Control method and control system for steering oil pump of vehicle and vehicle

Abstract

The invention provides a control method and system for a steering oil pump of a vehicle and the vehicle. The control method comprises the steps that the current vehicle speed of the vehicle and the current angular speed of a steering wheel are obtained, and whether the current angular speed of the steering wheel reaches an angular speed triggering threshold value of a vehicle speed interval where the current vehicle speed of the vehicle is located or not is judged; when the current angular speed of the steering wheel reaches an angular speed triggering threshold value of a vehicle speed interval where the current vehicle speed of the vehicle is located, according to the corresponding relation between the vehicle speed interval of the vehicle and the operation parameters of a steering oil pump, the operation parameters corresponding to the vehicle speed interval where the current vehicle speed of the vehicle is located are determined to serve as target operation parameters; wherein the operation parameters comprise the motor output power and the motor rotating speed of the steering oil pump. And controlling the steering oil pump to rotate according to the target operating parameters. The vehicle speed is divided into a plurality of vehicle speed intervals, the corresponding vehicle speed intervals are matched according to the current vehicle speed of the vehicle, the operation parameters of the steering oil pump are dynamically adjusted, stepped adjustment of the rotating speed of the steering oil pump is achieved, and energy consumption is remarkably reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobiles, in particular to a control method and system for a steering oil pump of a vehicle and the vehicle. BACKGROUND

[0002] As the core component of vehicle control, the evolution of automobile steering system is directly related to driving safety, comfort and energy efficiency. From the early mechanical steering system to hydraulic power steering system (HPS), then to electric hydraulic power steering system (EHPS) and electric power steering system (EPS), and finally to the emerging steer-by-wire system (SBW), each iteration aims to solve the inherent defects of the previous system. Although the traditional hydraulic power steering system can amplify the steering force through hydraulic pressure, its high energy consumption, response lag and inability to achieve dynamic power adjustment have become increasingly prominent. The introduction of electronic control technology enables the EHPS system to adjust the power characteristics according to the vehicle speed signal, but it still has the following limitations: The traditional EHPS system adjusts the oil pressure through the electromagnetic valve to achieve variable power, but the continuous operation of the oil pump leads to engine power loss. For example, when a vehicle is driving straight at high speed, the steering oil pump still works at a fixed speed, causing unnecessary energy waste and leading to insufficient energy efficiency optimization. SUMMARY

[0003] The present application provides a control method and system for a steering oil pump of a vehicle and the vehicle, which significantly reduces energy consumption.

[0004] In a first aspect, the present application provides a control method for a steering oil pump of a vehicle, comprising: obtaining the current speed of the vehicle and the current angular velocity of the steering wheel, and determining whether the current angular velocity of the steering wheel reaches the angular velocity trigger threshold of the speed interval in which the current speed of the vehicle is located; when the current angular velocity of the steering wheel reaches the angular velocity trigger threshold of the speed interval in which the current speed of the vehicle is located, determining the running parameter corresponding to the speed interval in which the current speed of the vehicle is located as the target running parameter according to the corresponding relationship between the speed interval of the vehicle and the running parameter of the steering oil pump; wherein the running parameter includes the motor output power and the motor speed of the steering oil pump; controlling the steering oil pump to rotate at the target running parameter.

[0005] Further, the number of speed intervals of the vehicle is multiple, each of the speed intervals includes multiple groups of running parameters, each group of running parameters includes the corresponding motor output frequency and motor speed of the steering oil pump, and the corresponding relationship of the motor output frequency and motor speed of the steering oil pump in different groups of running parameters is different; the control of the steering oil pump to rotate at the target running parameter comprises: determining whether the current vehicle speed exceeds a set speed, when the current vehicle speed is not greater than the set speed, determining a vehicle speed interval corresponding to the current vehicle speed, and determining a set of operation parameters closest to the current motor output frequency and motor speed of the steering oil pump from the multiple sets of operation parameters as the closest operation parameters; controlling the operation parameters of the steering oil pump to gradually decrease from the closest operation parameters.

[0006] Further, the number of vehicle speed intervals is six, including a first interval, a second interval, a third interval, a fourth interval, a fifth interval, and a sixth interval. The vehicle speed range of the first interval is 0-3km / h. The vehicle speed range of the second interval is 3-20km / h. The vehicle speed range of the third interval is 20-40km / h. The vehicle speed range of the fourth interval is 40-60km / h. The vehicle speed range of the fifth interval is 60-80km / h. The vehicle speed range of the sixth interval is greater than 80km / h.

