Traveling device for tracked chassis, control method and tracked chassis system

Abstract

A traveling device and a control method for a tracked chassis, and a tracked chassis system. A traveling device for a tracked chassis includes a straight traveling controller configured to: receive an input longitudinal speed instruction; acquire a first and second drive wheel rotation speed, a lateral deflection angle of the tracked chassis in real time; determine a reference drive signal based on the longitudinal speed instruction and the first drive wheel rotation speed; generate a first correction value of the drive signal based on the lateral deflection angle; determine a total lateral displacement amount of the tracked chassis based on the lateral deflection angle and the second drive wheel rotation speed; generate a second correction value of the drive signal based on the total lateral displacement amount; take the one with a larger absolute value between the first correction value of the drive signal and the second correction value of the drive signal as a drive signal correction value; generate the first and second drive signals based on the reference drive signal and the drive signal correction value; and control the opening degree of the first and second electric proportional valves based on the first and second drive signals.

Description

Technical Field

[0001] This application relates to a walking device and control method for a tracked chassis, and also to a tracked chassis system including such a walking device. Background Technology

[0002] In the fields of construction and agricultural machinery vehicles, tracked chassis are widely used due to their advantages such as high reliability, strong adaptability, and simple operation. For certain working conditions of these vehicles, it is required that they can move forward or backward in a straight line at a stable speed while onboard; otherwise, the quality and efficiency of onboard operations cannot be met. Traditionally, construction and agricultural machinery vehicles control straight-line movement by having the driver control the vehicle's steering. For example, if the vehicle deviates to the left, the driver turns right to correct the vehicle's posture. This method of controlling straight-line movement has drawbacks. On the one hand, it requires the driver to manually control the vehicle in real time during operation, leading to high labor intensity and issues with precision and stability in manual operation. On the other hand, the driver needs to simultaneously control both onboard operations and offboard movement, resulting in low work efficiency. Summary of the Invention

[0003] The purpose of this application is to provide an improved solution for the linear travel control of tracked chassis.

[0004] Therefore, in one aspect, this application provides a traveling device for a tracked chassis, the tracked chassis including tracks driven by a first drive wheel and a second drive wheel respectively, the traveling device including a linear travel controller and a travel drive system;

[0005] The walking drive system includes: a hydraulic pump; a first motor for driving the first drive wheel to rotate and a second motor for driving the second drive wheel to rotate; a first closed circuit for transmitting hydraulic oil between the hydraulic pump and the first motor and a second closed circuit for transmitting hydraulic oil between the hydraulic pump and the second motor; a first electro-proportional valve for controlling the flow rate of the first closed circuit; and a second electro-proportional valve for controlling the flow rate of the second closed circuit.

[0006] The linear motion controller is configured to:

[0007] Receive input longitudinal speed commands;

[0008] Real-time acquisition of the first drive wheel speed, the second drive wheel speed, and the lateral deflection angle of the tracked chassis;

[0009] The reference drive signal is determined based on the longitudinal speed command and the rotational speed of the first drive wheel;

[0010] The first correction value of the drive signal is generated based on the lateral deflection angle;

[0011] The total lateral misalignment of the tracked chassis is determined based on the lateral deflection angle and the rotational speed of the second drive wheel;

[0012] A second correction value for the driving signal is generated based on the total lateral misalignment.

[0013] The larger of the absolute values ​​of the first and second correction values ​​of the drive signal is taken as the drive signal correction value.

[0014] A first drive signal and a second drive signal are generated based on a reference drive signal and a drive signal correction value; and

[0015] The opening degree of the first electro-proportional valve is controlled based on the first drive signal, and the opening degree of the second electro-proportional valve is controlled based on the second drive signal.

[0016] In one implementation, the process of determining the total lateral misalignment of the tracked chassis includes:

[0017] The lateral misalignment speed of the tracked chassis is obtained by multiplying the tangent of the lateral deflection angle with the travel speed of the tracked chassis based on the rotation speed of the second drive wheel, and the total lateral misalignment is obtained by integrating the lateral misalignment speed over time.

[0018] In one embodiment, the first driving signal is a reference driving signal, and the second driving signal is the reference driving signal plus a driving signal correction value.

[0019] In one embodiment, the first driving signal is the reference driving signal minus (k1 × driving signal correction value), and the second driving signal is the reference driving signal plus (k2 × driving signal correction value), where k1 and k2 are correction coefficients.

