A power steering system for a vehicle, a control method thereof, and a vehicle

Abstract

The application discloses a steering assist system of a vehicle, a control method thereof and the vehicle. The method adopts a dual-energy driving assist steering scheme, that is, when a high-pressure steering oil pump motor controller is normal, the steering assist is performed by driving an oil pump motor by the high-pressure steering oil pump motor controller, and when the high-pressure steering oil pump motor controller cannot work normally, the steering assist is performed by driving the oil pump motor by a low-pressure steering oil pump motor controller. In the process of driving the oil pump motor to perform the steering assist, when an energy-saving mode condition is met, the running state of the corresponding oil pump motor controller is controlled to save energy. Thus, the application adopts the dual-energy driving assist steering scheme, sets up safety redundancy, improves control reliability, and when the dual-energy driving assist steering process is performed and the energy-saving mode condition is met, the energy-saving mode is entered, and the corresponding oil pump motor controller is turned off to save energy, so that the energy consumption economy of the steering assist system is considered while the safety of the steering assist is ensured.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a vehicle steering assist system and its control method, and a vehicle. Background Technology

[0002] With the advancement of technology, most vehicles now have power steering, which improves driving safety. Power steering is generally achieved by the vehicle's power steering system, which mainly uses electro-hydraulic power steering. This is a steering technology that combines the reliability of traditional hydraulic power steering with the intelligence of electronic control. Its working principle can be summarized as "motor-driven, on-demand power supply, and intelligent adjustment".

[0003] Currently, most vehicles use a single high-pressure drive electro-hydraulic power steering system, where a high-pressure drive controller drives the oil pump motor to provide steering assistance. However, with this system, if the high-pressure drive controller malfunctions or experiences a severe high-pressure failure that forces it to shut down, the vehicle will completely lose power steering, posing a serious safety hazard. This indicates that current power steering systems have low reliability and safety. Furthermore, the high-pressure drive controller remains on throughout the power steering process, even when not in use, wasting energy. Summary of the Invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0005] Therefore, one objective of this invention is to propose a control method for a vehicle's power steering system. This method employs a dual-energy drive electro-hydraulic power steering pump motor control scheme. When the high-pressure power steering pump motor controller malfunctions, the low-pressure power steering pump motor controller is activated. This solves the safety problem caused by a single high-pressure drive electro-hydraulic power steering system failure. Because the dual-energy drive electro-hydraulic power steering pump motor control includes both a high-pressure and a low-pressure power steering pump motor controller, with safety redundancy, vehicles using this method exhibit high control reliability and good safety. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode, shutting down the corresponding pump motor controller to conserve energy. Thus, while ensuring safe driving with power steering, the energy efficiency of the power steering system is also considered.

[0006] Therefore, another object of the present invention is to provide a vehicle steering assist system.

[0007] Therefore, another object of the present invention is to provide a vehicle.

[0008] To achieve the above objectives, a first aspect of the present invention provides a control method for a vehicle's power steering system, comprising the following steps: in response to a successful high-voltage power-on of the vehicle, activating the high-voltage power steering pump motor controller and the vehicle's DC-DC converter; when the high-voltage power steering pump motor controller is successfully activated, controlling the vehicle to travel at an unlimited speed, and during the operation of the power steering pump motor driven by the high-voltage power steering pump motor controller, when the vehicle meets the conditions for activating the power steering pump motor's energy-saving mode, saving energy consumption by controlling the operating state of the high-voltage power steering pump motor controller; and when the high-voltage power steering pump motor controller is activated... If the pump motor controller fails to start, it determines whether the DC-DC converter has started successfully and issues a prompt message indicating a high-pressure power steering failure. If yes, the low-pressure power steering pump motor controller is started; otherwise, a prompt message indicating a DC-DC converter failure is issued. If the low-pressure power steering pump motor controller starts successfully, the vehicle is controlled to travel at an unlimited speed. During the operation of the power steering pump motor driven by the low-pressure power steering pump motor controller, when the vehicle meets the conditions for activating the power steering pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the low-pressure power steering pump motor controller.