[0007] Further, the number of operation parameters of the first interval is four, including a first operation parameter, a second operation parameter, a third operation parameter, and a fourth operation parameter; the motor output frequency of the steering oil pump of the first operation parameter is 73.33HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the second operation parameter is 60.7HZ, and the motor speed is 910r / min; the motor output frequency of the steering oil pump of the third operation parameter is 49HZ, and the motor speed is 735r / min; the motor output frequency of the steering oil pump of the fourth operation parameter is 28.7HZ, and the motor speed is 430r / min; and / or The number of operation parameters of the second interval is two, including a fifth operation parameter and a sixth operation parameter; the motor output frequency of the steering oil pump of the fifth operation parameter is 73.3HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the sixth operation parameter is 68.7HZ, and the motor speed is 1030r / min; and / or The number of the operation parameters of the third interval is three groups, including a seventh operation parameter, an eighth operation parameter and a ninth operation parameter; the motor output frequency of the steering oil pump of the seventh operation parameter is 73.3HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the eighth operation parameter is 67.7HZ, and the motor speed is 1015r / min; the motor output frequency of the steering oil pump of the ninth operation parameter is 63.7HZ, and the motor speed is 955r / min; the motor output frequency of the steering oil pump of the fourth operation parameter is 28.7HZ, and the motor speed is 430r / min; and / or The number of the operation parameters of the fourth interval is three groups, including a tenth operation parameter, an eleventh operation parameter and a twelfth operation parameter; the motor output frequency of the steering oil pump of the tenth operation parameter is 73.3HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the eleventh operation parameter is 65HZ, and the motor speed is 975r / min; the motor output frequency of the steering oil pump of the twelfth operation parameter is 58HZ, and the motor speed is 870r / min; and / or The number of the operation parameters of the fifth interval is four groups, including a thirteenth operation parameter, a fourteenth operation parameter, a fifteenth operation parameter and a sixteenth operation parameter; the motor output frequency of the steering oil pump of the thirteenth operation parameter is 73.33HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the fourteenth operation parameter is 67.7HZ, and the motor speed is 1015r / min; the motor output frequency of the steering oil pump of the fifteenth operation parameter is 62.7HZ, and the motor speed is 940r / min; the motor output frequency of the steering oil pump of the sixteenth operation parameter is 53.3HZ, and the motor speed is 800r / min; and / or The number of the operation parameters of the sixth interval is four groups, including a seventeenth operation parameter, an eighteenth operation parameter, a nineteenth operation parameter and a twentieth operation parameter; the motor output frequency of the steering oil pump of the seventeenth operation parameter is 73.33HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the eighteenth operation parameter is 65HZ, and the motor speed is 975r / min; the motor output frequency of the steering oil pump of the nineteenth operation parameter is 58HZ, and the motor speed is 870r / min; the motor output frequency of the steering oil pump of the twentieth operation parameter is 48.3HZ, and the motor speed is 725r / min.

[0008] Further, the control method further comprises: acquiring the current angular velocity of the steering wheel, and judging the size relationship between the current angular velocity of the steering wheel and the set angular velocity; when the current angular velocity of the steering wheel is greater than the set angular velocity, the rotating speed of the steering oil pump is controlled to increase to a set rotating speed; when the current angular velocity of the steering wheel is less than or equal to the set angular velocity, the rotating speed of the motor of the steering oil pump is controlled to decrease step by step.

[0009] Further, the step-by-step decrease of the rotating speed of the motor of the steering oil pump comprises: According to the duration integral of the angular velocity of the steering wheel, the rotating speed of the motor of the steering oil pump is controlled to decrease step by step.

[0010] Further, the set angular velocity is 12° / s; and / or the set rotating speed is 1100r / min.

[0011] Further, there is a speed node between two adjacent speed intervals, and the control method further comprises: obtaining the current speed of the vehicle, and judging whether the difference between the current speed of the vehicle and the speed node between the two adjacent speed intervals closest to the current speed of the vehicle exceeds a set buffer threshold value; when the difference does not exceed the set buffer threshold value, the steering oil pump is controlled to maintain the current rotating speed of the motor; when the difference exceeds the set buffer threshold value, the steering oil pump is controlled to rotate at the rotating speed of the motor corresponding to the adjacent speed interval according to the driving trend of the vehicle; wherein the driving trend comprises an acceleration trend and a deceleration trend.

