Steering control system and vehicle

Abstract

The application relates to the technical field of vehicle steering control, and discloses a steering control system and a vehicle, the system comprising a main steering module, an auxiliary steering module and a control module, the control module being connected with an electric power steering device of the main steering module and an electric power-assisted cylinder of the auxiliary steering module, wherein the electric power steering device is used for providing first steering assistance for the main steering module; the electric power-assisted cylinder is used for providing second steering assistance for the auxiliary steering module; the control module is connected with the electric power steering device and the electric power-assisted cylinder, and is used for adjusting the first steering assistance according to the steering condition of the main steering module and / or adjusting the second steering assistance according to the steering condition of the auxiliary steering module. Through electric power control steering, the application can flexibly adjust the steering assistance, solves the problem that a gap cannot be handled in the transmission process, improves transmission accuracy and transmission efficiency, and makes the steering operation of the driver be instantly and accurately transmitted to the wheels, so that the accuracy and sensitivity of the control are significantly improved.

Description

Technical Field

[0001] This invention relates to the field of vehicle steering control technology, specifically to a steering control system and a vehicle. Background Technology

[0002] Currently, in engineering vehicles, such as wheeled cranes, the steering system generally uses a hydraulic power steering system. This system typically consists of a mechanical steering system with the addition of a hydraulic power steering unit. The engine drives a power steering pump, converting mechanical energy into hydraulic energy, which then drives the hydraulic power steering cylinder to rotate the wheels. However, the mechanical structure results in the control mechanism containing multiple kinematic pairs, creating clearances during transmission that are difficult to adjust. This leads to inaccurate transmission and an inability to accurately respond to the driver's steering needs. Summary of the Invention

[0003] In view of this, the present invention provides a steering control system and a vehicle to solve the problem of inaccurate steering control.

[0004] In a first aspect, the present invention provides a steering control system, comprising: a main steering module, an auxiliary steering module, and a control module, wherein the control module is connected to an electric steering gear of the main steering module and to an electric power assist cylinder of the auxiliary steering module, wherein the electric steering gear is used to provide a first steering assist to the main steering module; the electric power assist cylinder is used to provide a second steering assist to the auxiliary steering module; and the control module is connected to the electric steering gear and the electric power assist cylinder, and is used to adjust the first steering assist according to the steering condition of the main steering module, and / or adjust the second steering assist according to the steering condition of the auxiliary steering module.

[0005] The steering control system provided by this invention provides steering assistance to the corresponding main steering module and auxiliary steering module through an electric steering gear and an electric power steering cylinder, and is connected to a control module. The control module adjusts the corresponding steering assistance according to the operating status of the main steering module and auxiliary steering module. This invention, through electric steering control, can flexibly adjust the steering assistance according to the steering conditions, solving the problem of unmanageable backlash during transmission, improving transmission accuracy and efficiency, and enabling the driver's steering operations to be transmitted to the wheels instantly and accurately, significantly improving the precision and sensitivity of handling.

[0006] In one optional embodiment, the main steering module further includes: a steering wheel, a steering column, an angle actuator, a steering drive shaft, a steering drop arm, a first steering tie rod, a first steering drive axle, a first angle sensor, a second angle sensor, a third angle sensor, and a torque sensor; the steering wheel, steering column, angle actuator, steering drive shaft, steering drop arm, electric steering gear, first steering tie rod, and first steering drive axle are sequentially connected and arranged to drive the first wheel corresponding to the first steering drive axle to steer according to the steering force acting on the steering wheel and the first steering assist; the first angle sensor is arranged at the input end of the steering column to monitor the first rotation angle and rotational angular velocity of the steering wheel; the second angle sensor is deployed at the electric steering gear to monitor the second rotation angle of the electric steering gear input shaft; the torque sensor is deployed at the electric steering gear to monitor the current torque of the electric steering gear input shaft; and the third angle sensor is deployed at the first steering drive axle to monitor the third rotation angle of the first wheel.

[0007] This invention, by installing a transmission device, angle sensor, and torque sensor corresponding to the electric steering gear on the main steering module, enables control of the main steering module based on the rotation of the steering wheel and the assistance of the electric steering gear, thereby improving the sensitivity of steering control based on the steering wheel.