[0020] In one implementation, the values ​​of k1 and k2 are both in the range of 0 to 1.

[0021] In one implementation, k1+k2=1; for example, one of k1 and k2 is 0 and the other is 1, or both k1 and k2 are 0.5.

[0022] In one implementation, 1 <k1+k2<1.5。

[0023] In one implementation, k1 <k2。

[0024] In one embodiment, the linear motion controller is configured with a deflection angle threshold, and a first correction value for the drive signal is generated only when the lateral deflection angle is greater than the deflection angle threshold.

[0025] In one embodiment, the linear motion controller is configured with an offset total threshold, and a second correction value for the drive signal is generated only when the total lateral misalignment exceeds the offset total threshold.

[0026] In one embodiment, the hydraulic pump is a constant-pressure variable pump; the walking drive system further includes a first compensation valve and a second compensation valve, the inlets of the first compensation valve and the second compensation valve are respectively connected to the output port of the hydraulic pump, the outlet of the first compensation valve is connected to the inlet of a first electro-proportional valve, and the first compensation valve is configured to adjust its opening based on the system pressure feedback of a first closed loop, the outlet of the second compensation valve is connected to the inlet of a second electro-proportional valve, and the second compensation valve is configured to adjust its opening based on the system pressure feedback of a second closed loop.

[0027] This application further provides a linear travel control method for a tracked chassis, the tracked chassis comprising: tracks driven by a first drive wheel and a second drive wheel respectively; a hydraulic pump; a first motor for driving the first drive wheel and a second motor for driving the second drive wheel; a first closed-loop circuit for transmitting hydraulic oil between the hydraulic pump and the first motor and a second closed-loop circuit for transmitting hydraulic oil between the hydraulic pump and the second motor; a first electro-proportional valve for controlling the flow rate of the first closed-loop circuit; and a second electro-proportional valve for controlling the flow rate of the second closed-loop circuit.

[0028] The linear motion control method includes:

[0029] Receive input longitudinal speed commands;

[0030] Real-time acquisition of the first drive wheel speed, the second drive wheel speed, and the lateral deflection angle of the tracked chassis;

[0031] The reference drive signal is determined based on the longitudinal speed command and the rotational speed of the first drive wheel;

[0032] The first correction value of the drive signal is generated based on the lateral deflection angle;

[0033] The total lateral misalignment of the tracked chassis is determined based on the lateral deflection angle and the rotational speed of the second drive wheel;

[0034] A second correction value for the driving signal is generated based on the total lateral misalignment.

[0035] The larger of the absolute values ​​of the first and second correction values ​​of the drive signal is taken as the drive signal correction value.

[0036] A first drive signal and a second drive signal are generated based on a reference drive signal and a drive signal correction value; and

[0037] The opening degree of the first electro-proportional valve is controlled based on the first drive signal, and the opening degree of the second electro-proportional valve is controlled based on the second drive signal.

[0038] The various features of the walking device of this application are also applicable to the linear walking control method of this application.

[0039] This application further provides a tracked chassis system, including:

[0040] A tracked chassis, the tracked chassis comprising: a first drive wheel and a second drive wheel, and tracks driven by the first drive wheel and the second drive wheel respectively; and

[0041] The walking device of this application is used to drive the first drive wheel and the second drive wheel to rotate.

[0042] The tracked chassis traveling device according to this application is equipped with a traveling correction mechanism and has a fully autonomous straight-line traveling control function, requiring no human intervention and greatly reducing the driver's workload. Furthermore, the traveling device has high control precision and good control stability. In addition, the traveling device employs multiple controllers to adapt to various road conditions, ensuring that the vehicle's speed and attitude are simultaneously well controlled. Attached Figure Description

[0043] The foregoing and other aspects of this application will be more fully understood and appreciated through the following detailed description with reference to the accompanying drawings, in which:

[0044] Figure 1 This is a schematic diagram of an exemplary tracked chassis traveling device of this application;

[0045] Figure 2 This is a schematic diagram of a tracked chassis that can adopt the walking device of this application;

[0046] Figure 3 This is a flowchart of an exemplary walking device control method of this application. Detailed Implementation

[0047] This application generally relates to tracked chassis systems for engineering machinery vehicles, agricultural machinery vehicles, etc. These vehicles typically consist of an upper vehicle and an undercarriage. The upper vehicle is mounted on the undercarriage and can perform various tasks. The undercarriage contains the tracked chassis for enabling the vehicle to move.