[0012] Further, the set buffer threshold value is the speed node between the two adjacent speed intervals ±5km / h.

[0013] Further, the steering oil pump has a basic motor output frequency and a basic motor rotating speed, and the control method further comprises: when the vehicle fails, the steering oil pump is controlled to operate at the basic motor output frequency and the basic motor rotating speed.

[0014] In a second aspect, an embodiment of the present application provides a control system configured to perform the control method of the first aspect.

[0015] In a third aspect, an embodiment of the present application provides a vehicle comprising the control system of the second aspect.

[0016] By the above technical solution, the speed is divided into multiple speed intervals, the corresponding speed interval is matched according to the current speed of the vehicle, the operating parameters of the steering oil pump are dynamically adjusted, the step-by-step adjustment of the rotating speed of the steering oil pump is realized, and the energy consumption is significantly reduced.

[0017] It should be understood that the foregoing general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. Attached Figure Description

[0018] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.

[0019] Figure 1 The diagram shows a flowchart of a control method for a vehicle's steering oil pump according to an exemplary embodiment of this application.

[0020] Figure 2 The diagram shown is an overall system flowchart of the control method for the steering oil pump of a vehicle according to an exemplary embodiment of this application.

[0021] Figure 3 The diagram shown is a flowchart of a control method for a vehicle's steering oil pump according to another exemplary embodiment of this application.

[0022] Figure 4 The diagram shown is a fault-tolerant processing flowchart of the control method for the steering oil pump of a vehicle according to an exemplary embodiment of this application. Detailed Implementation

[0023] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0024] This application provides a control method, control system, and vehicle for a vehicle's power steering pump. The control method, control system, and vehicle of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0025] See Figure 1 and Figure 2 As shown, this application embodiment provides a control method for a vehicle's steering pump. It should be noted that the following control methods can all be executed by the vehicle's SDCAC (Steering Pump Controller), which is a control module that provides steering assistance to the entire vehicle. The steering pump can be the vehicle's EHPS (Electro-Hydraulic Power Steering System). The control method includes steps S1-S3: Step S1, obtaining the current speed of the vehicle and the current angular velocity of the steering wheel, and determining whether the current angular velocity of the steering wheel reaches the angular velocity trigger threshold of the speed interval where the current speed of the vehicle is located. When the current angular velocity of the steering wheel does not reach the angular velocity trigger threshold, it indicates that the user's operation on the steering wheel does not have the demand for steering, and auxiliary assistance can not be provided. Alternatively, the vehicle speed acquisition can receive the vehicle speed signal of the ESP / ABS module through the CAN bus (period 10 ms). The angular velocity calculation can be based on the ESC_VDC2 steering wheel angle signal (period 20 ms), and the angular velocity is calculated through the formula conversion.

[0026] Step S2, when the current angular velocity of the steering wheel reaches the angular velocity trigger threshold of the speed interval where the current speed of the vehicle is located, it indicates that the user's operation on the steering wheel has the demand for steering. At this time, the corresponding running parameter of the speed interval where the current speed of the vehicle is located can be determined as the target running parameter according to the corresponding relationship between the speed interval of the vehicle and the running parameter of the steering oil pump; wherein the running parameter includes the motor output power and the motor speed of the steering oil pump. The running parameter corresponding to the speed interval and the angular velocity threshold of the steering wheel can be obtained by table lookup method. For example, the VCU dynamically adjusts the motor output frequency of the SDCA through table lookup to control the motor speed of the steering oil pump.

[0027] Step S3, controlling the steering oil pump to rotate at the target running parameter to realize the auxiliary assistance for the steering of the vehicle.

[0028] According to the above technical solution, the vehicle speed is divided into multiple speed intervals, and the corresponding basic frequency, basic speed and angular velocity trigger threshold of the steering oil pump motor are set for each speed interval. According to the current speed of the vehicle, the corresponding speed interval is matched, the motor output frequency and the motor speed of the steering oil pump motor are dynamically adjusted, the stepwise adjustment of the steering oil pump speed is realized, the energy consumption is significantly reduced, and the problem of high energy consumption under low speed working condition is solved. According to the double parameters of speed and angular velocity, the limitation of single threshold control is avoided, and the energy efficiency optimization and dynamic matching are realized.