[0008] In one optional implementation, the control module is connected to a first angle sensor, a second angle sensor, and a torque sensor, and adjusts the first steering assist according to the steering status of the main steering module. This includes: acquiring a first rotation angle, a rotation angular velocity, a second rotation angle, a current torque, and a current vehicle speed; and acquiring a predetermined standard steering assist curve and a compensated steering assist curve; calculating a first angle difference between the first rotation angle and the second rotation angle; if the first angle difference is less than or equal to a first preset angle threshold, then determining the first steering assist based on the current torque, the current vehicle speed, and the standard steering assist curve; if the first angle difference is greater than the first preset angle threshold, then determining the first steering assist based on the first rotation angular velocity, the current torque, the current vehicle speed, and the compensated steering assist curve.

[0009] This invention determines the steering assist curve based on the rotation angle of the steering wheel and the rotation angle of the electric steering unit. When there is a gap that makes it impossible for the user to control the steering wheel, timely assistance compensation can be provided, so that the driver's steering operation can be transmitted to the wheels instantly and accurately, significantly improving the precision and sensitivity of the control.

[0010] In one optional embodiment, the auxiliary steering module further includes: a steering rocker arm, a second steering tie rod, a second steering drive axle, and a fourth angle sensor; the electric power steering cylinder, the steering rocker arm, the second steering tie rod, and the second steering drive axle are sequentially connected and arranged to drive the second wheel corresponding to the second steering drive axle to steer according to the steering force and the second steering assist applied to the steering wheel; the fourth angle sensor is deployed on the second steering drive axle to monitor the fourth rotation angle of the second wheel.

[0011] This invention, by installing a transmission device and angle sensor corresponding to the electric power steering cylinder in the auxiliary steering module, enables the rear axle to rotate under the control of the electric power steering cylinder, based on the rotation of the front axle. There is no need for a mechanical connection between the front and rear axles, reducing the probability of gaps, and the response is faster and the transmission efficiency is higher.

[0012] In one optional implementation, the control module is connected to the third angle sensor and the fourth angle sensor, and adjusts the second steering assist according to the steering status of the auxiliary steering module, including: acquiring the third rotation angle and the fourth rotation angle; determining the theoretical rotation angle of the second wheel based on the third rotation angle according to a predetermined wheel rotation angle relationship function; calculating the second angle difference between the third rotation angle and the theoretical rotation angle; if the second angle difference is less than or equal to a second preset angle threshold, then determining the second steering assist to be a preset value.

[0013] If the second angle difference is greater than the second preset angle threshold, then adjust the second steering assist until the second angle difference is less than or equal to the second preset angle threshold.

[0014] This invention determines the theoretical rotation angle of the rear axle by measuring the rotation angle of the front axle, thus determining whether the rear axle needs to provide steering assistance and accurately implementing various modes including all-wheel steering, crab steering, rear axle locking, and independent rear axle steering.

[0015] In one optional implementation, the electric power steering cylinder is further equipped with a stroke sensor; the stroke sensor is used to monitor the cylinder position of the electric power steering cylinder and send the cylinder position to the control module; the control module performs mid-position calibration and limit position calibration of the electric power steering cylinder according to the cylinder position and the fourth rotation angle, and adjusts the second steering assist based on the limit position calibration.

[0016] This invention calibrates the electric power-assisted cylinder, ensuring its accuracy and further eliminating positional deviations caused by mechanical clearances and installation errors.

[0017] In one alternative implementation, adjusting the second steering assist based on the limit position calibration includes: if the position of the electric power assist cylinder exceeds the maximum or minimum position after the limit position calibration after responding to the second steering assist, then reducing the second steering assist.

[0018] This invention limits the power steering based on the extreme position calibration, which can reduce the power steering output and increase the feel, thereby serving as a warning to the user and ensuring driving safety.

[0019] In one alternative implementation, one end of the electric power-assisted cylinder is connected to the frame, and the other end is connected to the steering rocker arm, and is located on the side of the frame.

[0020] This invention places the electric power-assisted cylinder on the side of the vehicle frame, which, compared to placing it on the steering axle, allows for flexible design of the assist torque by adjusting the length of the robotic arm, and reduces the risk of damage caused by road conditions.

