Steering control method and device for four-wheel independent motor driven articulated vehicle and vehicle

Abstract

The invention discloses a four-wheel independent motor drive articulated vehicle steering control method and device and a vehicle, the four-wheel independent motor drive articulated vehicle steering control method comprises the following steps: detecting the current steering angle of a whole machine, the vehicle speed and the displacement direction and size of a valve core of a steering valve in real time; according to the current steering angle of the whole machine, the vehicle speed and the displacement direction and size of a valve element of a steering valve, a four-wheel differential auxiliary steering control signal is obtained through calculation, and the four-wheel differential auxiliary steering control signal is output according to a set control strategy and used for assisting steering of a hydraulic system. Therefore, unstable shaking of the whole machine during steering starting and steering stopping is improved, impact during steering stopping is reduced, steering energy consumption is reduced, and synchronization of hydraulic steering and differential auxiliary steering is kept.

Description

Technical Field

[0001] The present invention belongs to the technical field of engineering vehicles, and in particular relates to a steering control method, a device and a vehicle for an articulated vehicle driven by four independent motors. Background Art

[0002] In the prior art, large-tonnage articulated steering loaders use a front and rear four-wheel independent motor-driven reducer-driven walking solution, and generate electricity through a large-capacity battery or an engine-driven generator to power the four wheel motors to drive the walking. The steering system is a hydraulic flow amplification steering system. Since the vehicle itself and the load are very heavy (50t~300t), the motor-driven wheel differential assist hydraulic system steering is actively increased during steering. However, the following problems still exist during steering during the walking process: In the initial stage of steering start-up, the steering hydraulic cylinder action is not synchronized with the motor-driven wheel differential action, and the motor differential responds first. At this time, the cylinder control valve has not yet acted, and the cylinder is in a locked state. The steering cylinder is instantly pressed, and then the steering cylinder control valve is opened to make the cylinder move. Since the two actions are not synchronized, the steering of the whole vehicle will be unstable when starting, the steering shaking of the whole vehicle will be increased, the driving comfort will be reduced, and there will be certain energy loss and tire wear; or the motor drive wheel differential action is later than the steering cylinder action. At this time, the steering hydraulic system drags the motor drive wheel to rotate, the steering cylinder pressure rises rapidly, and then the motor drive wheel differential starts to assist the steering. At the moment of the motor drive wheel differential action, the steering of the whole machine will also be unstable and shake. Since the cab is high (2m~8m), the shaking will be magnified in the cab, reducing driving comfort, and there will also be certain energy loss and tire wear. The left and right steering limit positions are generally hard limit or rubber pad limit. When the differential assist steering reaches the left and right limit angles and then stops, the stopping impact will increase, the shaking of the whole vehicle will increase, and the impact on the hinge position will be greater. Long-term and multiple violent impacts will reduce the fatigue strength of the hinge position of the front and rear frames, affecting its long-term reliability. Summary of the invention

[0003] In order to address the deficiencies in the prior art, the present invention provides a steering control method, device and vehicle for a four-wheel independent motor driven articulated vehicle, which improves the unstable shaking of the whole machine during steering start and steering stop, reduces the impact during steering stop, reduces steering energy consumption, and reduces tire wear caused by the lack of synchronization between hydraulic steering and differential assisted steering.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: In a first aspect, a steering control method for a four-wheel independent motor driven articulated vehicle is provided, comprising: real-time detection of the current steering angle, vehicle speed, and valve core displacement direction and size of the whole machine; calculating a four-wheel differential auxiliary steering control signal according to the current steering angle, vehicle speed, and valve core displacement direction and size of the steering valve of the whole machine, and outputting the four-wheel differential auxiliary steering control signal according to a set control strategy, which is used to assist the steering of the hydraulic system, thereby improving the unstable shaking of the whole machine during steering start and steering stop, reducing the impact during steering stop, reducing steering energy consumption, and maintaining synchronization between hydraulic steering and differential auxiliary steering.

[0005] Furthermore, the vehicle adopts a load-sensitive pump steering system, the steering method is steering by a steering wheel and / or an electronically controlled steering handle, and the steering valve is a common steering valve or a flow amplification valve.

[0006] Furthermore, the four-wheel differential control signal is output according to the set control strategy, including: when the steering wheel or the electronic steering handle is moved, the main controller detects the current steering angle of the whole machine , when the steering angle satisfy: At the same time, the valve core of the steering valve moves, and the main controller detects whether the displacement direction d and displacement size Δt of the valve core of the steering valve are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed to assist the hydraulic system in steering. At the same time, the main controller detects the current steering angle of the whole machine in real time. ,when or When the main controller stops outputting the four-wheel differential auxiliary steering control signal, the steering continues by relying on the steering hydraulic system and the mass inertia of the whole machine until the steering wheel or the electronic steering handle stops steering or the main controller stops steering when detecting the limit angle signal of the articulation position angle sensor or the frame stops steering when hitting the limit device; wherein, Indicates a set angle value. Indicates the left and right steering limit angles of the vehicle. Indicates another set angle value.

