about point o in the Cartesian coordinate system:

[0110]

[0111]

[0112]

[0113] Substituting equations (23), (24), and (25) into equation (36):

[0114]

[0115] Let equation (38) be...

[0116]

[0117] G′ w =G w1 (cosδ o1 +cosδ i1 )+G w2 (cosδ o2 +cosδ i2 )+G w3 (cosδ o3 +cosδ i3 Equation (40)

[0118] Solving equation (38), we get:

[0119]

[0120] then:

[0121]

[0122]

[0123]

[0124] Rearranging equations (35) and (37), we get:

[0125]

[0126]

[0127] Let the relation on the right side of equations (45) and (46) be:

[0128]

[0129]

[0130] Equations (45) and (46) can be simplified to the following system of equations:

[0131]

[0132] Solving the system of equations, we get:

[0133]

[0134]

[0135] 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 .

[0136] The working principle and beneficial effects of the technical solution adopted in this invention are as follows:

[0137] The steering control method for a special vehicle's all-wheel drive multi-wheel and tracked composite walking system described in this invention has simple steps and can be reliably applied to special vehicles with an all-wheel drive multi-wheel steering and tracked composite walking system. During driving and steering, the method controls the steering angle of each wheel and the magnitude of the track driving force in real time, so that the equivalent turning radius of the wheels and tracks is consistent, and the steering torque is consistent according to the load ratio, achieving smooth steering, avoiding wheels dragging tracks or tracks dragging wheels, thereby reducing the additional load on structural components and minimizing the wear of both wheels and tracks, and improving overall performance. Attached Figure Description

[0138] The following is a brief explanation of the contents depicted in the accompanying drawings and the markings therein:

[0139] Figure 1This is a schematic diagram illustrating the traction relationship analysis of the all-wheel drive multi-wheel and tracked composite walking system for special vehicles described in this invention.

[0140] Figure 2 This is a schematic diagram of the geometric parameters of the special vehicle all-wheel drive multi-wheel and track composite walking system described in this invention;

[0141] Figure 3 This is a schematic diagram of the steering forces of the all-wheel drive multi-wheel and tracked composite walking system for special vehicles described in this invention;

[0142] Figure 4 This is a schematic diagram showing the traction force relationship of the all-wheel drive multi-wheel and tracked composite walking system of the special vehicle described in this invention when it is reversing.

[0143] The labels in the attached diagram are as follows: 1. Wheel; 2. Track; 3. Equivalent track rotation axis; 4. First axle; 5. Second axle; 6. Third axle. Detailed Implementation

[0144] 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:

[0145] As attached Figure 1 - Appendix Figure 4 As shown, this invention discloses a steering control method for a special vehicle's all-wheel drive multi-wheel and tracked composite mobility system. Specifically, taking a special vehicle with a 6×6 all-wheel steering and tracked composite mobility system as an example, the steering angle of each wheel is controlled in real time using the steering angle control equation of each wheel. The steering angle is then controlled by the inner track driving force F. 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 optimized so that special vehicles can obtain the 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 o and inner wheel output torque T wi Outer wheel output torque T woThis design ensures proper matching to prevent wheel-to-wheel or wheel-to-track drag during vehicle movement, thereby reducing additional load on structural components and minimizing wear on both wheels and tracks. This effectively improves the mobility of special vehicles on riverbanks. This invention can be achieved through the following method: a 6×6 all-wheel steering and tracked composite mobility system. Taking this system as an example, the relationship between wheel steering angle and track traction is analyzed. The front axle is a single axle, and the rear axles are a second and third axle. The steering force relationship of the all-wheel steering and tracked composite mobility system during forward movement is as follows: Figure 1 As shown.

[0146] The geometric parameters in this invention are described below:

[0147] (1)δ o1 —Steering angle of the outer wheel of the bridge.

[0148] (2)δ i1 —Steering angle of the inner wheel of the bridge.