[0009] The vehicle steering assist system control method according to embodiments of the present invention employs a dual-energy drive electro-hydraulic steering pump motor control scheme. When the high-pressure steering pump motor controller malfunctions, the low-pressure steering pump motor controller is activated, solving the safety problem caused by a single high-pressure drive electro-hydraulic steering assist system failure. Because the dual-energy drive electro-hydraulic steering pump motor control includes both a high-pressure and a low-pressure steering pump motor controller with safety redundancy, vehicles using this method exhibit high control reliability and good safety. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode, shutting down the corresponding pump motor controller to conserve energy. Thus, while ensuring safe driving with power steering, the energy efficiency of the power steering system is also considered.

[0010] In addition, the control method for the vehicle steering assist system of the above embodiments of the present invention may also have the following additional technical features: In some embodiments, when the vehicle meets the conditions for activating the oil pump motor energy-saving mode, saving energy by controlling the operating state of the high-pressure power steering pump motor controller includes: controlling the high-pressure power steering pump motor controller to stop driving the oil pump motor to save energy.

[0011] In some embodiments, when the vehicle meets the conditions for activating the oil pump motor energy-saving mode, saving energy by controlling the operating state of the low-pressure power steering pump motor controller includes: controlling the low-pressure power steering pump motor controller to stop driving the oil pump motor to save energy.

[0012] In some embodiments, the method further includes: when it is determined that the low-pressure power steering pump motor controller fails to start, controlling the maximum speed of the vehicle to be limited to a preset safe speed.

[0013] In some embodiments, the conditions for activating the oil pump motor energy-saving mode include: the duration for which the vehicle remains in a preset state exceeds a preset time threshold, the preset state including: the vehicle is in a first preset gear, the transmission is in a second preset gear, the parking function is activated, and the wheel speed signals of all wheels are preset values.

[0014] In some embodiments, when the DC-DC converter fails to start, the method further includes: when it is determined that the vehicle has a driving demand, starting the low-pressure power steering pump motor controller; if the low-pressure power steering pump motor controller fails to start, controlling the maximum speed of the vehicle to be limited to no more than a preset safe speed, and issuing a prompt message to indicate a low-pressure power steering failure; if the low-pressure power steering pump motor controller starts successfully, identifying the type of the vehicle's low-pressure battery; and controlling the operating state of the vehicle according to the type of the low-pressure battery.

[0015] In some embodiments, controlling the vehicle's operating state based on the type of the low-voltage battery includes: when the low-voltage battery is determined to be a lithium battery, obtaining the current SOC of the low-voltage battery; if the current SOC is greater than or equal to a second preset SOC threshold and less than or equal to a first preset SOC threshold, controlling the vehicle to drive without speed limit and issuing a warning message indicating low-voltage drive steering and paying attention to driving safety; if the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, but the current SOC is greater than or equal to a third preset SOC threshold and less than or equal to a third preset SOC threshold, then... If the vehicle's maximum speed is limited to a preset safe speed, and the first preset SOC threshold is greater than the second preset SOC threshold, and the second preset SOC threshold is greater than the third preset SOC threshold, then if the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, and also not greater than or equal to the third preset SOC threshold and less than or equal to the second preset SOC threshold, then the vehicle's power output is prohibited to reduce the speed and maintain it at zero, and the battery management system is allowed to perform charge latching; or... When it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained. If the current voltage is greater than or equal to a second preset voltage threshold and less than or equal to a first preset voltage threshold, the vehicle is controlled to drive without speed limit, and a warning message indicating low-voltage drive steering and cautioning driving safety is issued. If the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, but is greater than or equal to a third preset voltage threshold and less than or equal to the second preset voltage threshold, the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset voltage threshold is greater than the second preset voltage threshold, and the second preset voltage threshold is greater than the third preset voltage threshold. If the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, and is not greater than or equal to the third preset voltage threshold and less than or equal to the second preset voltage threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