[0007] Furthermore, the four-wheel differential control signal is output according to the set control strategy, and the steering angle is Not Available When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller detects the valve core displacement direction d and displacement size Δt of the steering valve, and determines whether the displacement direction d and displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops outputting the signal. When the signal is not 0, the next action is determined according to the detected steering system pressure p. When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller has no four-wheel differential auxiliary steering control signal output. When A-Δp≤p≤A, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed state, and then continues to detect the current steering angle of the whole machine. Rate of change ,when When it is not 0, the whole machine will turn and continue to turn. When it is equal to 0, the main controller outputs a four-wheel differential auxiliary steering control signal until the whole machine starts to turn; wherein A represents the high-pressure overflow pressure set by the steering system, and Δp represents a set pressure difference.

[0008] Furthermore, the vehicle adopts an electronically controlled pump steering system, the steering method is steering by a steering wheel and / or an electronically controlled steering handle, and the steering valve is a common steering valve or a flow amplification valve.

[0009] Furthermore, a four-wheel differential control signal is output according to a set control strategy, including: a main controller detects an angle sensor signal of a steering wheel or an electronically controlled steering handle; when the angle sensor electrical signal of the steering wheel or the electronically controlled steering handle is 0, the output flow of the electronically controlled pump is 0 or maintains a standby flow, and the entire machine has no steering action or the steering stops.

[0010] Furthermore, the four-wheel differential control signal is output according to the set control strategy, and it also includes: when the electrical signal of the angle sensor of the steering wheel or the electronically controlled steering handle is not 0, the main controller detects the current steering angle of the whole machine , when the steering angle satisfy: At the same time, the valve core of the steering valve moves, and the main controller detects whether the displacement direction d and displacement size Δt of the valve core of the steering valve are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed to assist the hydraulic system in steering. At the same time, the main controller detects the current steering angle of the whole machine in real time. ,when or When the main controller stops outputting the four-wheel differential auxiliary steering control signal, the steering continues by relying on the steering hydraulic system and the mass inertia of the whole machine until the steering wheel or the electronic steering handle stops steering or the main controller stops steering when detecting the limit angle signal of the articulation position angle sensor or the frame stops steering when hitting the limit device; wherein, Indicates a set angle value. Indicates the left and right steering limit angles of the vehicle. Indicates another set angle value.

[0011] Furthermore, the four-wheel differential control signal is output according to the set control strategy, and the steering angle is Not Available When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller detects the valve core displacement direction d and displacement size Δt of the steering valve, and determines whether the displacement direction d and displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops outputting the signal. When the signal is not 0, the next action is determined according to the detected steering system pressure p. When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller has no four-wheel differential auxiliary steering control signal output. When A-Δp≤p≤A, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed state, and then continues to detect the current steering angle of the whole machine. Rate of change ,when When it is not 0, the whole machine will turn and continue to turn. When it is equal to 0, the main controller outputs a four-wheel differential auxiliary steering control signal until the whole machine starts to turn; wherein A represents the high-pressure overflow pressure set by the steering system, and Δp represents a set pressure difference.

[0012] Secondly, a four-wheel independent motor driven articulated vehicle steering control device is provided, comprising: a data acquisition module for detecting in real time the current steering angle, vehicle speed, valve core displacement direction and size of the steering valve of the whole machine; an auxiliary steering module for calculating a four-wheel differential auxiliary steering control signal according to the current steering angle, vehicle speed, valve core displacement direction and size of the steering valve of the whole machine, and outputting a four-wheel differential auxiliary steering control signal according to a set control strategy, which is used to assist the steering of the hydraulic system, thereby improving the unstable shaking of the whole machine during steering start and steering stop, reducing the impact during steering stop, reducing steering energy consumption and maintaining synchronization between hydraulic steering and differential auxiliary steering.

[0013] According to a third aspect, a four-wheel independent motor driven articulated vehicle is provided, wherein the vehicle is equipped with the four-wheel independent motor driven articulated vehicle steering control device according to the second aspect.