[0029] In some optional embodiments, the number of speed intervals of the vehicle is multiple, each of the speed intervals includes multiple groups of running parameters, each group of running parameters includes the corresponding motor output frequency and motor speed of the steering oil pump, and the corresponding relationship of the motor output frequency and the motor speed of the steering oil pump in different groups of running parameters is different.

[0030] Referring to FIGS. 1, 2 and 3, Figure 2 and Figure 3 In the above step S3, the control of the steering oil pump to rotate at the target running parameter can further include steps S31-S32: Step S31, determining whether the current vehicle speed exceeds a set speed, when the current vehicle speed is not greater than the set speed, determining the vehicle speed interval corresponding to the current vehicle speed, and determining a set of running parameters closest to the current motor output frequency and motor speed of the steering oil pump from the multiple sets of running parameters as the closest running parameters.

[0031] Step S32, controlling the running parameters of the steering oil pump to gradually decrease from the closest running parameters. In this way, when the vehicle speed is low and in a low-speed working condition, the gradual decrease of the motor output frequency and motor speed of the steering oil pump can realize the gradual adjustment of the steering oil pump, and reduce the energy consumption in the low-speed working condition. At the same time, it can also avoid the influence of the stability of the vehicle driving due to the too large instantaneous change of the running parameters of the steering oil pump.

[0032] In some optional embodiments, the number of vehicle speed intervals is six, including a first interval, a second interval, a third interval, a fourth interval, a fifth interval and a sixth interval.

[0033] The speed range of the first interval is 0-3km / h; the speed range of the second interval is 3-20km / h; the speed range of the third interval is 20-40km / h; the speed range of the fourth interval is 40-60km / h; the speed range of the fifth interval is 60-80km / h; and the speed range of the sixth interval is greater than 80km / h. In this way, the vehicle speed is divided into six intervals, and different running parameter controls can be implemented on the steering oil pump according to different vehicle speeds, and the auxiliary assistance can be distributed as needed to reduce the energy consumption in the low-speed working condition.

[0034] In the present embodiment, the number of running parameters of the first interval is four, including a first running parameter, a second running parameter, a third running parameter and a fourth running parameter.

[0035] As shown in Table 1, the motor output frequency of the steering oil pump of the first running parameter is 73.33HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the second running parameter is 60.7HZ, and the motor speed is 910r / min; the motor output frequency of the steering oil pump of the third running parameter is 49HZ, and the motor speed is 735r / min; and the motor output frequency of the steering oil pump of the fourth running parameter is 28.7HZ, and the motor speed is 430r / min.

[0036] The number of the operation parameters of the second interval is two groups, including a fifth operation parameter and a sixth operation parameter; the motor output frequency of the steering oil pump of the fifth operation parameter is 73.3HZ, and the motor rotating speed is 1100r / min; the motor output frequency of the steering oil pump of the sixth operation parameter is 68.7HZ, and the motor rotating speed is 1030r / min.

[0037] The number of the operation parameters of the third interval is three groups, including a seventh operation parameter, an eighth operation parameter and a ninth operation parameter; the motor output frequency of the steering oil pump of the seventh operation parameter is 73.3HZ, and the motor rotating speed is 1100r / min; the motor output frequency of the steering oil pump of the eighth operation parameter is 67.7HZ, and the motor rotating speed is 1015r / min; the motor output frequency of the steering oil pump of the ninth operation parameter is 63.7HZ, and the motor rotating speed is 955r / min; the motor output frequency of the steering oil pump of the fourth operation parameter is 28.7HZ, and the motor rotating speed is 430r / min.

[0038] The number of the operation parameters of the fourth interval is three groups, including a tenth operation parameter, an eleventh operation parameter and a twelfth operation parameter; the motor output frequency of the steering oil pump of the tenth operation parameter is 73.3HZ, and the motor rotating speed is 1100r / min; the motor output frequency of the steering oil pump of the eleventh operation parameter is 65HZ, and the motor rotating speed is 975r / min; the motor output frequency of the steering oil pump of the twelfth operation parameter is 58HZ, and the motor rotating speed is 870r / min.

[0039] The number of the operation parameters of the fifth interval is four groups, including a thirteenth operation parameter, a fourteenth operation parameter, a fifteenth operation parameter and a sixteenth operation parameter; the motor output frequency of the steering oil pump of the thirteenth operation parameter is 73.33HZ, and the motor rotating speed is 1100r / min; the motor output frequency of the steering oil pump of the fourteenth operation parameter is 67.7HZ, and the motor rotating speed is 1015r / min; the motor output frequency of the steering oil pump of the fifteenth operation parameter is 62.7HZ, and the motor rotating speed is 940r / min; the motor output frequency of the steering oil pump of the sixteenth operation parameter is 53.3HZ, and the motor rotating speed is 800r / min.