[0016] In some embodiments, after the low-pressure power steering pump motor controller fails to start, the maximum vehicle speed is limited to a preset safe speed, and a warning message indicating a low-pressure power steering malfunction is issued, the method further includes: when it is determined that the low-pressure battery is a lithium battery, obtaining the current SOC of the low-pressure battery; if the current SOC is less than or equal to a third preset SOC threshold, controlling the vehicle to prohibit power output so that the vehicle speed is reduced and maintained at zero, and allowing the battery management system to perform charge latching; or... When it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; if the current voltage is less than or equal to a third preset voltage threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

[0017] In some embodiments, the method further includes: in response to the failure of the high-voltage power-on, not activating the high-voltage power steering pump motor controller and the low-voltage power steering pump motor controller, and controlling the vehicle to disable power output; or, Before the vehicle is powered on at high voltage, the method further includes: in response to the successful power-on of the vehicle at low voltage, controlling the high-voltage power steering pump motor controller and the low-voltage power steering pump motor controller to perform a low-voltage self-test; if the low-voltage self-test result determines that the high-voltage power steering pump motor controller and / or the low-voltage power steering pump motor controller have a fault that prevents them from working, then issuing a corresponding prompt message to indicate a high-voltage power steering fault and / or a low-voltage power steering fault.

[0018] To achieve the above objectives, a second aspect of the present invention provides a vehicle power steering system, comprising: a hydraulic pump motor for power steering; a high-voltage power steering pump motor controller for driving the hydraulic pump motor; a low-voltage power steering pump motor controller for driving the hydraulic pump motor; and a controller configured to: activate the high-voltage power steering pump motor controller and the vehicle's DC-DC converter in response to a successful high-voltage power-on of the vehicle; control the vehicle to travel at an unlimited speed when the high-voltage power steering pump motor controller is successfully activated; and, during the operation of the hydraulic pump motor driven by the high-voltage power steering pump motor controller, when the vehicle meets the conditions for activating the power steering pump motor energy-saving mode, control the system to... The system describes the operating status of the high-pressure power steering pump motor controller to save energy. If the high-pressure power steering pump motor controller fails to start, it determines whether the DC-DC converter has started successfully and issues a warning message indicating a high-pressure power steering malfunction. If so, the low-pressure power steering pump motor controller is started; otherwise, a warning message indicating a DC-DC converter malfunction is issued. If the low-pressure power steering pump motor controller starts successfully, the vehicle is controlled to travel at an unlimited speed. Furthermore, during the operation of the power steering pump motor driven by the low-pressure power steering pump motor controller, when the vehicle meets the conditions for activating the power steering pump motor's energy-saving mode, energy consumption is saved by controlling the operating status of the low-pressure power steering pump motor controller.

[0019] The power steering system of the vehicle according to embodiments of the present invention employs a dual-energy drive electro-hydraulic power steering pump motor control scheme. When the high-pressure power steering pump motor controller malfunctions, the low-pressure power steering pump motor controller is activated, solving the safety problem caused by a single high-pressure drive electro-hydraulic power steering system failure. Because the dual-energy drive electro-hydraulic power steering pump motor control includes both a high-pressure and a low-pressure power steering pump motor controller with safety redundancy, vehicles using this system exhibit high control reliability and good safety. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode, shutting down the corresponding pump motor controller to save energy. Thus, while ensuring safe driving with power steering, the system also considers the energy efficiency of the power steering system.

[0020] To achieve the above objectives, a third aspect of the present invention provides a vehicle comprising: a steering assist system of the vehicle as described in the above embodiments of the present invention; or, the vehicle comprises: a processor, a memory, and a control program for the steering assist system of the vehicle stored in the memory and executable on the processor, wherein when the control program for the steering assist system of the vehicle is executed by the processor, it implements the control method for the steering assist system of the vehicle as described in the first aspect of the present invention.