[0014] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention calculates a four-wheel differential assisted steering control signal according to the current steering angle of the whole machine, the vehicle speed, the direction and size of the valve core displacement of the steering valve, and outputs the four-wheel differential assisted steering control signal according to a set control strategy, which is used to assist the steering of the hydraulic system, improves the unstable shaking of the whole machine during steering start and steering stop, reduces the impact during steering stop, reduces steering energy consumption, and reduces the tire wear problem caused by the lack of synchronization between hydraulic steering and differential assisted steering. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Schematic diagram of the steering system principle of an articulated vehicle driven by four independent motors in an embodiment of the present invention; Figure 2 This is a schematic diagram of the main process of a steering control method for an articulated vehicle driven by four independent motors provided by an embodiment of the present invention; Figure 1 In: 1. Hydraulic oil tank; 2. Steering pump; 3. Steering valve; 31. Valve core displacement sensor; 4. Steering cylinder; 5. Steering wheel; 6. Angle sensor; 7. Steering gear; 8. Electronic steering handle; 9. Electronic steering pilot valve; 10. Pressure sensor. DETAILED DESCRIPTION

[0016] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

[0017] Embodiment 1 The main structure of the four-wheel independent motor driven articulated vehicle in the present invention includes: a front frame, a rear frame, four wheel side drive motors respectively arranged on the front frame and the rear frame, four wheel side drive motor reducers, four wheel assemblies, four drive motor controllers; it also includes a main controller, a front and rear frame articulation position angle sensor; such as Figure 1As shown, it also includes: a steering pump 2 (electrically controlled plunger pump or load-sensitive plunger pump), a pressure sensor 10 arranged at the outlet of the steering pump 2, a steering wheel 5 with a hydraulically controlled steering gear 7 plus an angle sensor 6 or an electrically controlled steering handle 8 (integrated angle sensor), an electrically controlled steering pilot valve 9 (used in conjunction with the electrically controlled steering handle 8), a steering valve 3 (a common steering valve or a steering flow amplifying valve, equipped with a valve core displacement sensor 31), and a steering cylinder 4. The inlet of the steering pump 2 is connected to the hydraulic oil tank 1, the outlet of the steering pump 2 is connected to the P port of the steering valve 3, the T port of the steering valve 3 is connected to the hydraulic oil tank 1, the CR port and the CL port of the steering valve 3 are connected to the steering cylinder 4; the L port of the steering valve 3 is respectively connected to the L port of the steering gear 7 and the L port of the electrically controlled steering pilot valve 9; the R port of the steering valve 3 is respectively connected to the R port of the steering gear 7 and the R port of the electrically controlled steering pilot valve 9; the input end of the steering gear 7 is connected to the angle sensor 6 and the steering wheel 5; the input end of the electrically controlled steering pilot valve 9 is connected to the electrically controlled steering handle 8.

[0018] The main valve stem of the steering valve 3 (ordinary steering valve or flow amplification steering valve) is integrated with a displacement sensor. The main controller detects the valve core displacement sensor signal of the steering valve 3 to determine the valve core displacement information, including the valve core displacement direction and displacement size. The valve core displacement direction can determine the steering direction, and the valve core displacement size can determine the valve core opening size. The larger the displacement, the larger the valve core opening, the greater the flow rate of oil supplied to the steering cylinder 4, the faster the steering speed, and the larger the valve opening, the faster the driver's expected steering speed. According to the valve core displacement sensor signal and the vehicle speed signal, the main controller calculates the required differential speed of the four wheels, and controls the motor controller to output the control voltage corresponding to the required differential speed to the four motors to obtain the differential torque, thereby completing the differential auxiliary steering control. After detecting the displacement signal of the valve core displacement sensor 31 of the steering valve 3 and the vehicle speed signal, the main controller will output the differential control voltage to the four motors within 100ms (main controller response time), and the wheel differential action and the steering cylinder 4 action are almost synchronized (the faster the main controller responds, the more synchronized the differential assisted steering and hydraulic steering), avoiding the energy loss caused by the asynchronous control actions of the two, the unstable shaking of the whole machine steering startup process and the tire wear caused by tire dragging. At the same time, the steering angle is detected. The extreme steering angle to the left or right of an articulated vehicle in the middle position is generally less than or equal to 45°. When it is detected that the steering is approaching the left or right extreme positions, the wheel-side differential assisted steering is stopped, and the steering cylinder continues to move and the vehicle's rotational inertia makes the vehicle turn to the left or right extreme positions, and hits the limit to stop the steering or the main controller stops the steering according to the extreme angle signal of the articulation position angle sensor. At this time, the differential assist stops before the vehicle turns to the extreme angle, which can reduce the impact force caused by the sudden stop of the front and rear frame articulation positions when the steering reaches the limit, thereby improving the durability of the frame articulation positions, reducing the degree of shaking of the vehicle, and also improving driving comfort and energy utilization. When the vehicle starts to turn near the extreme steering angle, the main controller detects the steering hydraulic system pressure. When the pressure is lower than the set pressure value (lower than the maximum system pressure), steering is only performed through the hydraulic system; when the pressure is higher than this value and lower than the maximum overflow pressure set by the system, the main controller only provides a lower differential torque to assist steering, and at the same time detects the vehicle angle change and dynamically increases the differential auxiliary steering torque to make the whole machine turn. This can reduce the impact and damage to the frame articulation caused by the instantaneous stop of the steering to the extreme position, as well as the wear on the tires caused by the untimely differential stop, and also reduce energy loss.