[0021] In one alternative implementation, the system further includes a power supply module and a generator; the power supply module is connected to the generator, and the generator is connected to the electric steering gear and the electric power assist cylinder, for providing power to the electric steering gear and the electric power assist cylinder.

[0022] This invention, by deploying a generator and power supply module, can provide power to the electric steering gear and electric power assist cylinder, ensuring that the steering system is completed based on electric control, and improving the flexibility and accuracy of steering assist adjustment.

[0023] In a second aspect, the present invention provides a vehicle comprising: a frame and a steering control system according to the first aspect or any corresponding embodiment thereof, wherein the frame includes a first wheel and a second wheel.

[0024] Since the vehicle includes the steering control system of the first aspect described above or any of its corresponding embodiments, and has the same effect as the steering control system, it will not be described again here. Attached Figure Description

[0025] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0026] Figure 1 This is a structural block diagram of the steering control system according to an embodiment of the present invention;

[0027] Figure 2 This is a specific structural block diagram of the steering control system according to an embodiment of the present invention;

[0028] Figure 3 This is a structural block diagram of the main steering module of the steering control system according to an embodiment of the present invention;

[0029] Figure 4 This is a structural block diagram of the auxiliary steering module of the steering control system according to an embodiment of the present invention. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0031] This invention applies to scenarios involving vehicle steering control. Vehicle steering control is achieved by transmitting motion and force through mechanical connections in a mechanical transmission system. Small, non-working spaces or looseness, known as mechanical clearances, arise between adjacent components due to design, manufacturing, assembly, or wear factors. Therefore, during steering control, when the driver turns the steering wheel, these component clearances must be eliminated to steer the wheels and prevent excessive steering wheel free play (play). The essence of clearance is to prevent components from jamming (such as gears meshing too tightly, preventing rotation). Therefore, small amounts of play are reserved at the connection points during design (such as the gap between the ball joint and the joint, or the tooth flank clearance of gear meshing). Normal clearance refers to clearances calculated at the factory to ensure flexible rotation without affecting handling (similar to the gap between a door hinge and a door frame). Abnormal clearance refers to clearances that increase after long-term use due to component wear (such as damaged ball joint dust covers or worn gear surfaces), similar to a "loose screw." When the driver turns the steering wheel, force is transmitted to the wheels layer by layer through the steering system. However, due to the gaps between components, this transmission process is divided into two stages: ① Eliminating gaps (ineffective travel): In the initial stage of steering wheel rotation, the force is first used to "fill" the gaps between components (e.g., pushing gears to mesh tightly, straightening the looseness of ball joints). At this time, the wheels will not turn, and the driver will feel "steering wheel spinning freely," just like turning a loose screw, which requires "free-spinning" several times before it can be tightened. ② Steering the wheels (effective travel): After the gaps are "eliminated" (components are in close contact), the rotation of the steering wheel will be transmitted to the wheels through the mechanical structure, causing the wheels to actually turn. At this time, the driver's action will produce a steering effect, but due to the ineffective travel in the early stage, the overall steering response will be delayed. Steering wheel free travel (play) refers to "the angle that the steering wheel travels from the middle position to when the wheels just begin to turn." For example, the free travel of a normal vehicle may be 10°-15° (that is, when the steering wheel is turned 10°-15° to the left or right, the wheels do not move), while the free travel of a vehicle with excessive gaps may reach more than 30°. Therefore, the larger the gap between components, the larger the rotation angle required to "eliminate the gap," resulting in a significant increase in free play (play). When the driver gently turns the steering wheel, the vehicle does not respond, requiring a larger turn to steer. This prevents the driver's steering input from being transmitted to the wheels instantly and accurately, reducing the precision and sensitivity of the steering. Therefore, this invention provides a steering control system that uses an electric steering gear and an electric power steering pump to electrically control the steering system, eliminating mechanical backlash and improving steering precision.