[0021] According to embodiments of the present invention, the vehicle employs a dual-energy drive electro-hydraulic steering pump motor control scheme. When the high-pressure steering pump motor controller malfunctions, the low-pressure steering pump motor controller is activated, resolving the safety issues caused by a single high-pressure drive electro-hydraulic power steering system failure. Because the dual-energy drive electro-hydraulic steering pump motor control includes both a high-pressure and a low-pressure steering pump motor controller with safety redundancy, the vehicle exhibits high reliability and safety during power steering control. Furthermore, during dual-energy drive power steering, when energy-saving mode conditions are met, the vehicle enters energy-saving mode, shutting down the corresponding pump motor controller to conserve energy. Thus, while ensuring safe driving with power steering, the energy efficiency of the power steering system is also considered.

[0022] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0023] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 This is a flowchart of a control method for a vehicle's power steering system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the communication network architecture of a vehicle's power steering system according to a specific embodiment of the present invention. Figure 3 This is a schematic diagram of the power supply architecture of a vehicle's power steering system according to a specific embodiment of the present invention; Figure 4 This is a schematic diagram of the steering assist system of a vehicle according to an embodiment of the present invention. Detailed Implementation

[0024] To provide a more detailed understanding of the features and technical content of the embodiments of the present invention, the implementation of the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of the present invention. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be shown in a simplified manner to simplify the drawings.

[0025] The following is for reference. Figures 1-4 This invention describes a vehicle steering assist system and its control method, system, and vehicle according to embodiments of the present invention.

[0026] Figure 1This is a flowchart of a control method for a vehicle's power steering system according to an embodiment of the present invention. Figure 1 As shown, the control method of the vehicle's power steering system includes steps S1 to S5.

[0027] Step S1: In response to the successful power-on of the vehicle's high voltage, start the high-voltage power steering pump motor controller and the vehicle's DC-DC converter.

[0028] Specifically, when the vehicle is started, the vehicle will be powered on at low voltage and perform a self-test. After the low voltage power-on is successful, the vehicle will be powered on at high voltage. After the high voltage power-on is successful, the vehicle will start the high-voltage power steering pump motor controller and the vehicle's DC-DC converter.

[0029] Understandably, the high-pressure power steering pump motor controller drives the power steering pump motor to rotate, making steering wheel turning easy. If the high-pressure power steering pump motor controller is not activated, the pump motor will not rotate, posing a safety hazard to the vehicle. The vehicle's DC-DC converter acts as a "bridge" between the high-voltage and low-voltage systems, "stepping down" the high-voltage DC power into a stable low-voltage DC power to charge the battery and power all the vehicle's low-voltage electrical appliances. If the DC-DC converter does not activate or fails to activate successfully, the vehicle's low-voltage battery will quickly deplete, and without the high-voltage battery pack to provide range, a serious safety hazard will arise.

[0030] Step S2: When the high-pressure power steering pump motor controller starts successfully, control the vehicle to drive at an unlimited speed. During the operation of the power steering pump motor driven by the high-pressure power steering pump motor controller, when the vehicle meets the conditions for starting the power steering pump motor energy-saving mode, save energy by controlling the operating status of the high-pressure power steering pump motor controller.

[0031] Specifically, once the vehicle passes its self-check and the high-pressure power steering pump motor controller is successfully activated, the high-pressure power steering system is engaged. At this point, the vehicle has no speed limit, meaning it can travel at the driver's desired speed. Simultaneously, the high-pressure power steering pump motor controller drives the pump motor to provide steering assistance, facilitating steering. Further, during this driving process, the system determines whether the vehicle meets the conditions for activating the power steering pump motor's energy-saving mode. For example, if the gear shift lever is in neutral (N), the actual gearbox position is neutral (N), the handbrake is engaged, all wheel speed signals are 0 km / h, and this state persists for more than a set threshold, then the vehicle meets the conditions for activating the power steering pump motor's energy-saving mode. This indicates the vehicle is stationary and has no steering requirement. Therefore, the high-pressure power steering pump motor controller is controlled to stop driving the pump motor, thus entering power-saving mode. This solves the driving safety problem caused by the lack of power steering. At the same time, by judging the vehicle's status, when it is determined that the vehicle has no steering need based on whether the oil pump motor energy-saving mode is activated, the high-pressure steering oil pump motor controller is controlled to stop working. Thus, it can adaptively cut off the power to the high-pressure steering oil pump motor controller according to the actual working conditions, thereby achieving the effect of energy saving.