[0048] The tracked chassis system of this application includes a tracked chassis and a traveling device. The tracked chassis travels by the traveling device driving the tracks. When these vehicles are performing certain onboard operations, it is required that they can move in a straight line after dismounting. This application provides a traveling device for engineering machinery vehicles, agricultural machinery vehicles, etc., capable of autonomously achieving straight-line movement without requiring real-time steering correction by the driver.

[0049] An exemplary configuration of the walking device of this application is as follows: Figure 1 The walking device is shown in the image. It uses a hydraulic motor as its drive element.

[0050] See Figure 1The walking device includes a linear travel controller 1 and a hydraulic travel drive system 2. The linear travel controller 1 can control the travel drive system 2 to achieve linear travel of the vehicle.

[0051] The walking drive system 2 has a single hydraulic pump 12 as its power source. The hydraulic pump 12 is a constant-pressure variable pump, capable of outputting a constant hydraulic pressure. The hydraulic pump 12 supplies hydraulic oil to fixed-displacement hydraulic motors 17 and 18 to drive the motors 17 and 18 (which can be referred to as the first motor and the second motor, respectively) to rotate. Motors 17 and 18 respectively drive the drive wheels 19 and 20 (which can be referred to as the first drive wheel and the second drive wheel, respectively) of the tracked chassis to rotate.

[0052] The hydraulic oil output from hydraulic pump 12 to motors 17 and 18 is controlled by electro-proportional valves 13 and 14 (which can be referred to as the first electro-proportional valve and the second electro-proportional valve, respectively).

[0053] Proportional valves 13 and 14 have the same structure. Each proportional valve 13 and 14 has an inlet port (P port), a return port (T port), a first working port (A port), and a second working port (B port), and each has three valve positions. In the neutral valve position, ports P, T, A, and B are all cut off. In the first working valve position, ports P and A are connected, and ports T and B are connected. In the second working valve position, ports P and B are connected, and ports T and A are connected.

[0054] Ports A and B of proportional valve 13 are connected to the first and second oil ports of motor 17, respectively. Ports A and B of proportional valve 14 are connected to the first and second oil ports of motor 18, respectively.

[0055] The valve positions of proportional valves 13 and 14, and their opening degree in the working position, are controlled by the drive current applied to the electromagnets on their respective control terminals.

[0056] The output port of hydraulic pump 12 is branched to the inlet of pressure compensation valves 15 and 16 (which can be referred to as the first compensation valve and the second compensation valve, respectively). The outlet of pressure compensation valve 15 is connected to the P port of proportional valve 13, and the outlet of pressure compensation valve 16 is connected to the P port of proportional valve 14.

[0057] The input port of hydraulic pump 12 is connected to the oil tank. Furthermore, the T-ports of proportional valves 13 and 14 are both connected to the input port of hydraulic pump 12.

[0058] In this way, a first closed hydraulic circuit is formed between the hydraulic pump 12 and the motor 17, and a second closed hydraulic circuit is also formed between the hydraulic pump 12 and the motor 18.

[0059] The oil pressure at the first control end of the pressure compensation valve 15 is taken from the output end of the pressure compensation valve 15, and the oil pressure at the second control end is taken from the higher of the two oil pressures (first oil port oil pressure and second oil port oil pressure) on both sides of the motor 17 via the shuttle valve, namely the load oil pressure.

[0060] The oil pressure at the first control end of the pressure compensation valve 16 is taken from the output end of the pressure compensation valve 16, and the oil pressure at the second control end is taken from the higher of the two oil pressures (first oil port oil pressure and second oil port oil pressure) on both sides of the motor 18 via the shuttle valve, namely the load oil pressure.

[0061] When both proportional valves 13 and 14 are in the neutral position, proportional valves 13 and 14 cut off the hydraulic supply from hydraulic pump 12 to motors 17 and 18. Motors 17 and 18 do not rotate, so the vehicle does not move.