[0032] According to embodiments of the present invention, a steering control system embodiment is provided. It should be noted that, as used below, the term "module" can refer to a combination of software and / or hardware that implements a predetermined function. Although the apparatus described in the following embodiments is preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0033] This embodiment provides a steering control system that can be used in the aforementioned vehicles, such as engineering vehicles like cranes. Figure 1 This is a structural block diagram of the steering control system according to an embodiment of the present invention, such as... Figure 1 As shown, the system includes: a main steering module, an auxiliary steering module, and a control module. The control module is connected to the electric steering gear of the main steering module and to the electric power steering cylinder of the auxiliary steering module. The electric steering gear is used to provide first steering assistance to the main steering module; the electric power steering cylinder is used to provide second steering assistance to the auxiliary steering module; and the control module is connected to the electric steering gear and the electric power steering cylinder to adjust the first steering assistance according to the steering status of the main steering module and / or adjust the second steering assistance according to the steering status of the auxiliary steering module.

[0034] Specifically, in embodiments of the present invention, such as Figure 2 As shown, the main steering module primarily controls the steering of the vehicle's front wheels (the first wheels, usually two). Figure 3 As shown, the main steering module also includes: a steering wheel, a steering column, an angle actuator, a steering drive shaft, a steering drop arm, a first steering tie rod, a first steering drive axle, a first angle sensor, a second angle sensor, a third angle sensor, and a torque sensor. The steering wheel, steering column, angle actuator, steering drive shaft, steering drop arm, electric steering gear, first steering tie rod, and first steering drive axle are sequentially connected. One end of the electric power steering cylinder is connected to the vehicle frame, and the other end is connected to the steering rocker arm, located on the side of the vehicle frame. It is used to steer the first wheel corresponding to the first steering drive axle based on the steering force applied to the steering wheel and the first steering assist. The first angle sensor is located at the input end of the steering column to monitor the first rotation angle and angular velocity of the steering wheel. The second angle sensor is located on the electric steering gear to monitor the second rotation angle of the electric steering gear input shaft. The torque sensor is located on the electric steering gear to monitor the current torque of the electric steering gear input shaft. The third angle sensor is located on the first steering drive axle to monitor the third rotation angle of the first wheel.

[0035] In some optional implementations, the steering wheel, steering column, angle actuator, and steering drive shaft in the main steering module serve as the control mechanism for the driver to operate the steering gear. The steering drop arm and the first steering tie rod (front axle steering tie rod) constitute the main steering linkage mechanism. The front axle steering tie rod is hinged to the front axle (first steering drive axle) and can drive the front axle to steer. The electric steering gear integrates a controller for calculation and control. The input end is connected to the control mechanism, and the output end is connected to the steering axle via the tie rod. When steering is required, the driver rotates the steering wheel to generate an initial steering torque. The torque is transmitted through the steering column to the steering drive shaft and then to the electric steering gear. The second angle sensor and torque sensor within the electric steering gear detect the second rotation angle and current torque of the electric steering gear input shaft (corresponding to the steering wheel) and transmit them to the control module (Electric Power Steering Electronic Control Unit, EPSECU). Based on signals such as the current vehicle speed and the second steering angle, the EPS ECU calculates the required amount of first steering assistance, controls the motor to drive the electric steering gear / rack to move, and converts this movement into lateral swing through the steering drop arm, pushing the first steering tie rod (i.e., the front axle steering tie rod). The first steering tie rod pulls the steering knuckle arm on the first steering drive axle (i.e., the front axle), causing the wheel to deflect around the kingpin. The angle transmission can participate in secondary adjustments of angle or torque during this stage (as in all-wheel steering models).