[0019] A steering control method for an articulated vehicle driven by four independent motors, comprising: detecting in real time the current steering angle of the whole machine, the vehicle speed, the direction and size of the valve core displacement of a steering valve; calculating a four-wheel differential auxiliary steering control signal according to the current steering angle, the vehicle speed, the direction and size of the valve core displacement of the steering valve of the whole machine, and outputting the four-wheel differential auxiliary steering control signal according to a set control strategy, which is used to assist the steering of a hydraulic system, thereby improving the unstable shaking of the whole machine during steering start and steering stop, reducing the impact during steering stop, reducing steering energy consumption, and maintaining synchronization between hydraulic steering and differential auxiliary steering.

[0020] like Figure 1 , Figure 2 As shown, when the steering system is a load-sensitive pump steering system, and the steering mode is steering by a steering wheel or an electronically controlled steering handle, or both steering modes coexist, there is no need to connect an angle sensor 6 between the steering wheel 5 and the steering gear 7. When the steering valve 3 is a common steering valve, the steering gear 7 used in conjunction with the steering valve 3 is a steering gear without an LS signal output port. When the steering wheel 5 rotates, the rotating shaft of the steering gear 7 rotates, and the L port or R port of the steering gear 7 outputs a left or right steering pilot oil signal to the steering valve 3, controls the movement of the valve core of the steering valve 3, and drives the valve core displacement sensor 31 to operate and output an electrical signal. After the valve core moves, the steering pump 2 and the steering cylinder 4 are connected. At the same time, the load-sensitive steering pump receives the steering cylinder high-pressure oil signal transmitted by the steering valve 3 to perform variable displacement control, and the steering cylinder 4 starts to operate. The faster the steering wheel 5 rotates, the greater the displacement of the valve core movement, the greater the displacement of the load-sensitive pump, and the faster the steering speed of the vehicle. Similarly, when the steering wheel rotates slower, the steering speed of the vehicle is slower. When the steering valve 3 is a common steering valve and the steering mode is the electronically controlled steering handle steering, the electronically controlled steering handle outputs different electrical signals to the electronically controlled steering pilot valve after it moves to the left or right. The electronically controlled steering pilot valve moves after receiving the electrical signal, and the L or R port of the electronically controlled steering pilot valve corresponds to outputting the pilot oil to the steering valve to control the action of the steering valve 3. The action of the steering valve 3 drives the valve core displacement sensor 31 to move and output an electrical signal. After the action of the steering valve 3, the steering pump 2 is connected to the steering cylinder 4, and the steering cylinder 4 starts to move. At the same time, the load-sensitive steering pump receives the steering cylinder high-pressure oil signal transmitted by the steering valve 3 to perform variable displacement control. The greater the angle of the electronically controlled steering handle, the greater the movement displacement of the steering valve spool, the greater the displacement of the load-sensitive pump, and the faster the steering speed of the vehicle. Similarly, the smaller the rotation angle of the electronic steering handle, the slower the steering speed of the vehicle; steering wheel steering and electronic steering handle steering can coexist, which is achieved by connecting the L and R ports of the steering gear 7 in parallel with the L and R ports of the electric steering pilot valve 9 and then connecting them to the L and R ports of the steering valve 3.

[0021] When the steering valve 3 is a flow amplification steering valve and the steering wheel is used for steering, a steering gear with an LS signal port is required for use. When the steering wheel 5 rotates, the steering gear 7 is driven to rotate. The L or R port of the steering gear 7 outputs a left or right steering pilot oil signal to the L or R port of the flow amplification steering valve. At the same time, the steering gear LS oil signal is transmitted to the flow amplification steering valve and the load-sensitive steering pump to control the valve core movement of the flow amplification steering valve, and drive the valve core displacement sensor 31 to operate and output an electrical signal. After the valve core moves, the steering pump 2 and the steering cylinder 4 are connected, and the steering cylinder 4 starts to operate. The faster the steering wheel 5 rotates, the greater the displacement of the valve core, the greater the displacement of the load-sensitive pump, and the faster the steering speed of the vehicle. Similarly, when the steering wheel rotates slower, the steering speed of the vehicle is slower. When the steering mode is electronically controlled steering handle steering, the electronically controlled steering handle outputs different electrical signals to the electronically controlled steering pilot valve after turning left or right. The electronically controlled steering pilot valve acts after receiving the electrical signal, and the L or R port of the electronically controlled steering pilot valve corresponds to outputting the pilot oil to the L or R port of the flow amplification steering valve. At the same time, the LS oil signal of the electronically controlled steering pilot valve is transmitted to the flow amplification steering valve and the load-sensitive steering pump to control the movement of the valve core of the flow amplification steering valve, and drive the valve core displacement sensor to act and output an electrical signal. After the movement of the valve core, the steering pump and the steering cylinder are connected, and the steering cylinder starts to act. The greater the angle of the electronically controlled steering handle, the greater the movement displacement of the valve core of the flow amplification steering valve, the greater the displacement of the load-sensitive pump, and the faster the steering speed of the vehicle. Similarly, the smaller the rotation angle of the electronic steering handle, the slower the steering speed of the vehicle; steering wheel steering and electronic steering handle steering can also coexist, which is achieved by connecting the L, R and LS ports of the steering gear in parallel with the L, R and LS ports of the electronic steering pilot valve and then connecting them to the L, R and LS ports of the flow increasing valve.