[0062] When proportional valves 13 and 14 are both in their first working positions, hydraulic pump 12 supplies hydraulic oil to the first ports of motors 17 and 18, driving motors 17 and 18 to rotate in the forward direction. Motors 17 and 18 drive their respective drive wheels 19 and 20 to rotate in the forward direction, and drive wheels 19 and 20 drive their respective tracks to move in a first direction (e.g., forward). The hydraulic oil in motors 17 and 18 returns to the input port of hydraulic pump 12 through their respective second ports.

[0063] When proportional valves 13 and 14 are both in the second working position, hydraulic pump 12 supplies hydraulic oil to the second ports of motors 17 and 18, driving motors 17 and 18 to rotate in opposite directions. Motors 17 and 18 drive their respective drive wheels 19 and 20 to rotate in opposite directions, and drive wheels 19 and 20 drive their respective tracks to travel in a second direction (e.g., backward). The hydraulic oil in motors 17 and 18 returns to the input port of hydraulic pump 12 through their respective first ports.

[0064] When the system pressure in the two closed hydraulic circuits is unbalanced, the pressure is fed back to the second control end of the pressure compensation valves 15 and 16 through their respective shuttle valves. The flow area and output pressure of the pressure compensation valves 15 and 16 are adjusted to balance the system pressure in the two closed hydraulic circuits. This maintains the transmission of roughly balanced driving force from the motors 17 and 18 to the drive wheels 19 and 20, which helps the tracked chassis to travel in a straight line.

[0065] The output shaft of motor 17 is connected to the shaft of drive wheel 19. The output shaft of motor 17 or the shaft of drive wheel 19 is equipped with a rotary encoder (which may be called a first rotary encoder or a first speed sensor) 21 to detect the rotational speed of motor 17 and drive wheel 19.

[0066] The output shaft of motor 18 is connected to the shaft of drive wheel 20. The output shaft of motor 18 or the shaft of drive wheel 19 is equipped with a rotary encoder (which may be called a second rotary encoder or a second speed sensor) 22 for detecting the rotational speed of motor 18 and drive wheel 20.

[0067] In addition, the walking drive system 2 also includes a gyroscope (deflection angle sensor) 23 for detecting the lateral (left and right) deflection angle of the tracked chassis.

[0068] When the driver inputs a signal to move the vehicle (forward or backward), the driving force is transmitted from motors 18 and 19 to drive wheels 21 and 22 respectively. Drive wheels 21 and 22 drive the tracks, and the two tracks together drive the vehicle. Ideally, if motors 21 and 22 rotate at the same speed, the vehicle can move in a straight line; if the speeds are different, the vehicle will veer. However, because the ground contact conditions of the two tracks are not the same, and the mechanical structures on both sides are not completely identical, the same motor speed will produce different track speeds, causing the vehicle to veer laterally at the same motor speed. Therefore, to ensure the vehicle moves in a straight line, the vehicle's attitude must be collected in real time, and the proportional valve opening must be adjusted in a closed loop.

[0069] The linear motion controller 1 is configured to receive a travel command signal 3 input by the driver through the vehicle's command input interface. The command input interface can be a handle, pedal, human-machine interface touch screen, etc. The driver's operation of the command input interface can generate a travel command signal 3 in the form of current, voltage, or digital signals. The linear motion controller 1 also receives the actual rotational speed signals of the drive wheels 19 and 20 from the rotary encoders 21 and 22, and the actual lateral deflection angle of the tracked chassis from the gyroscope 23.

[0070] The linear motion controller 1 is also connected to the control terminals on both sides of the proportional valves 13 and 14, and is used to output drive signals to the control terminals on both sides of the proportional valves 13 and 14.

[0071] The linear motion controller 1 includes: a command generator 4, a speed controller 5, a multiplier 6, an integrator 7, a lateral offset controller 8, an attitude angle controller 9, a selector 10, and an adder 11.

[0072] The instruction generator 4 is configured to receive a driving instruction signal 3 input by the driver. The driving instruction signal 3 contains the desired longitudinal (forward or backward) direction of vehicle movement and longitudinal speed information. The instruction generator 4 processes the driving instruction signal 3 to generate a longitudinal speed instruction (the desired longitudinal driving speed) and sends the longitudinal speed instruction to the speed controller 5.