[0036] In some alternative implementations, the auxiliary steering module primarily controls the steering of the vehicle's rear wheels (the second wheel, typically both). Controlling the rear wheels with this module offers several advantages. At low speeds, such as when parking or turning in tight spaces, the auxiliary steering module allows the rear wheels to turn in the opposite direction to the front wheels, effectively reducing the vehicle's turning radius and improving its maneuverability. At high speeds, such as during high-speed lane changes or when encountering interference while driving straight, the auxiliary steering module allows the rear wheels to turn in the same direction as the front wheels, helping to improve vehicle stability and traction, reduce the impact of crosswinds, and enhance driving safety and comfort. Figure 4 As shown, the auxiliary steering module also includes: a steering rocker arm, a second steering tie rod, a second steering drive axle, and a fourth angle sensor; wherein, the electric power steering cylinder, steering rocker arm, second steering tie rod, and second steering drive axle are sequentially connected and arranged to drive the second wheel corresponding to the second steering drive axle to steer according to the steering force and second steering assistance applied to the steering wheel; the fourth angle sensor is deployed on the second steering drive axle to monitor the fourth rotation angle of the second wheel. Figure 4As shown, one end of the electric power steering cylinder is connected to the vehicle frame, and the other end is connected to the steering rocker arm, located on the side of the frame. Compared to placing it on the steering axle, this allows for flexible design of the assist torque by adjusting the length of the robotic arm, and reduces the risk of damage caused by road conditions. This embodiment of the invention drives and controls the rotation of the auxiliary steering axle wheels through the electric power steering cylinder, resulting in faster response and higher transmission efficiency compared to an electro-hydraulic auxiliary steering system. Furthermore, the electric power steering cylinder functions as both a centering cylinder and a steering assist cylinder, simplifying its structure.

[0037] In some optional embodiments, the steering rocker arm and the second steering tie rod (auxiliary steering bridge tie rod) are auxiliary steering linkage mechanisms. The auxiliary steering bridge tie rod is used to hinge with the rear axle (second steering drive axle) and can drive the rear axle to steer. In this embodiment of the invention, the front and rear axle steering linkages are not connected by a mechanical structure, but are connected to the electric steering gear of the main steering module and the electric power steering pump of the auxiliary steering module through a control module. After the front wheels are steered by the electric steering gear, the electric power steering cylinder, as the power output source of the auxiliary steering module, receives the command from the control module and outputs the corresponding thrust or pull force according to the magnitude of the steering force acting on the steering wheel and the preset second steering assist strategy. This force is transmitted to the steering rocker arm, which, with a fixed fulcrum as the center, converts the linear motion of the electric power steering cylinder into a swinging motion, just like the lever principle, converting the direction and form of the force to provide a suitable power output method for subsequent steering operations. The swinging steering rocker arm further transmits the force to the second steering drive axle (rear axle / auxiliary steering axle) through the second steering tie rod (rear axle / auxiliary steering bridge). The second steering tie rod acts as a connecting bridge, converting the swing of the steering rocker arm into a lateral force that propels the second steering drive axle. The second steering drive axle integrates steering and driving functions; under the action of the lateral force, it causes the corresponding second wheel to deflect, thus achieving the vehicle's steering action.

[0038] In some optional real-time modes, embodiments of the present invention eliminate excess backlash by setting an electric steering gear and an electric power assist pump in the main steering module and the auxiliary steering module respectively, thereby achieving electric control of the steering control system. This avoids the mechanical connection between the main steering module and the auxiliary steering module, reducing the impact of mechanical backlash to a certain extent. However, the mechanical backlash within the main steering module and the auxiliary steering module will gradually increase with the increase of usage time. Therefore, embodiments of the present invention adjust the first steering assist according to the steering condition of the main steering module and adjust the second steering assist according to the steering condition of the auxiliary steering module, thereby flexibly adjusting the steering assist. This allows the free play caused by the control mechanism to be compensated by the program at the steering gear input end, making up for the steering error caused by mechanical backlash and making the control more precise.

[0039] In some alternative implementations, for the main steering module, the control module is connected to the first angle sensor, the second angle sensor, and the torque sensor (e.g., Figure 2 (As shown by the dashed line in the middle), the corresponding first rotation angle, rotational angular velocity, second rotation angle, current torque, and current vehicle speed are obtained. A pre-determined standard steering assist curve and a compensated steering assist curve are also obtained. The assist curve uses the input torque, steering angular velocity, and vehicle speed parameters provided by the ECU as reference variables to determine the steering assist provided. Different steering assist is adapted for low-speed, high-speed, and emergency situations. The adaptation process is determined based on the first rotation angle of the steering wheel and the second rotation angle of the electric steering gear. First, the first angle difference between the first and second rotation angles is calculated. If the first angle difference is less than or equal to a first preset angle threshold, the standard steering assist curve is used, and the first steering assist is determined based on the current torque, current vehicle speed, and the standard steering assist curve. If the first angle difference is greater than the first preset angle threshold, it indicates that the large mechanical clearance results in a significant difference between the steering wheel rotation angle and the electric steering gear rotation angle, making it impossible for the driver's steering operation to be accurately transmitted to the wheels. Therefore, the compensated steering assist curve is used, and the first steering assist is determined based on the first rotational angular velocity, current torque, current vehicle speed, and the compensated steering assist curve. The first preset angle threshold can be determined based on the actual steering effect of the vehicle, and is not limited here. By adjusting the first preset angle threshold, the steering response speed can be improved and the impact of the clearance of the control mechanism can be reduced.