[0040] The number of operation parameters of the sixth interval is four groups, including a seventeenth operation parameter, an eighteenth operation parameter, a nineteenth operation parameter, and a twentieth operation parameter; the motor output frequency of the steering oil pump of the seventeenth operation parameter is 73.33HZ, and the motor speed is 1100r / min; the motor output frequency of the steering oil pump of the eighteenth operation parameter is 65HZ, and the motor speed is 975r / min; the motor output frequency of the steering oil pump of the nineteenth operation parameter is 58HZ, and the motor speed is 870r / min; and the motor output frequency of the steering oil pump of the twentieth operation parameter is 48.3HZ, and the motor speed is 725r / min.

[0041] Table 1 Therefore, the vehicle speed is divided into multiple vehicle speed intervals, the corresponding vehicle speed interval is matched according to the current vehicle speed of the vehicle, the motor output frequency and the motor speed of the motor of the steering oil pump are dynamically adjusted, the step-by-step adjustment of the steering oil pump speed is realized, the energy consumption is significantly reduced, and the problem of high energy consumption in the low-speed working condition is solved. When the vehicle speed is low and in the low-speed working condition, the step-by-step adjustment of the steering oil pump can be realized by gradually reducing the motor output frequency and the motor speed of the steering oil pump, the energy consumption in the low-speed working condition is reduced, the energy efficiency optimization and dynamic matching are realized. At the same time, the influence of the stability of the vehicle driving caused by the too large instantaneous change of the operation parameters of the steering oil pump can also be avoided.

[0042] In some optional embodiments, the control method further comprises: acquiring the current angular velocity of the steering wheel, and judging the size relationship between the current angular velocity of the steering wheel and the set angular velocity. When the current angular velocity of the steering wheel is greater than the set angular velocity, the motor speed of the steering oil pump is controlled to be raised to the set speed. When the current angular velocity of the steering wheel is less than or equal to the set angular velocity, the motor speed of the steering oil pump is controlled to be gradually reduced. Optionally, the set angular velocity is 12° / s, and the set speed is 1100r / min.

[0043] Therefore, the operation of the steering wheel is divided into two types of slow operation and sharp turning operation, the case that the angular velocity of the steering wheel is less than or equal to 12° / s is defined as the slow operation, and the case that the angular velocity of the steering wheel is greater than 12° / s is defined as the sharp turning operation. The size relationship between the angular velocity of the steering wheel and the 12° / s threshold value is compared in real time, for the sharp turning operation, the motor speed of the steering oil pump is immediately raised to 1100r / min, the response speed is improved, the delay of the assistance during the sharp turning operation is shortened to within 80ms, which is better than the response of the traditional system of 100ms. For the slow operation, the motor speed of the steering oil pump is controlled to be gradually reduced, and the energy consumption is reduced.

[0044] In the embodiment, the control method comprises: controlling the operating parameters of the steering oil pump to gradually decrease, including: controlling the operating parameters of the steering oil pump to gradually decrease according to the time integral of the angular velocity of the steering wheel. In this way, the duration of the timed cumulative slow operation is used to trigger different levels of frequency reduction. For example, when the angular velocity is less than or equal to 12° / s, the frequency is reduced to 61.7HZ for 1 minute, to 49H for 2 minutes, and to 28.7H for 3 minutes. When the angular velocity is greater than 12° / s, the motor speed of the steering oil pump is immediately increased to 1100r / min. The timer is reset when the steering operation is rapid or the vehicle speed changes. In this way, four levels of frequency reduction are achieved through time integral, the energy consumption of low-speed operation is reduced by more than 23%, the timed cumulative slow operation duration is used to trigger different levels of frequency reduction, false triggering is avoided, the operation intention recognition function is achieved, and dynamic hysteresis compensation and vehicle speed node buffering are achieved.

[0045] Existing systems are mostly based on segmented control of vehicle speed and steering wheel angle, but do not fully consider the difference in power assistance demand caused by the speed of the steering wheel operation. For example, when steering at low speed and large angle, the system may not have enough steering force due to response delay, causing dynamic response lag.