[0149] (3)δ o2 —Steering angle of the outer wheel of the second axle.

[0150] (4)δ i2 —Steering angle of the inner wheel of the second axle.

[0151] (5)δ o3 —Steering angle of the outer wheel of the three-axle steering system.

[0152] (6)δ i3 —Steering angle of the inner wheel of the three-axle steering system.

[0153] (7) K - The distance between the intersection of the extended lines of the left and right kingpin center lines of the axle and the ground.

[0154] (8)a——The offset distance of the kingpin on the ground surface of the wheel.

[0155] (9)R o1 —The turning radius of the outer wheel of the axle.

[0156] (10)R i1 —The turning radius of the inner wheel of the axle.

[0157] (11)R o2 —The steering radius of the outer wheel of the second axle.

[0158] (12)R i2 —The steering radius of the inner wheel of the second axle.

[0159] (13)R o3 —The steering radius of the outer wheel of the three-axle steering system.

[0160] (14)R i3 —The steering radius of the inner wheel of the three-axle steering system.

[0161] (15)B——track center distance.

[0162] (16)L c — The distance between the bridge and the line connecting the centers of the tracks on both sides.

[0163] (17)L1——Distance between the first bridge and the second bridge.

[0164] (18)L2——Distance between the first and third bridges.

[0165] (19)L t — The ground contact length of a single track.

[0166] (20)L k — The distance between the bridge and the equivalent track rotation axis.

[0167] (21) R——Turning radius of the track.

[0168] (22)L w1 — Track ground contact section, equivalent to the front section of the track rotation axis.

[0169] (23)L w2 — Track ground contact section, equivalent to the rear section of the track rotation axis.

[0170] The control steps of the steering control method for the special vehicle all-wheel drive multi-wheel and tracked composite walking system are as follows:

[0171] S1. Special vehicles include single-axle, double-axle, and triple-axle vehicles. The all-wheel drive multi-wheel and tracked composite walking system includes multiple sensors, which measure and acquire the following parameters:

[0172] (1) Steering angle δ of the outer wheel of the axle o1 ,

[0173] (2) Steering angle δ of the inner wheel of the first axle i1 ,

[0174] (3) Load G of a bridge w1 ,

[0175] (4) Load G of the second bridge w2 ,

[0176] (5) Load G of the three bridges w3 ,

[0177] (6) Track normal load G t ,

[0178] (7) Output torque T of the inner and outer wheels of the steering axle wi1 T wo1 ,

[0179] (8) Output torque T of the inner and outer wheels of the second axle steering wheel wi2 T wo2 ,

[0180] (9) Output torque T of the inner and outer wheels of the three-axle steering wheel wi3 T wo3 ;

[0181] S2. The following parameters shall be determined during the design of special vehicles:

[0182] (1) The distance K between the intersection of the extended lines of the left and right main pin centerlines of the bridge and the ground.

[0183] (2) The kingpin offset distance a on the wheel contact surface.

[0184] (3) Track center distance B,

[0185] (4) The distance L between the bridge and the line connecting the centers of the two tracks c ,

[0186] (5) The distance L1 between the first bridge and the second bridge,

[0187] (6) The distance L2 between the first bridge and the third bridge,

[0188] (7) Ground contact length L of a single track t ;

[0189] S3. The control unit calculates the following values:

[0190] (1) Steering angle δ of the outer wheel of the second axle o2 ,

[0191] (2) Steering angle δ of the inner wheel of the second axle i2 ,

[0192] (3) Steering angle δ of the outer wheel of the three-axle steering wheel o3 ,

[0193] (4) Steering angle δ of the inner wheel of the three-axle steering wheel i3 ,

[0194] (5) Steering inside track driving force F ti ,

[0195] (6) Steering outside track driving force F to ;

[0196] S4. The control unit controls the drive motor to output the calculated inner track driving force F based on the steering force. tiand 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;

[0197] 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 .