[0040] In some alternative implementations, for the auxiliary steering module, the control module is connected to the third angle sensor and the fourth angle sensor (e.g., Figure 2 (As shown by the dashed line in the middle), thereby obtaining the third rotation angle of the front wheels and the fourth rotation angle of the rear wheels. In this embodiment of the invention, the wheel rotation angles corresponding to the front and rear axles are pre-set to satisfy the Ackermann relation function. That is, according to the Ackermann relation function, the theoretical rotation angle of the rear wheels can be calculated based on the third rotation angle of the front wheels. Ideally, the actual fourth rotation angle of the rear wheels should be consistent with the calculated theoretical rotation angle, or within the allowable error range. Therefore, the second angle difference between the third rotation angle and the theoretical rotation angle is calculated. If the second angle difference is less than or equal to a second preset angle threshold, it proves that it is within the allowable error range. At this time, no additional steering assistance is needed, and the second steering assistance is determined to be a preset value (e.g., zero). If the second angle difference is greater than the second preset angle threshold, it proves that the steering error of the rear wheels is large. Therefore, the second steering assistance is adjusted until the second angle difference is less than or equal to the second preset angle threshold. At this time, through the adjustment of steering assistance by the main steering module and the auxiliary steering module, it is possible to ensure that both the front and rear wheels achieve relatively precise steering control, eliminating steering errors caused by mechanical backlash to the greatest extent.

[0041] In some alternative implementations, in certain wheeled machinery, due to the long transmission path of its control mechanism, the safety of the steering system faces severe challenges if critical mechanical transmission components such as the angle steering gear are disconnected due to an accident. However, this invention utilizes an electric steering gear and an electric power steering cylinder for steering control. Under precise program control, the steering gear can still maintain dynamic following capability to changes in the steering wheel angle. Even if the mechanical connection fails, the system can still continuously output steering commands through electronic compensation algorithms, ensuring the vehicle has basic steering control functions. This enables the vehicle to move short distances in emergencies, greatly improving the vehicle's controllability under extreme conditions and buying valuable time for subsequent rescue and response efforts.

[0042] In some optional implementations, the electric power steering cylinder is also equipped with a stroke sensor. A stroke sensor is a sensor used to detect the displacement (stroke) or position change of a mechanical component. In this embodiment of the invention, it is used to monitor the cylinder position of the electric power steering cylinder and send the cylinder position to the control module. The control module then performs mid-position calibration and limit position calibration of the electric power steering cylinder based on the cylinder position and the fourth rotation angle, and adjusts the second steering assist based on the limit position calibration.

[0043] In some optional implementations, center-position calibration aims to determine the "zero position" of the electric power steering cylinder, i.e., the standard position of the electric power steering cylinder when the vehicle is traveling straight. The specific steps are as follows: ① Initial condition setting: The vehicle is stationary, and the steering wheel is in the center position (straight-line driving state). At this time, the second wheel should remain pointing forward. ② Data acquisition and analysis: The control module reads the data from the current cylinder position sensor and the fourth angle sensor. If the data of both are not at the standard value (theoretically, when traveling straight, the cylinder is in the center position, and the fourth rotation angle is 0° or a specific angle corresponding to the center position), the current deviation is recorded. ③ Calibration and adjustment: The control module calculates the displacement that the electric power steering cylinder needs to adjust based on the deviation, sends a control signal to the electric power steering cylinder, and drives the piston to move to the standard center position, completing the center-position calibration. Center-position calibration ensures that subsequent steering operations are based on an accurate center position, avoiding steering deviation due to initial position deviation.