[0022] like Figure 2 As shown above, the load-sensing pump steering system equipped with a common steering valve or a flow-amplifying steering valve, when the steering wheel or the electronically controlled steering handle is moved, the main controller detects the current steering angle of the whole machine. , when the steering angle satisfy: At the same time, the steering gear or the electronically controlled steering pilot valve is actuated, and the main valve core of the steering valve is actuated after receiving the LS and L or R hydraulic oil signals. At the same time, the load-sensitive pump receives the pilot LS oil pressure signal from the steering valve or the steering gear or the electronically controlled steering pilot valve, and proportionally outputs the flow to the steering valve. The main controller detects the displacement direction and size signal of the displacement sensor of the steering valve, and determines whether the displacement direction d and the displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed to assist the hydraulic system in steering. At the same time, the main controller detects the current steering angle of the whole machine in real time. ,when or When the main controller stops outputting the four-wheel differential auxiliary steering control signal, the steering continues by relying on the steering hydraulic system and the mass inertia of the whole machine until the steering wheel or the electronic steering handle stops steering or the main controller stops steering when detecting the limit angle signal of the articulation position angle sensor or the frame stops steering when hitting the limit device; wherein, Indicates a set angle value. , Indicates the left and right steering limit angles of the vehicle. Indicates another set angle value, When the steering angle Not Available When the steering gear or the electric steering pilot valve is in the range, the steering gear or the electric steering pilot valve is activated, and then the main valve core is activated after the steering valve receives the LS hydraulic oil signal. At the same time, the load-sensitive pump receives the pilot LS oil pressure signal transmitted by the steering valve or the steering gear or the steering pilot valve, and outputs the proportional flow to the steering valve. The main controller detects the displacement direction d and displacement size Δt of the valve core of the steering valve, and determines whether the displacement direction d and displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller detects the detected steering system. The next action is determined by the steering system pressure p. When the steering system pressure p is not in the pressure range of (A-Δp, A), the main controller has no four-wheel differential auxiliary steering control signal output. When A-Δp≤p≤A, the main controller calculates the four-wheel differential auxiliary steering control signal according to the current vehicle speed state and outputs the weakened four-wheel differential auxiliary steering control signal (the weakened four-wheel differential auxiliary steering control signal can be 1 / 10, 1 / 5, 1 / 4, 1 / 3, 1 / 2... of the calculated value, or other fixed values, etc.), and then continues to detect the current steering angle of the whole machine. Rate of change ,when When it is not 0, the whole machine will turn and continue to turn. When it is equal to 0, the main controller outputs an enhanced four-wheel differential auxiliary steering control signal (the enhancement methods include: enhancing by geometric progression, such as the enhanced signal can be 1.1 times, 1.2 times, 1.3 times... of the weakened signal; enhancing by arithmetic progression, such as the enhanced signal can be the current weakened signal plus a fixed value; enhancing in other function forms, etc.), until the whole machine steering can turn and continue to turn; wherein A represents the high-pressure overflow pressure set by the steering system, Δp represents a set pressure difference, 0Mpa<Δp≤8Mpa.

[0023] Embodiment 2 The difference between this embodiment and embodiment one is that this embodiment adopts an electronically controlled pump steering system, and the steering method is steering by a steering wheel or an electronically controlled steering handle or a coexistence of the two steering methods. At this time, an angle sensor needs to be connected between the steering wheel and the steering gear, and the steering valve is an ordinary steering valve or a flow amplification valve.