[0046] Based on the above problems, in some optional embodiments, there is a vehicle speed node between two adjacent vehicle speed intervals, for example, the vehicle speed range of the second interval is 3-20km / h, and the vehicle speed range of the third interval is 20-40km / h. The vehicle speed node between the two is 20km / h. Similarly, the nodes between other vehicle speed intervals are 40km / h, 60km / h, and 80km / h.

[0047] The control method further comprises: obtaining the current vehicle speed, determining whether the difference between the current vehicle speed and the vehicle speed node between the two adjacent vehicle speed intervals closest to the current vehicle speed exceeds a set buffer threshold. When the difference does not exceed the set buffer threshold, the steering oil pump is controlled to maintain the current motor speed. When the difference exceeds the set buffer threshold, the steering oil pump is controlled to rotate at the motor speed corresponding to the adjacent vehicle speed interval according to the driving trend of the vehicle; wherein the driving trend includes acceleration trend and deceleration trend. Optionally, the set buffer threshold is ±5km / h. The original vehicle speed signal can be subjected to first-order low-pass filtering to obtain the vehicle speed.

[0048] Thus, by setting acceleration / deceleration buffer zones of ±5 km / h at speed nodes, frequent frequency switching due to speed fluctuations is avoided. For example, assuming the current speed is 19 km / h, in the second zone, when the vehicle accelerates, the speed must exceed (20+5) km / h, i.e., 25 km / h, before switching to the next zone, i.e., the third zone. Similarly, assuming the current speed is 21 km / h, in the third zone, when the vehicle decelerates, the speed must fall below (20-5) km / h, i.e., 15 km / h, before switching to the previous zone, i.e., the second zone. This reduces control oscillations caused by speed fluctuations. The speed node buffer mechanism reduces control oscillations, improving driving comfort by 15%.

[0049] In existing technologies, when CAN communication is abnormal or components fail, traditional systems lack reliable degradation control strategies, which may lead to a complete loss of power steering, endangering driving safety, and lacking fault tolerance mechanisms.

[0050] Based on the above issues, see Figure 2 and Figure 4 As shown, in some optional embodiments, the power steering pump has a base motor output frequency and a base motor speed, and the control method further includes: controlling the power steering pump to operate at the base motor output frequency and the base motor speed when a vehicle malfunctions. Optionally, the base motor output frequency is 73.3 Hz.

[0051] Vehicle malfunctions can include communication loss, component failure, etc. When communication is lost, i.e., when the SDCAC detects a loss of VCU messages, the SDCAC can force the steering pump to operate at a base motor output frequency of 73.3Hz, and the VCU (Vehicle Domain Controller) continues to send default commands. When a component fails, i.e., an internal SDCAC failure, a tiered alarm is triggered via a hardware watchdog. The SDCAC performs the following actions based on the fault level: a red light for a level 3 fault, a yellow light for a level 2 fault, and continues operation for a level 1 fault. Level 3 fault tolerance ensures that the steering system can still provide basic power steering in extreme situations. Automatic recovery function: Automatically switches to normal control logic after the fault is cleared, without manual intervention. This improves vehicle safety: ensuring that the steering system can still provide basic power steering in extreme situations, avoiding the risk of loss of control. Redundant control strategies ensure that the steering system can still provide basic power steering in the event of communication abnormalities or component failures. This achieves a level 3 fault tolerance and self-recovery mechanism.

[0052] The control scheme for the power steering pump of the vehicle in this application has the following beneficial effects: (1) Control dimensions: vehicle speed + steering wheel angular velocity + duration (four-level frequency reduction is achieved by integrating angular velocity and duration, making energy efficiency optimization more refined). (2) Energy efficiency optimization: multi-stage dynamic frequency adjustment, energy consumption reduction of 23% in low-speed working conditions (experimental data shows that the energy consumption reduction rate in the 0-3 km / h range is increased by 8%) (3) Response speed: real-time angular velocity identification (20 ms cycle), response time ≤ 80 ms (response speed of sharp turning operation is increased by more than 20%).

[0053] (4) Fault tolerance: forced basic frequency + hierarchical alarm + self-recovery (communication abnormality can still maintain basic steering function, higher safety).

[0054] (5) Dynamic matching: angular velocity grading + time integral frequency reduction (more accurate identification of sharp turning operation, lower energy consumption of slow turning operation).

[0055] (6) System stability: set 5 km / h vehicle speed node buffer (reduce control oscillation, improve driving comfort).