[0044] In some optional implementations, limit position calibration is used to determine the maximum extension and retraction positions of the electric power steering cylinder to prevent it from exceeding its safe operating range. The specific operation is as follows: ① Limit test triggering: The control module first controls the electric power steering cylinder to extend slowly, while simultaneously monitoring the cylinder position sensor data and the fourth angle sensor data in real time. When the second wheel reaches its maximum steering angle (i.e., the vehicle's designed steering limit), and the fourth rotation angle reaches a preset maximum angle threshold, the control module records the cylinder position at this time as the maximum extension limit position. ② Reverse test: The electric power steering cylinder is controlled to retract, and the above monitoring process is repeated. When the second wheel reaches the maximum steering angle on the other side, the cylinder position at this time is recorded as the maximum retraction limit position. ③ Data storage and verification: The maximum extension and retraction position data are stored in the control module's memory and subjected to multiple tests for verification to ensure the accuracy and consistency of the limit position data. Limit position calibration not only protects the electric power steering cylinder and steering system components but also provides boundary conditions for subsequent power steering adjustments.

[0045] In some optional implementations, after completing the limit position calibration, the control module optimizes and adjusts the second steering assist based on the limit position data to improve steering performance and safety. For example, optimization can be based on the assist curve: the control module re-plans the output curve of the second steering assist based on the limit position. When approaching the limit position (maximum or minimum position), the assist output is appropriately reduced, allowing the driver to more clearly perceive steering resistance and avoid oversteering due to excessive assistance; while within the normal steering range, a reasonable assist output is maintained to ensure easy steering. Alternatively, a safety threshold can be set: based on the limit position, a safety threshold for the assist output is set. When the second wheel approaches the limit steering angle, if the control module detects abnormal steering force or speed changes, it will limit the assist output of the electric power steering cylinder, or even cut off the assist, to prevent the risk of vehicle loss of control due to oversteering. Alternatively, adaptive adjustment can be used: combining vehicle driving conditions (such as vehicle speed, road conditions, etc.) and limit position data, the control module can dynamically adjust the second steering assist. For example, at high speeds, the assist adjustment is more conservative when approaching the limit position to enhance vehicle stability; at low speeds, the assist adjustment range is appropriately widened to improve steering agility. Through the above-mentioned mid-position calibration, limit position calibration and power assist adjustment process, the control module can accurately control the working state of the electric power assist cylinder, so that the second steering assist is highly matched with the vehicle's steering needs, thereby improving the vehicle's steering accuracy, safety and driving comfort.

[0046] In some alternative implementations, such as Figure 2 As shown, the steering control system also includes: a power supply module and a generator; wherein, the power supply module is an emergency battery connected to the generator, and the generator is connected to the electric steering gear and the electric power assist cylinder (e.g., Figure 2(As shown by the solid line in the middle), it is used to provide power to the electric steering system and the electric power assist cylinder.

[0047] The steering control system provided by this invention provides steering assistance to the corresponding main steering module and auxiliary steering module through an electric steering gear and an electric power steering cylinder, and is connected to a control module. The control module adjusts the corresponding steering assistance according to the operating status of the main steering module and auxiliary steering module. This invention, through electric steering control, can flexibly adjust the steering assistance according to the steering conditions, solving the problem of unmanageable backlash during transmission, improving transmission accuracy and efficiency, and enabling the driver's steering operations to be transmitted to the wheels instantly and accurately, significantly improving the precision and sensitivity of handling.

[0048] The present invention also provides a vehicle, such as a wheeled crane or other engineering vehicle, comprising: a frame and the above-mentioned... Figure 1 The steering control system shown is provided, and the frame includes a first wheel and a second wheel.