[0073] The speed controller 5 receives the longitudinal speed command from the command generator 4 and the actual rotational speed of the drive wheel 19 fed back by the rotary encoder 21. The speed controller 5 compares the longitudinal speed command with the actual rotational speed calculated based on the actual rotational speed of the drive wheel 19, generates a reference drive signal Sa that is positively correlated with the comparison result, and sends the reference drive signal Sa as the first drive signal to the corresponding control terminal of the proportional valve 13. At the corresponding control terminal of the proportional valve 13, the electromagnet generates a drive current, controlling the valve position and opening degree of the proportional valve 13. It can be understood that, depending on whether the travel command signal 3 indicates that the vehicle is moving forward or backward, the first drive signal is sent to the corresponding control terminal on either side of the proportional valve 13.

[0074] The speed controller 5 also sends the reference drive signal Sa to the adder 11.

[0075] The gyroscope 23 detects the lateral deflection angle α of the tracked chassis in real time, and the attitude angle controller 9 receives the actual deflection angle α detected by the gyroscope 23. The attitude angle controller 9 stores or receives a deflection angle threshold Δα. When the actual deflection angle α is greater than the deflection angle threshold Δα, the attitude angle controller 9 generates a first correction value ΔS1 of the drive signal that is positively correlated (e.g., proportional) to the actual deflection angle α and the physical dimensions of the tracked chassis, and sends the first correction value ΔS1 of the drive signal to the selector 10. If the actual deflection angle α is less than or equal to the deflection angle threshold Δα, the first correction value ΔS1 of the drive signal is set to zero.

[0076] The relationship between the first correction value ΔS1 and the actual deflection angle α can be simply expressed by a linear expression. For example, a coefficient c1 can be determined based on the physical dimensions of the tracked chassis, and ΔS1 = c1 × α. Alternatively, a lookup table containing the corresponding values ​​between the first correction value ΔS1 and the actual deflection angle α can be established, through which the first correction value ΔS1 corresponding to the actual deflection angle α can be found.

[0077] On the other hand, multiplier 6 receives the actual deflection angle α detected by gyroscope 23 and the actual rotational speed signal of drive wheel 20 fed back by rotary encoder 22. It multiplies the tangent of the actual deflection angle α with the vehicle (tracked chassis) travel speed signal obtained based on the actual rotational speed signal of drive wheel 20 to obtain the lateral misalignment speed of tracked chassis, and sends the lateral misalignment speed to integrator 7. It can be understood that the travel speed here can be simply obtained by multiplying the rotational speed of drive wheel 20 by the distance from the center axis of drive wheel 20 to the ground. Alternatively, the travel speed can be obtained by multiplying the average rotational speed of drive wheels 19 and 20 by the distance from their center axes to the ground.

[0078] In integrator 7, the lateral misalignment velocity is integrated over time to obtain the total lateral misalignment Y, and the total lateral misalignment Y is sent to the lateral offset controller 8.

[0079] Lateral offset controller 8 stores or receives a lateral misalignment total threshold ΔY. When the total lateral misalignment Y is greater than the lateral misalignment total threshold ΔY, lateral offset controller 8 generates a second correction value ΔS2 of the drive signal that is positively correlated (e.g., proportional) to the total lateral misalignment Y, and sends the second correction value ΔS2 of the drive signal to selector 10. If the total lateral misalignment Y is less than or equal to the lateral misalignment total threshold ΔY, the total lateral misalignment Y is set to zero.

[0080] The relationship between the second correction value ΔS2 and the total lateral misalignment Y can be simply expressed by a linear expression. For example, a coefficient c2 can be determined based on the physical dimensions of the tracked chassis, ΔS2 = c2 × Y. Alternatively, a lookup table containing the corresponding values ​​between the second correction value ΔS2 and the total lateral misalignment Y can be established, through which the second correction value ΔS2 corresponding to the total lateral misalignment Y can be found.

[0081] The values ​​of the first correction value ΔS1 and the second correction value ΔS2 may be positive or negative. When the output value of the rotary encoder 22 is greater than the output value of the rotary encoder 21, the first correction value ΔS1 and the second correction value ΔS2 take negative values; when the output value of the rotary encoder 22 is less than the output value of the rotary encoder 21, the first correction value ΔS1 and the second correction value ΔS2 take positive values.