[0056] The present application solves the problems of energy efficiency, response and fault tolerance of the traditional EHPS system through four innovations of multi-stage dynamic frequency adjustment, angular velocity intelligent identification, dynamic hysteresis compensation and three-level fault tolerance. The present application has significant advantages in energy efficiency optimization, response speed, fault tolerance and system stability, and provides a more efficient, safe and intelligent solution for the electric hydraulic power steering system.

[0057] The present application also provides a control system configured to perform the control method of the steering oil pump of the vehicle as described in the above embodiments and implementation manners. In this way, the motor output frequency and motor speed of the motor of the steering oil pump are dynamically adjusted according to the matching of the corresponding vehicle speed interval to the current vehicle speed of the vehicle, the stepwise regulation of the steering oil pump speed is realized, the energy consumption is significantly reduced, and the problem of excessive energy consumption in low-speed working conditions is solved. According to the double parameters of vehicle speed and angular velocity, the assistance is adjusted, the limitation of single threshold control is avoided, and energy efficiency optimization and dynamic matching are realized.

[0058] The present application provides a vehicle comprising the control system as described in the above embodiments and implementation manners. In this way, the motor output frequency and motor speed of the motor of the steering oil pump are dynamically adjusted according to the matching of the corresponding vehicle speed interval to the current vehicle speed of the vehicle, the stepwise regulation of the steering oil pump speed is realized, the energy consumption is significantly reduced, and the problem of excessive energy consumption in low-speed working conditions is solved. According to the double parameters of vehicle speed and angular velocity, the assistance is adjusted, the limitation of single threshold control is avoided, and energy efficiency optimization and dynamic matching are realized.

[0059] It should be understood that the present application is not limited to the precise construction which has been described above and illustrated in the accompanying drawings, and that various modifications and changes can be made without departing from the scope thereof. The scope of the application is limited only by the appended claims.

Claims

1. A method for controlling a vehicle's power steering pump, characterized in that, include: Get the vehicle's current speed and the steering wheel's current angular velocity, and determine whether the steering wheel's current angular velocity has reached the angular velocity trigger threshold of the vehicle's current speed range. When the current angular velocity of the steering wheel reaches the angular velocity trigger threshold of the vehicle speed range where the current vehicle speed is located, the operating parameters corresponding to the vehicle speed range where the current vehicle speed is located are determined according to the correspondence between the vehicle speed range and the operating parameters of the steering pump, and are used as the target operating parameters; wherein, the operating parameters include the motor output power and motor speed of the steering pump. Control the steering pump to rotate at the target operating parameters.

2. The control method according to claim 1, characterized in that, The vehicle has multiple speed ranges, and each speed range includes multiple sets of operating parameters. Each set of operating parameters includes the motor output frequency and motor speed of the corresponding steering pump. The correspondence between the motor output frequency and motor speed of the steering pump is different for different sets of operating parameters. The control of the steering pump to rotate at the target operating parameters includes: Determine whether the current vehicle speed exceeds the set speed. If the current vehicle speed is not greater than the set speed, determine the speed range corresponding to the current vehicle speed. From the multiple sets of operating parameters, determine the set of operating parameters that is closest to the current motor output frequency and motor speed of the steering oil pump, and use it as the closest operating parameter. The operating parameters of the steering pump are gradually reduced from the closest operating parameter.

3. The control method according to claim 2, characterized in that, The number of speed ranges is six, including the first range, the second range, the third range, the fourth range, the fifth range, and the sixth range; The speed range for the first section is 0-3 km / h; The speed range for the second section is 3-20 km / h; The speed range for the third section is 20-40 km / h; The speed range for the fourth section is 40-60 km / h; The speed range for the fifth section is 60-80 km / h; The speed range in the sixth section is greater than 80 km / h.