[0198] In the steering control method of the special vehicle all-wheel drive multi-wheel and tracked composite walking system of the present invention

[0199] 1. Track turning radius and equivalent track rotation axis position:

[0200] Track turning radius and equivalent track rotation axis position relative to the steering angle δ of the outer wheel of the first axle o1 Steering angle δ on the inner side of the bridge i1 The geometric relationship between them is as follows:

[0201] (1) Steering angle δ of the outer side of the bridge o1 Geometric relations that conform to the formula:

[0202]

[0203] According to equation (1) above, we get:

[0204]

[0205] (2) Steering angle δ on the inner side of the bridge i1 Geometric relations that conform to the formula:

[0206]

[0207] (3) Based on the steering angle δ o1 With δ i1 From the geometric relationships, the turning radius R of the track can be obtained, that is:

[0208]

[0209] (4) Substitute R into the formula to obtain the distance between the equivalent track pivot position and the first axle, i.e.:

[0210]

[0211] 2. Wheel steering angles of the second and third axles:

[0212] (1) Steering angle δ of the outer wheel of the second axle o2 Geometric relations that conform to the formula:

[0213]

[0214] Therefore, the steering angle δ of the outer wheel of the second axle is obtained. o2 :

[0215]

[0216] (2) Steering angle δ of the inner wheel of the second axle i2 Geometric relations that conform to the formula:

[0217]

[0218] Therefore, the steering angle δ of the inner wheel of the second axle is obtained. i2 :

[0219]

[0220] (3) Steering angle δ of the outer wheel of the three-axle steering wheel o3 Geometric relations that conform to the formula:

[0221]

[0222] Therefore, the steering angle δ of the outer wheel of the three-axle steering wheel is obtained. o3 :

[0223]

[0224] (4) Steering angle δ of the inner wheel of the three-axle steering wheel i3 Geometric relations that conform to the formula:

[0225]

[0226] Therefore, the steering angle δ of the inner wheel of the three-axle steering wheel is obtained. i3 :

[0227]

[0228] 3. Wheel turning radius:

[0229] according to Figure 2 The geometric relationships shown can be used to obtain:

[0230] (1) The turning radius R of the outer wheel of the axle is expressed as the turning radius R of the track. o1 :

[0231]

[0232] (2) The turning radius R of the inner wheel of the axle, expressed as the track turning radius R. i1 :

[0233]

[0234] (3) The turning radius R of the outer wheel of the second axle, expressed as the track turning radius R. o2 :

[0235]

[0236] (4) The turning radius R of the inner wheel of the second axle, expressed as the track turning radius R. i2 :

[0237]

[0238] (5) The turning radius R of the outer wheel of the three-axle steering wheel, expressed as the track turning radius R. o3 :

[0239]

[0240] (6) The turning radius R of the inner wheel of the three-axle steering wheel, expressed as the track turning radius R. i3 :

[0241]

[0242] 4. Lateral force during wheel steering:

[0243] Assuming that the steering lateral force of the wheels is proportional to the axle load, the proportionality coefficient is related to the vehicle's steering state and remains consistent under the same vehicle steering state. The steering lateral force of the wheels on each of the first, second, and third axles is related to the load G on the first axle. w1 Second bridge load G w2 Three-bridge load G w3 The relationship between the lateral force coefficient λ and the lateral force coefficient is as follows:

[0244] (1) Lateral force of the wheels of the first axle during steering

[0245]

[0246] (2) Lateral force of the second axle wheels during steering

[0247]

[0248] (3) Lateral steering force of the three-axle wheels:

[0249]

[0250] 5. Driving resistance:

[0251] 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 can be obtained from tests on different road surfaces), that is:

[0252] The driving resistance of a single wheel is transmitted through the load G of the axle. w1 Second bridge load G w2 Three-bridge load G w3 The following can be obtained from the drag coefficient f:

[0253] (1) Wheel resistance of the first axle:

[0254]

[0255] (2) Resistance of the second axle wheels:

[0256]

[0257] (3) Resistance of the three-axle wheels:

[0258]

[0259] The running resistance of a single track is transmitted through the track's normal load G. t The following can be obtained from the drag coefficient f:

[0260]

[0261] 6. Track steering resistance:

[0262] 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 drag coefficient μ:

[0263]

[0264] 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;

[0265] 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:

[0266]

[0267] 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 The turning resistance per unit length of the grounding segment is proportional to its normal load per unit length p, and the proportionality coefficient remains μ.

[0268]

[0269] The action is applied to the ground contact sections of both tracks, with the equivalent length L of the front section of the track rotation axis. ω1 :

[0270]

[0271] Steering equivalent resistance F ts1 It can be expressed by the following formula:

[0272]

[0273] Similarly, the force acting on the ground contact sections of both tracks is equivalent to the length L of the rear section of the track rotation axis. ω2 :

[0274]

[0275] Steering equivalent resistance F ts2 It can be expressed by the following formula:

[0276]

[0277] Since the vehicle rotates around point O, F ts1 With F ts2 The direction of their effect is exactly the opposite.

[0278] The steering resistance coefficient μ is calculated using formula (8):

[0279]

[0280] Where μ max This is the maximum steering resistance coefficient on the road surface, obtained from tests on different road surfaces.

[0281] 7. Driving force of the inner and outer tracks

[0282] When a vehicle turns while traveling at low and constant speed, ignoring the influence of lateral acceleration, the balance relationship between force and torque is satisfied, as shown in equations (35), (36), and (37), which are the balance equations of force in the x-direction, force in the y-direction, and torque in the z-direction about point o in the Cartesian coordinate system:

[0283]

[0284]

[0285]

[0286] In the equation:

[0287] F so1 —The driving force of the outer wheel of the axle is as follows:

[0288] The torque r represents the torque of the outer wheel when the axle is turned. r1 Let be the rolling radius of a bridge wheel.

[0289] F si1 —The driving force for the inner wheels of the steering wheel on the first axle is of the following magnitude.

[0290] T wi1 r is the torque of the inner wheel when the axle is turned. r1 Let be the rolling radius of a bridge wheel.

[0291] F so2 —The driving force of the outer wheel of the second axle steering is of the following magnitude.

[0292] T wo2 The torque of the outer wheel when the second axle is turned is r. r2 The rolling radius of the second axle wheels.

[0293] F si2 —The driving force of the inner wheel of the second axle is [value missing].

[0294] T wi2 r is the torque of the inner wheel when the second axle is turned. r2 The rolling radius of the second axle wheels.

[0295] F so3 —The driving force of the outer wheels of the three-axle steering system is as follows: T wo3 For the torque of the outer wheel of the three-axle steering system, r r3 The rolling radius of the three-axle wheels.

[0296] F si3 —The driving force of the inner wheel of the three-axle steering wheel is of the following magnitude.

[0297] T wi3 r is the torque of the inner wheel of the three-axle steering system. r3 The rolling radius of the three-axle wheels.

[0298] F to —The driving force for steering the outer track.

[0299] F ti —The driving force for steering the inner track.

[0300] Substituting equations (23), (24), and (25) into equation (36):

[0301]

[0302] Let equation (38) be...

[0303]

[0304] G′ w =G w1 (cosδ o1 +cosδ i1 )+G w2 (cosδ o2 +cosδ i2 )+G w3 (cosδ o3 +cosδ i3 Equation (40)

[0305] Solving equation (38), we get:

[0306]

[0307] then:

[0308]

[0309]

[0310]

[0311] Rearranging equations (35) and (37), we get:

[0312]

[0313]

[0314] Let the relation on the right side of equations (45) and (46) be:

[0315]

[0316]

[0317] Equations (45) and (46) can be simplified to the following system of equations:

[0318]

[0319] Solving the system of equations, we get:

[0320]

[0321]

[0322] 8. Track drive force control during reverse movement:

[0323] The 6x6 all-wheel drive multi-wheel steering and tracked composite walking system, and the steering force relationship during reverse movement, such as... Figure 4 As shown. 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 .