[0024] When the steering valve is a common steering valve, the steering gear used in conjunction with it is a steering gear without an LS signal output port. When the steering wheel is turned, the angle sensor and the steering gear shaft are driven to rotate. The L or R port of the steering gear outputs a left or right steering pilot oil signal to the steering valve, which controls the movement of the valve core of the steering valve, drives the valve core displacement sensor to operate and output an electrical signal. After the valve core moves, the steering pump and the steering cylinder are connected. At the same time, the electronically controlled steering pump receives the electrical signal from the steering wheel angle sensor to control the variable displacement, and the steering cylinder starts to move. The faster the steering wheel speed, the greater the displacement of the valve core, the greater the displacement of the electronically controlled pump, and the faster the steering speed of the vehicle. Similarly, the slower the steering wheel speed, the slower the steering speed of the whole vehicle; when the steering valve is an ordinary steering valve and the steering method is electronic steering handle steering, the electronic steering handle outputs different electrical signals to the electronic steering pilot valve after moving left or right, and the electronic steering pilot valve moves according to the received electrical signal, and the L or R port of the electronic steering pilot valve corresponds to output pilot oil to the steering valve to control the movement of the steering valve. The steering valve moves and drives the valve core displacement sensor to move and output electrical signals. After the steering valve moves, the steering pump is connected to the steering cylinder. At the same time, the electronic steering pump receives the rotation angle electrical signal of the electronic steering handle for variable displacement control, and the steering cylinder starts to move. The greater the angle of the electronic steering handle, the greater the movement displacement of the valve core of the steering valve, the greater the displacement of the electronic pump, and the faster the steering speed of the whole vehicle. Similarly, the smaller the rotation angle of the electronic steering handle, the slower the steering speed of the vehicle; steering wheel steering and electronic steering handle steering can also coexist, which is achieved by connecting the L and R ports of the steering gear in parallel with the L and R ports of the electric steering pilot valve and then connecting them to the L and R ports of the steering valve.

[0025] When the steering valve is a flow amplification steering valve and steering is adopted, a steering gear with an LS signal port is required for use. When the steering wheel is turned, the angle sensor and the steering gear are driven to rotate. The L or R port of the steering gear outputs a left or right steering pilot oil signal to the L or R port of the flow amplification steering valve. The LS oil signal of the steering gear is transmitted to the flow amplification steering valve. At the same time, the electrical signal of the angle sensor is output to the electronically controlled pump to control the movement of the valve core of the flow amplification steering valve, and drive the valve core displacement sensor to move and output an electrical signal. After the movement of the valve core, the steering pump and the steering cylinder are connected. At the same time, the electronically controlled steering pump receives the electrical signal of the steering wheel angle sensor for variable displacement control, and the steering cylinder starts to move. The faster the steering wheel speed, the greater the displacement of the valve core, the greater the displacement of the electronically controlled steering pump, and the faster the steering speed of the whole vehicle. Similarly, the slower the steering wheel speed, the slower the steering speed of the whole vehicle; when the steering mode is electronically controlled steering handle steering, the electronically controlled steering handle outputs different electrical signals to the electronically controlled steering pilot valve after turning left or right, and the electronically controlled steering pilot valve acts after receiving the electrical signal, and the L or R port of the electronically controlled steering pilot valve corresponds to the output of pilot oil to the L or R port of the flow amplification steering valve, and at the same time, the LS oil signal of the electronically controlled steering handle is transmitted to the flow amplification steering valve to control the valve core movement of the flow amplification steering valve, and drive the valve core displacement sensor to act and output an electrical signal, and after the valve core moves, the steering pump and the steering cylinder are connected, and at the same time, the electronically controlled steering pump receives the electrical signal of the angle sensor of the electronically controlled steering handle for variable displacement control, and the steering cylinder starts to act, and the greater the angle of the electronically controlled steering handle, the greater the movement displacement of the valve core of the flow amplification steering valve, the greater the displacement of the electronically controlled steering pump, and the faster the steering speed of the whole vehicle. Similarly, the smaller the rotation angle of the electronic steering handle, the slower the steering speed of the vehicle; steering wheel steering and electronic steering handle steering can also coexist, which is achieved by connecting the L, R and LS ports of the steering gear in parallel with the L, R and LS ports of the electronic steering pilot valve and then connecting them to the L, R and LS ports of the flow amplification steering valve.