[0082] In selector 10, the larger of the absolute values ​​of the first correction value ΔS1 and the second correction value ΔS2 is selected as the drive signal correction value ΔS (which may be positive or negative), and the drive signal correction value ΔS is sent to adder 11. In adder 11, the reference drive signal Sa is added to the drive signal correction value ΔS to obtain the corrected drive signal Sb, and the corrected drive signal Sb is sent as the second drive signal to the control terminal of proportional valve 14. At the control terminal of proportional valve 14, the electromagnet generates a drive current to control the valve position and opening degree of proportional valve 14. It can be understood that, similarly, depending on whether the travel command signal 3 indicates that the vehicle is moving forward or backward, the second drive signal is sent to the corresponding control terminal on both sides of proportional valve 13.

[0083] Through the above control method, the linear travel controller 1 sends the first drive signal (reference drive signal Sa) to the control terminal of the proportional valve 13 and sends the second drive signal (drive signal with correction Sb=Sa+ΔS) to the control terminal of the proportional valve 14. Thus, by controlling the opening of the proportional valves 13 and 14 with different drive signals, the hydraulic oil flow from the hydraulic pump 12 to the motor 18 is corrected, the rotational speed of the drive wheel 20 is corrected, and the direction of the tracked chassis is corrected in real time, so that the tracked chassis can keep moving forward or backward in a straight line at a relatively constant speed.

[0084] It should be noted that in software, various data mentioned above are usually calculated in the form of normalized dimensionless data during calculation, so there is no need to consider their actual dimensions.

[0085] In the straight-line walking controller 1, the instruction generator 4, the speed controller 5, the multiplier 6, the integrator 7, the lateral offset controller 8, the attitude angle controller 9, the selector 10, and the adder 11 are implemented in the form of software modules or in the form of software modules plus hardware.

[0086] Furthermore, the first drive signal can be taken as (Sa - k1×ΔS) and sent to the control end of the proportional valve 13, and the second drive signal can be taken as (Sa + k2×ΔS) and sent to the control end of the proportional valve 14, which can also correct the direction of the crawler chassis in real time and keep the crawler chassis moving forward or backward in a straight line approximately constantly. k1 and k2 are correction factors, and the preferred value ranges are both between 0 and 1. k1 and k2 can be equal. Or, k1 and k2 can be unequal. Preferably, k1 < k2, which can avoid excessive reciprocating swing of the traveling direction of the crawler belt pulley.

[0087] Generally, k1 + k2 = 1 can be taken. For example, simplest, one of k1 and k2 is taken as 0 and the other is taken as 1; or both k1 and k2 are 0.5, in which case only the rotational speed of one of the drive wheels needs to be adjusted. Or, 1 < k1 + k2 < 1.5 can be taken, which can achieve compensation in the reverse direction of the deflection direction of the crawler chassis by correcting the rotational speed of the drive wheels and is easier to quickly achieve the expected vehicle traveling direction.

[0088] The setting of the deflection angle threshold Δα and the total lateral misalignment threshold ΔY can avoid the straight-line walking controller 1 from frequently correcting the rotational speed of the drive wheels and improve the stability of control. One or both of the deflection angle threshold Δα and the total lateral misalignment threshold ΔY can be adjustable. [[ID=​​​​​​​​​​​​​The described walking device, or similar walking devices for tracked chassis.

[0091] The linear travel control method of this application is applicable to a tracked chassis that includes a pair of drive wheels, referred to as the first drive wheel and the second drive wheel, and includes the hydraulic travel drive system 2 described above.

[0092] An exemplary process of the linear walking control method of this application is as follows: Figure 3 It is displayed in the middle.

[0093] See Figure 3 In step S1, a longitudinal speed command (the vehicle's desired travel speed by the driver) is received.

[0094] Next, in step S2, the rotational speed of the first drive wheel, the rotational speed of the second drive wheel, and the lateral deflection angle of the tracked chassis are acquired in real time.

[0095] Next, in step S3, a reference drive signal is determined based on the longitudinal speed command and the rotational speed of the first drive wheel. After step S3 is completed, proceed to step S5.

[0096] Step S4 is executed in parallel with step S3.

[0097] Step S4 includes the following sub-steps:

[0098] In sub-step S41, a first correction value for the drive signal is generated based on the lateral deflection angle, and then the process proceeds to sub-step S45.