4. The control method according to claim 3, characterized in that, The first interval has four sets of operating parameters, including a first operating parameter, a second operating parameter, a third operating parameter, and a fourth operating parameter; the motor output frequency of the steering pump in the first operating parameter is 73.33 Hz, and the motor speed is 1100 r / min; the motor output frequency of the steering pump in the second operating parameter is 60.7 Hz, and the motor speed is 910 r / min; the motor output frequency of the steering pump in the third operating parameter is 49 Hz, and the motor speed is 735 r / min; the motor output frequency of the steering pump in the fourth operating parameter is 28.7 Hz, and the motor speed is 430 r / min; and / or The second interval has two sets of operating parameters, including a fifth operating parameter and a sixth operating parameter; the fifth operating parameter has a steering pump motor output frequency of 73.3 Hz and a motor speed of 1100 r / min; the sixth operating parameter has a steering pump motor output frequency of 68.7 Hz and a motor speed of 1030 r / min; and / or The third interval has three sets of operating parameters, including a seventh operating parameter, an eighth operating parameter, and a ninth operating parameter; the seventh operating parameter has a motor output frequency of 73.3 Hz and a motor speed of 1100 r / min; the eighth operating parameter has a motor output frequency of 67.7 Hz and a motor speed of 1015 r / min; the ninth operating parameter has a motor output frequency of 63.7 Hz and a motor speed of 955 r / min; the fourth operating parameter has a motor output frequency of 28.7 Hz and a motor speed of 430 r / min; and / or The fourth interval has three sets of operating parameters, including the tenth, eleventh, and twelfth operating parameters; the tenth operating parameter has a motor output frequency of 73.3 Hz and a motor speed of 1100 r / min; the eleventh operating parameter has a motor output frequency of 65 Hz and a motor speed of 975 r / min; the twelfth operating parameter has a motor output frequency of 58 Hz and a motor speed of 870 r / min; and / or The fifth interval has four sets of operating parameters, including the thirteenth, fourteenth, fifteenth, and sixteenth operating parameters; the motor output frequency of the steering pump in the thirteenth operating parameter is 73.33 Hz, and the motor speed is 1100 r / min; the motor output frequency of the steering pump in the fourteenth operating parameter is 67.7 Hz, and the motor speed is 1015 r / min; the motor output frequency of the steering pump in the fifteenth operating parameter is 62.7 Hz, and the motor speed is 940 r / min; the motor output frequency of the steering pump in the sixteenth operating parameter is 53.3 Hz, and the motor speed is 800 r / min; and / or The number of operating parameters in the sixth interval is four sets, including the seventeenth operating parameter, the eighteenth operating parameter, the nineteenth operating parameter, and the twentieth operating parameter; The seventeenth operating parameter specifies that the motor output frequency of the steering pump is 73.33 Hz and the motor speed is 1100 r / min; the eighteenth operating parameter specifies that the motor output frequency of the steering pump is 65 Hz and the motor speed is 975 r / min; the nineteenth operating parameter specifies that the motor output frequency of the steering pump is 58 Hz and the motor speed is 870 r / min; and the twentieth operating parameter specifies that the motor output frequency of the steering pump is 48.3 Hz and the motor speed is 725 r / min.

5. The control method according to claim 1, characterized in that, The control method further includes: Get the current angular velocity of the steering wheel and determine the relationship between the current angular velocity and the set angular velocity; When the current angular velocity of the steering wheel is greater than the set angular velocity, the motor speed of the steering oil pump is increased to the set speed. When the current angular velocity of the steering wheel is less than or equal to the set angular velocity, the motor speed of the steering oil pump is controlled to decrease step by step.

6. The control method according to claim 5, characterized in that, The motor speed controlling the steering pump decreases in stages, including: Based on the integral of the duration of the steering wheel's angular velocity, the motor speed of the steering oil pump is controlled to decrease step by step.

7. The control method according to claim 6, characterized in that, The set angular velocity is 12° / s; and / or The set rotational speed is 1100 r / min.

8. The control method according to claim 1, characterized in that, The control method further includes a speed node between two adjacent speed ranges: Get the vehicle's current speed and determine whether the difference between the vehicle's current speed and the speed node between the two closest adjacent speed intervals exceeds the set buffer threshold. When the difference does not exceed the set buffer threshold, the steering oil pump is controlled to maintain the current motor speed. When the difference exceeds the set buffer threshold, the steering pump is controlled to rotate at the motor speed corresponding to the adjacent vehicle speed range according to the vehicle's driving trend; wherein, the driving trend includes acceleration trend and deceleration trend.

9. The control method according to claim 8, characterized in that, The set buffer threshold is ±5 km / h between two adjacent speed ranges.

10. The control method according to claim 1, characterized in that, The power steering pump has a base motor output frequency and a base motor speed, and the control method further includes: When a vehicle malfunctions, the steering pump is controlled to operate at the output frequency and speed of the base motor.

11. A control system, characterized in that, The control system is configured to perform the control method as described in any one of claims 1-10.

12. A vehicle, characterized in that, include: The control system as described in claim 11.

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