[0026] like Figure 2 As shown, the above electronically controlled pump steering system equipped with a common steering valve or a flow amplification steering valve, when the steering wheel or the electronically controlled steering handle moves, the main controller first detects the angle sensor signal of the steering wheel or the electronically controlled steering handle. When the electrical signal of the angle sensor of the steering wheel or the electronically controlled steering handle is 0, the output flow of the electronically controlled pump is 0 or keeps the standby flow, and the whole machine has no steering action or the steering stops. When the electrical signal of the angle sensor of the steering wheel or the electronically controlled steering handle is not 0, the main controller detects the current steering angle of the whole machine. , when the steering angle satisfy: After the steering gear or the electronically controlled steering pilot valve is actuated, the steering valve receives the LS and L or R hydraulic oil signals and the main valve core is actuated. At the same time, the electronically controlled steering pump receives the electrical signal from the angle sensor of the steering wheel or the electronically controlled steering handle and outputs a proportional flow rate to the steering valve. The main controller detects the displacement direction and size of the valve core of the steering valve, and determines whether the displacement direction d and the displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed state to assist the hydraulic system in steering. At the same time, the main controller detects the current steering angle of the whole machine in real time. ,when or When the main controller stops the output of the four-wheel differential auxiliary steering control signal, the hydraulic system and the mass inertia of the whole machine continue to steer until the steering wheel or handle stops steering or the controller stops steering according to the limit angle signal of the articulated position angle sensor or the frame hits the limit device and stops steering. When the steering wheel or the electronically controlled steering handle moves, the steering angle of the whole machine is detected. Not Available When the steering gear or the electronically controlled steering pilot valve is activated, the steering valve receives the LS and L or R hydraulic oil signals and then the main valve core is activated. At the same time, the electronically controlled steering pump receives the electrical signal of the angle sensor of the steering wheel or the electronically controlled steering handle and then outputs the proportional flow to the steering valve. The main controller detects the displacement direction d and displacement size Δt signal of the steering valve core. The main controller detects the displacement direction d and displacement size Δt of the steering valve core and determines whether the displacement direction d and displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the next action is determined according to the detected steering system pressure p. When the steering system pressure p is not in the pressure range of (A-Δp, A), the main controller has no four-wheel differential auxiliary steering control signal output. When A-Δp≤p≤A, the main controller calculates the four-wheel differential auxiliary steering control signal according to the current vehicle speed state and outputs the weakened four-wheel differential auxiliary steering control signal. After that, the current steering angle of the whole machine is continuously detected. Rate of change ,when When it is not 0, the whole machine will turn and continue to turn. When it is equal to 0, the main controller enhances the output of the four-wheel differential auxiliary steering control signal until the whole machine can turn and continue to turn.

[0027] Embodiment 3 Based on the steering control method for a four-wheel independent motor driven articulated vehicle described in Embodiment 1 and Embodiment 2, this embodiment provides a steering control device for a four-wheel independent motor driven articulated vehicle, comprising: The data acquisition module is used to detect the current steering angle of the whole machine, vehicle speed, and the displacement direction and size of the valve core of the steering valve in real time; The auxiliary steering module is used to calculate the four-wheel differential auxiliary steering control signal according to the current steering angle of the whole machine, the vehicle speed, the valve core displacement direction and size of the steering valve, and output the four-wheel differential auxiliary steering control signal according to the set control strategy to assist the hydraulic system steering, thereby improving the unstable shaking of the whole machine when starting and stopping the steering, reducing the impact when stopping the steering, reducing the steering energy consumption and maintaining the synchronization of hydraulic steering and differential auxiliary steering.

[0028] Embodiment 4 Based on the four-wheel independent motor driven articulated vehicle steering control device described in Example 3, this embodiment provides a four-wheel independent motor driven articulated vehicle, and the vehicle is equipped with the four-wheel independent motor driven articulated vehicle steering control device described in Example 3.

[0029] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A steering control method for a four-wheel independent motor driven articulated vehicle, characterized in that: include: Real-time detection of the current steering angle, vehicle speed, and displacement direction and size of the steering valve core of the whole machine; According to the current steering angle of the whole machine, vehicle speed, valve core displacement direction and size of the steering valve, the four-wheel differential auxiliary steering control signal is calculated, and the four-wheel differential auxiliary steering control signal is output according to the set control strategy to assist the hydraulic system steering, thereby improving the unstable shaking of the whole machine when steering starts and stops, reducing the impact when steering stops, reducing steering energy consumption and maintaining the synchronization of hydraulic steering and differential auxiliary steering.

2. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 1, characterized in that: The vehicle adopts a load-sensitive pump steering system, the steering method is steering with a steering wheel and / or an electronically controlled steering handle, and the steering valve is a common steering valve or a flow amplification valve.

3. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 2, characterized in that: Output four-wheel differential control signals according to the set control strategy, including: When the steering wheel or the electronic steering handle moves, the main controller detects the current steering angle of the whole machine. , when the steering angle satisfy: At the same time, the valve core of the steering valve moves, and the main controller detects whether the displacement direction d and displacement size Δt of the valve core of the steering valve are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed to assist the hydraulic system in steering. At the same time, the main controller detects the current steering angle of the whole machine in real time. ,when or When the main controller stops outputting the four-wheel differential auxiliary steering control signal, the steering continues by relying on the steering hydraulic system and the mass inertia of the whole machine until the steering wheel or the electronic steering handle stops steering or the main controller stops steering when detecting the limit angle signal of the articulation position angle sensor or the frame stops steering when hitting the limit device; in, Indicates a set angle value. Indicates the left and right steering limit angles of the vehicle. Indicates another set angle value.

4. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 3, characterized in that: Outputting four-wheel differential control signals according to the set control strategy also includes: When the steering angle Not Available When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller detects the valve core displacement direction d and displacement size Δt of the steering valve, and determines whether the displacement direction d and displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops outputting the signal. When the signal is not 0, the next action is determined according to the detected steering system pressure p. When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller has no four-wheel differential auxiliary steering control signal output. When A-Δp≤p≤A, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed state, and then continues to detect the current steering angle of the whole machine. Rate of change ,when When it is not 0, the whole machine will turn and continue to turn. When it is equal to 0, the main controller outputs a four-wheel differential auxiliary steering control signal until the whole machine starts to turn; Wherein, A represents the high-pressure relief pressure set by the steering system, and Δp represents a set pressure difference.

5. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 1, characterized in that: The vehicle adopts an electronically controlled pump steering system, the steering method is steering with a steering wheel and / or an electronically controlled steering handle, and the steering valve is a common steering valve or a flow amplification valve.

6. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 5, characterized in that: Output four-wheel differential control signals according to the set control strategy, including: The main controller detects the angle sensor signal of the steering wheel or the electronic steering handle. When the electrical signal of the angle sensor of the steering wheel or the electronic steering handle is 0, the output flow of the electronically controlled pump is 0 or maintains the standby flow, and the whole machine has no steering action or the steering stops.

7. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 6, characterized in that: Outputting four-wheel differential control signals according to the set control strategy also includes: When the electrical signal of the angle sensor of the steering wheel or the electronic steering handle is not 0, the main controller detects the current steering angle of the whole machine. , when the steering angle satisfy: At the same time, the valve core of the steering valve moves, and the main controller detects whether the displacement direction d and displacement size Δt of the valve core of the steering valve are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops the signal output. When the signal is not 0, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed to assist the hydraulic system in steering. At the same time, the main controller detects the current steering angle of the whole machine in real time. ,when or When the main controller stops outputting the four-wheel differential auxiliary steering control signal, the steering continues by relying on the steering hydraulic system and the mass inertia of the whole machine until the steering wheel or the electronic steering handle stops steering or the main controller stops steering when detecting the limit angle signal of the articulation position angle sensor or the frame stops steering when hitting the limit device; in, Indicates a set angle value. Indicates the left and right steering limit angles of the vehicle. Indicates another set angle value.

8. The steering control method for a four-wheel independent motor driven articulated vehicle according to claim 7, characterized in that: Outputting four-wheel differential control signals according to the set control strategy also includes: When the steering angle Not Available When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller detects the valve core displacement direction d and displacement size Δt of the steering valve, and determines whether the displacement direction d and displacement size Δt are 0. When the signal is 0, the main controller has no four-wheel differential auxiliary steering control signal output or stops outputting the signal. When the signal is not 0, the next action is determined according to the detected steering system pressure p. When the steering system pressure p is not within the (A-Δp, A) pressure range, the main controller has no four-wheel differential auxiliary steering control signal output. When A-Δp≤p≤A, the main controller calculates and outputs the four-wheel differential auxiliary steering control signal according to the current vehicle speed state, and then continues to detect the current steering angle of the whole machine. Rate of change ,when When it is not 0, the whole machine will turn and continue to turn. When it is equal to 0, the main controller outputs a four-wheel differential auxiliary steering control signal until the whole machine starts to turn; Wherein, A represents the high-pressure relief pressure set by the steering system, and Δp represents a set pressure difference.

9. A steering control device for an articulated vehicle driven by four independent motors, characterized in that: include: The data acquisition module is used to detect the current steering angle of the whole machine, vehicle speed, and the displacement direction and size of the valve core of the steering valve in real time; The auxiliary steering module is used to calculate the four-wheel differential auxiliary steering control signal according to the current steering angle of the whole machine, the vehicle speed, the valve core displacement direction and size of the steering valve, and output the four-wheel differential auxiliary steering control signal according to the set control strategy to assist the hydraulic system steering, thereby improving the unstable shaking of the whole machine when starting and stopping the steering, reducing the impact when stopping the steering, reducing the steering energy consumption and maintaining the synchronization of hydraulic steering and differential auxiliary steering.

10. A four-wheel independent motor driven articulated vehicle, characterized in that: The vehicle is equipped with the four-wheel independent motor driven articulated vehicle steering control device according to claim 9.

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