[0099] Executed in parallel with sub-step S41: In sub-step S42, the lateral misalignment speed of the tracked chassis is determined based on the lateral deflection angle and the rotational speed of the second drive wheel; in sub-step S43, the lateral misalignment speed is accumulated to obtain the total lateral misalignment; in sub-step S44, a second correction value for the drive signal is generated based on the total lateral misalignment, and then proceeds to sub-step S45.

[0100] In sub-step S45, the larger of the absolute values ​​of the first and second correction values ​​of the drive signal is taken as the drive signal correction value. After sub-step S45 is completed, proceed to step S5.

[0101] In step S5, a first drive signal is generated based at least on a reference drive signal, and a second drive signal is generated based on the reference drive signal and a drive signal correction value.

[0102] Next, in step S6, a first drive signal is sent to a first proportional valve, and a second drive signal is sent to a second proportional valve. The first proportional valve is used to control the hydraulic pump to supply hydraulic oil to the first hydraulic motor that drives the first drive wheel, and the second proportional valve is used to control the hydraulic pump to supply hydraulic oil to the second hydraulic motor that drives the second drive wheel.

[0103] The implementation of the drive signal in the linear motion control method can be referred to the previous description of the motion device, especially the linear motion controller 1. Therefore, the relevant features described above for the motion device, especially the linear motion controller 1, can be incorporated into the linear motion control method, and will not be described again here.

[0104] The tracked chassis traveling device according to this application performs closed-loop control of the drive wheel speed by collecting the rotational speed and deflection information of the tracked chassis in real time, realizing a fully autonomous linear travel control function without human intervention, which greatly reduces the labor intensity of the driver.

[0105] Furthermore, in the closed-loop control, the feedback control signal (drive signal correction value) is determined based on both the lateral deflection angle (chassis angle deviation) and the total lateral misalignment (chassis lateral position deviation). Therefore, the walking device exhibits high control accuracy and good control stability. Specifically, compared to methods that only use the lateral deflection angle to correct the drive wheel speed, this application adds consideration to the vehicle speed (tracked chassis walking speed). At lower vehicle speeds, the vehicle's lateral misalignment mainly depends on the size of the lateral deflection angle. However, at higher vehicle speeds, the influence of vehicle speed on lateral misalignment increases, and even a small lateral deflection angle can lead to a large vehicle lateral misalignment. Because this application simultaneously considers both the lateral deflection angle and the total lateral misalignment, and takes the larger of the absolute values ​​of the drive signal correction values ​​determined based on these two factors, it can achieve high-precision and stable walking path control across various speed ranges.

[0106] In addition, the controller of the walking device uses a variety of detection signals (drive wheel speed sensor signal, yaw angle sensor) to adapt to various road conditions, ensuring that the vehicle's speed and attitude are well controlled at the same time.

[0107] While this application has been described herein with reference to specific embodiments, the scope of this application is not limited to the details shown. Various modifications may be made to these details without departing from the basic principles of this application.

Claims

1. A walking device for a tracked chassis, the tracked chassis comprising tracks driven by a first drive wheel (19) and a second drive wheel (20) respectively, the walking device comprising a linear travel controller (1) and a travel drive system (2). in, The walking drive system (2) includes: a hydraulic pump (12); a first motor (17) for driving the first drive wheel (19) to rotate and a second motor (18) for driving the second drive wheel (20) to rotate; a first closed circuit for transmitting hydraulic oil between the hydraulic pump (12) and the first motor (17) and a second closed circuit for transmitting hydraulic oil between the hydraulic pump (12) and the second motor (18); a first electro-proportional valve (13) for controlling the flow rate of the first closed circuit; and a second electro-proportional valve (14) for controlling the flow rate of the second closed circuit. The linear motion controller (1) is configured to: Receive input longitudinal speed commands; Real-time acquisition of the first drive wheel speed, the second drive wheel speed, and the lateral deflection angle of the tracked chassis; The reference drive signal is determined based on the longitudinal speed command and the rotational speed of the first drive wheel; The first correction value of the drive signal is generated based on the lateral deflection angle; The total lateral misalignment of the tracked chassis is determined based on the lateral deflection angle and the rotational speed of the second drive wheel; A second correction value for the driving signal is generated based on the total lateral misalignment. The larger of the absolute values ​​of the first and second correction values ​​of the drive signal is taken as the drive signal correction value. A first drive signal and a second drive signal are generated based on a reference drive signal and a drive signal correction value; and The opening degree of the first electro-proportional valve (13) is controlled based on the first drive signal, and the opening degree of the second electro-proportional valve (14) is controlled based on the second drive signal.