[0324] The control method of this invention calculates the steering angle of each axle wheel and the driving force F of the inner and outer tracks during steering. ti F to The calculations enable real-time control of the steering angle of each axle wheel and the driving force F of the inner and outer tracks during steering. ti F to The size of the value determines the optimal steering angle of each axle wheel and the inner and outer track driving force F during vehicle steering. ti F to This ensures that the steering torque of the wheels and tracks is consistent with the load ratio, preventing the wheels from dragging the tracks or the tracks from dragging the wheels, thereby reducing the additional load on the structural components and minimizing the wear of both the wheels and tracks.

[0325] The present invention has been described above 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 using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution to other situations without modification, are all within the protection scope of the present invention.

Claims

1. A steering control method for a special vehicle's all-wheel drive multi-wheel and tracked composite walking system, characterized in that: The control steps of the steering control method for the special vehicle all-wheel drive multi-wheel and tracked composite walking system are as follows: S1. Special vehicles include single-axle, double-axle, and triple-axle vehicles. The all-wheel drive multi-wheel and tracked composite walking system includes multiple sensors, which measure and acquire the following parameters: (1) Steering angle of the outer wheel of the bridge , (2) Steering angle of the inner wheel of the first bridge , (3) Load on a bridge , (4) Load of the second bridge , (5) Load of the three bridges , (6) Track normal load , (7) Steering torque output of inner and outer wheels of the axle , , (8) Output torque of the inner and outer wheels of the second axle steering wheel , , (9) Output torque of inner and outer wheels of three-axle steering , ; S2. The following parameters shall be determined during the design of special vehicles: (1) The distance between the intersection of the extended lines of the left and right main pin centerlines of the bridge and the ground. , (2) Kingpin offset distance on the wheel contact surface , (3) Track center distance , (4) The distance between the bridge and the line connecting the centers of the tracks on both sides , (5) The distance between the first and second bridges , (6) The distance between the first bridge and the third bridge , (7) Ground contact length of one side of the track ; S3. The control unit calculates the following values: (1) Steering angle of the outer wheel of the second axle , (2) Steering angle of the inner wheel of the second axle , (3) Steering angle of the outer wheel of the three-axle steering wheel , (4) Steering angle of the inner wheel of the three-axle steering wheel , (5) Steering inside track driving force , (6) Steering outside track driving force ; 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 ; Track turning radius and equivalent track rotation axis position relative to the steering angle of the outer wheel of the first axle Steering angle of the inner side of the bridge The geometric relationship between them is as follows: (1) Steering angle of the outer side of the bridge Geometric relationships that conform to the formula: Equation (1) According to the above formula (1), we get: Equation (2) (2) Steering angle of the inner side of the bridge 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) The distance between the bridge and the equivalent track rotation axis.

2. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 1, characterized in that: (4) Substituting into the formula, we obtain the distance between the equivalent track pivot point and the first axle, i.e.: ； Equation (5).

3. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 2, characterized in that: (1) Steering angle of the outer wheel of the second axle Geometric relationships that conform to the formula: Equation (6) Therefore, the steering angle of the outer wheel of the second axle is obtained. : Equation (7) (2) Steering angle of the inner wheel of the second axle Geometric relationships that conform to the formula: Equation (8) Therefore, the steering angle of the inner wheel of the second axle is obtained. : Equation (9) (3) Steering angle of the outer wheel of the three-axle steering wheel Geometric relationships that conform to the formula: Equation (10) Therefore, the steering angle of the outer wheel of the three-axle steering wheel is obtained. : Equation (11) (4) Steering angle of the inner wheel of the three-axle steering wheel Geometric relationships that conform to the formula: Equation (12) Therefore, the steering angle of the inner wheel of the three-axle steering wheel is obtained. : Equation (13).

4. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 3, characterized in that: (1) Using the turning radius of the tracks This indicates the steering radius of the outer wheel of the axle. : Equation (14) (2) Using the turning radius of the tracks This indicates the steering radius of the inner wheel of the axle. : Equation (15) (3) Using the turning radius of the tracks The indicated steering radius of the outer wheel of the second axle steering system. : Equation (16) (4) Using the turning radius of the tracks The indicated steering radius of the inner wheel of the second axle steering wheel. : Equation (17) (5) Using the turning radius of the tracks The indicated steering radius of the outer wheel of the three-axle steering system. : Equation (18) (6) Using the turning radius of the tracks The indicated steering radius of the inner wheel of the three-axle steering wheel. : Equation (19).

5. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 4, characterized in that: The steering lateral force of the wheels on each of the first, second, and third axles and the load on the first axle. Second bridge load Three-bridge load and lateral force coefficient The relationship is: (1) Lateral force of the wheels of the first bridge during steering Equation (20) (2) Lateral force of the second axle wheels during steering Equation (21) (3) Lateral steering force of the three-axle wheels: Equation (22).

6. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 5, characterized in that: The driving resistance of a single wheel is transmitted through the load of an axle. Second bridge load Three-bridge load and driving drag coefficient Find: (1) Resistance of the wheels of the first bridge: Equation (23) (2) Resistance of the second axle wheels: Equation (24) (3) Resistance of the three-axle wheels: Equation (25) The running resistance of a single track is transmitted through the track's normal load. and driving drag coefficient Find: Equation (26).

7. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 6, characterized in that: Ground steering resistance and normal load Proportional to the steering drag coefficient, its proportionality coefficient is proportional to the steering drag coefficient. express: Equation (27) 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 (28) Given the normal load per unit length of the grounding segment, calculate the corresponding turning resistance per unit length of the grounding segment. The turning resistance per unit length of the grounding segment and its normal load per unit length. Proportional, the proportionality constant remains the same. : Equation (29) Acting on the ground contact sections of both tracks, equivalent to the length of the front section of the track rotation axis. : Equation (30) Steering equivalent resistance It can be expressed by the following formula: Equation (31) Similarly, the force acting on the ground contact sections of both tracks is equivalent to the length of the rear section of the track's rotation axis. : Equation (32) Steering equivalent resistance It can be expressed by the following formula: Equation (33) Due to the vehicle's detour Point rotation, therefore and The direction of their effect is exactly the opposite. Steering drag coefficient Calculate using formula (8): Equation (34) in This is the maximum steering resistance coefficient on the road surface, obtained from tests on different road surfaces.

8. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 7, characterized in that: When a vehicle turns while traveling at low and constant speed, ignoring the influence of lateral acceleration, the balance relationship between force and torque is satisfied, as shown in equations (35), (36), and (37) below. These equations are in the Cartesian coordinate system. Directional force, Directional force, rotation Pointed Directional moment balance equation: Equation (35) Equation (36) Equation (37).

9. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked composite walking system according to claim 8, characterized in that: Substituting equations (23), (24), and (25) into equation (36): Equation (38) Let equation (38) be used. Equation (39) Equation (40) Solving equation (38), we get: Equation (41) then: Equation (42) Equation (43) Equation (44) Rearranging equations (35) and (37), we get: Equation (45) Equation (46) Let the relation on the right side of equations (45) and (46) be: Equation (47) Equation (48) Equations (45) and (46) can be simplified to the following system of equations: Equation (49) Solving the system of equations, we get: Equation (50) Equation (51).

10. The steering control method for a special vehicle all-wheel drive multi-wheel and tracked 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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