[0049] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A steering control system, comprising: A main steering module, an auxiliary steering module, and a control module, characterized in that the control module is connected to the electric steering gear of the main steering module and to the electric power steering cylinder of the auxiliary steering module, wherein... The electric steering system is used to provide first steering assistance to the main steering module; The electric power steering cylinder is used to provide a second steering assist to the auxiliary steering module; The control module is connected to the electric steering gear and the electric power assist cylinder, and is used to adjust the first steering assist according to the steering status of the main steering module, and / or adjust the second steering assist according to the steering status of the auxiliary steering module. The main steering module further includes: a steering wheel, a steering column, an angle transmission, a steering drive shaft, a steering drop arm, a first steering tie rod, a first steering drive axle, a first angle sensor, a second angle sensor, a third angle sensor, and a torque sensor. The steering wheel, steering column, angle transmission, steering drive shaft, steering drop arm, electric steering gear, first steering tie rod, and first steering drive axle are sequentially connected and arranged to drive the first wheel corresponding to the first steering drive axle to steer according to the steering force acting on the steering wheel and the first steering assist. The first angle sensor is arranged at the input end of the steering column to monitor the first rotation angle and rotation angular velocity of the steering wheel; The second angle sensor is deployed on the electric steering gear to monitor the second rotation angle of the electric steering gear input shaft; The torque sensor is deployed on the electric steering gear to monitor the current torque of the electric steering gear input shaft; The third angle sensor is deployed on the first steering drive axle to monitor the third rotation angle of the first wheel; The control module is connected to the first angle sensor, the second angle sensor, and the torque sensor. Adjusting the first steering assist based on the steering status of the main steering module includes: The system acquires the first rotation angle, the rotation angular velocity, the second rotation angle, the current torque, and the current vehicle speed, and acquires a pre-determined standard steering assist curve and a compensated steering assist curve. Calculate the first angle difference between the first rotation angle and the second rotation angle. If the first angle difference is less than or equal to a first preset angle threshold, then determine the first steering assist based on the current torque, the current vehicle speed, and the standard steering assist curve. If the first angle difference is greater than the first preset angle threshold, then the first steering assist is determined based on the rotational angular velocity, the current torque, the current vehicle speed, and the compensated steering assist curve.

2. The system according to claim 1, characterized in that, The auxiliary steering module also includes: a steering rocker arm, a second steering tie rod, a second steering drive axle, and a fourth angle sensor; The electric power steering cylinder, the steering rocker arm, the second steering tie rod, and the second steering drive axle are connected in sequence to drive the second wheel corresponding to the second steering drive axle to steer according to the steering force acting on the steering wheel and the second steering assist. The fourth angle sensor is deployed on the second steering drive axle to monitor the fourth rotation angle of the second wheel.

3. The system according to claim 2, characterized in that, The control module is connected to the third angle sensor and the fourth angle sensor. Adjusting the second steering assist based on the steering status of the auxiliary steering module includes: Obtain the third rotation angle and the fourth rotation angle; Based on a predetermined wheel rotation angle relationship function, the theoretical rotation angle of the second wheel is determined according to the third rotation angle; Calculate the second angle difference between the third rotation angle and the theoretical rotation angle. If the second angle difference is less than or equal to the second preset angle threshold, then determine that the second steering assist is a preset value. If the second angle difference is greater than the second preset angle threshold, then adjust the second steering assist until the second angle difference is less than or equal to the second preset angle threshold.

4. The system according to claim 2, characterized in that, The electric power-assisted cylinder is also equipped with a stroke sensor; The stroke sensor is used to monitor the position of the hydraulic cylinder of the electric power-assisted cylinder and send the position of the hydraulic cylinder to the control module; The control module performs mid-position calibration and limit position calibration of the electric power steering cylinder based on the cylinder position and the fourth rotation angle, and adjusts the second steering assist based on the limit position calibration.

5. The system according to claim 4, characterized in that, The adjustment of the second steering assist based on the extreme position calibration includes: If, after the electric power steering cylinder responds to the second steering assist, the position of the cylinder exceeds the maximum or minimum position calibrated after the limit position is set, then the second steering assist is reduced.

6. The system according to claim 2, characterized in that, One end of the electric power-assisted cylinder is connected to the vehicle frame, and the other end is connected to the steering rocker arm, and is located on the side of the vehicle frame.

7. The system according to claim 1, characterized in that, Also includes: Power supply module and generator; The power supply module is connected to the generator, and the generator is connected to the electric steering gear and the electric power assist cylinder, for providing power to the electric steering gear and the electric power assist cylinder.

8. A vehicle, characterized in that, include: A vehicle frame and a steering control system according to any one of claims 1 to 7, wherein the vehicle frame includes a first wheel and a second wheel.

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