2. The walking device as described in claim 1, wherein, The process of determining the total lateral misalignment of a tracked chassis includes: The lateral misalignment speed of the tracked chassis is obtained by multiplying the tangent of the lateral deflection angle with the travel speed of the tracked chassis based on the rotation speed of the second drive wheel, and the total lateral misalignment is obtained by integrating the lateral misalignment speed over time.

3. The walking device as described in claim 1, wherein, The first drive signal is the reference drive signal, and the second drive signal is the reference drive signal plus a drive signal correction value.

4. The walking device as described in claim 1, wherein, The first drive signal is the reference drive signal minus (k1 × drive signal correction value), and the second drive signal is the reference drive signal plus (k2 × drive signal correction value), where k1 and k2 are correction coefficients.

5. The walking device as described in claim 4, wherein, The values ​​of k1 and k2 are both in the range of 0 to 1.

6. The walking device as described in claim 5, wherein, k1+k2=1.

7. The walking device as described in claim 6, wherein, One of k1 and k2 is 0 and the other is 1, or both k1 and k2 are 0.

5.

8. The walking device as described in claim 5, wherein, 1 <k1+k2<1.5。 9. The walking device as described in any one of claims 1-8, wherein, The linear walking controller (1) is configured with a deflection angle threshold, and a first correction value for the drive signal is generated only when the lateral deflection angle is greater than the deflection angle threshold.

10. The walking device as described in any one of claims 1-8, wherein, The linear walking controller (1) is configured with an offset total threshold, and a second correction value for the drive signal is generated only when the total lateral misalignment exceeds the offset total threshold.

11. The walking device as described in any one of claims 1-8, wherein, The hydraulic pump (12) is a constant pressure variable pump; The walking drive system (2) further includes a first compensation valve (15) and a second compensation valve (16). The inlets of the first compensation valve (15) and the second compensation valve (16) are respectively connected to the output port of the hydraulic pump (12). The outlet of the first compensation valve (15) is connected to the inlet of the first electro-proportional valve (13). The first compensation valve (15) is configured to adjust its opening based on the system pressure feedback of the first closed loop. The outlet of the second compensation valve (16) is connected to the inlet of the second electro-proportional valve (14). The second compensation valve (16) is configured to adjust its opening based on the system pressure feedback of the second closed loop.

12. A method for controlling linear travel on a tracked chassis, the tracked chassis comprising: Tracks driven by the first drive wheel (19) and the second drive wheel (20) respectively; Hydraulic pump (12); a first motor (17) for driving a first drive wheel (19) and a second motor (18) for driving a second drive wheel (20); a first closed circuit for transmitting hydraulic oil between the hydraulic pump (12) and the first motor (17) and a second closed circuit for transmitting hydraulic oil between the hydraulic pump (12) and the second motor (18); a first electro-proportional valve (13) for controlling the flow rate of the first closed circuit; and a second electro-proportional valve (14) for controlling the flow rate of the second closed circuit. The linear motion control method includes: Receive input longitudinal speed commands; Real-time acquisition of the first drive wheel speed, the second drive wheel speed, and the lateral deflection angle of the tracked chassis; The reference drive signal is determined based on the longitudinal speed command and the rotational speed of the first drive wheel; The first correction value of the drive signal is generated based on the lateral deflection angle; The total lateral misalignment of the tracked chassis is determined based on the lateral deflection angle and the rotational speed of the second drive wheel; A second correction value for the driving signal is generated based on the total lateral misalignment. The larger of the absolute values ​​of the first and second correction values ​​of the drive signal is taken as the drive signal correction value. A first drive signal and a second drive signal are generated based on a reference drive signal and a drive signal correction value; and The opening degree of the first electro-proportional valve (13) is controlled based on the first drive signal, and the opening degree of the second electro-proportional valve (14) is controlled based on the second drive signal.

13. A tracked chassis system, comprising: A tracked chassis, the tracked chassis comprising: a first drive wheel (19) and a second drive wheel (20), and tracks (25) driven by the first drive wheel (19) and the second drive wheel (20) respectively; and The walking device as described in any one of claims 1-11 is used to drive the first drive wheel (19) and the second drive wheel (20) to rotate.

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