[0032] Step S3: If the high-pressure power steering pump motor controller fails to start, determine whether the DC-DC converter has started successfully and issue a prompt message to indicate a high-pressure power steering failure.

[0033] Specifically, if the high-pressure power steering pump motor controller fails to start, it indicates that the controller is not functioning properly and cannot provide effective power steering. A fault message indicating that the high-pressure power steering pump motor controller is not driving the power steering pump motor will be issued so that relevant personnel can be notified and address the issue promptly. To ensure driving safety, it is necessary to switch to the low-pressure power steering pump motor controller for power steering. The low-pressure power steering pump motor controller is powered by a low-pressure battery. The low-pressure battery uses a DC-DC converter to convert the high-voltage electricity from the battery pack into low-voltage DC power. Therefore, before switching, it is necessary to determine whether the DC-DC converter has started successfully, i.e., whether it can "step down" the high-voltage DC power into a stable low-voltage DC power supply to the low-pressure battery and all low-voltage electrical components in the vehicle, thus providing the necessary power for the low-pressure power steering pump motor controller to function properly.

[0034] Step S4: If yes, start the low-pressure power steering pump motor controller; if no, issue a prompt message indicating a DC-DC converter malfunction.

[0035] Specifically, if the DC-DC converter starts successfully, it indicates that it is fault-free. It can "step down" the high-voltage DC power into a stable low-voltage DC power, supplying power to the low-voltage battery and all low-voltage electrical components in the vehicle. The low-voltage battery then supplies power to the low-voltage power steering pump motor controller, enabling it to operate normally. Thus, when the DC-DC converter starts successfully, the low-voltage power steering pump motor controller is activated, driving the power steering pump motor to provide power steering and ensure vehicle safety. If the DC-DC converter fails to start, a fault message is issued to promptly notify relevant personnel for handling. This achieves dual-drive of the power steering pump motor, and the fault message facilitates early detection of driving hazards, enhancing safety and reliability.

[0036] Step S5: When the low-pressure oil pump motor controller starts successfully, control the vehicle to drive at an unlimited speed. During the operation of the oil pump motor driven by the low-pressure steering oil pump motor controller, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, save energy by controlling the operating state of the low-pressure steering oil pump motor controller.

[0037] Specifically: Once the low-pressure power steering pump motor controller is successfully activated, the low-pressure power steering system is engaged. At this time, the vehicle has no speed limit, meaning it can travel at the driver's desired speed. Simultaneously, the low-pressure power steering pump motor controller drives the pump motor to provide steering assistance, facilitating steering. Further, during this driving process, it is determined whether the vehicle meets the conditions for activating the power steering pump motor's energy-saving mode. For example, if the gear shift lever is in neutral (N), the actual gearbox position is neutral (N), the handbrake is engaged, all wheel speed signals are 0 km / h, and this state persists for more than a set threshold, then the vehicle meets the conditions for activating the power steering pump motor's energy-saving mode. This indicates the vehicle is stationary and has no steering requirement. Therefore, the low-pressure power steering pump motor controller is controlled to stop driving the pump motor, thus entering power-saving mode. This solves the driving safety problem caused by the lack of power steering. At the same time, by judging the vehicle's status, when it is determined that the vehicle has no steering demand based on whether the oil pump motor energy-saving mode is activated, the low-pressure steering oil pump motor controller is controlled to stop working. Thus, it can adaptively cut off the power to the low-pressure steering oil pump motor controller according to the actual working conditions, thereby achieving the effect of energy saving.

[0038] Therefore, the aforementioned control method for the vehicle's power steering system, by employing a dual-energy drive electro-hydraulic power steering pump motor control scheme, activates the low-pressure power steering pump motor controller when the high-pressure power steering pump motor controller malfunctions. This solves the safety issues caused by a single high-pressure drive electro-hydraulic power steering system failure. Because the dual-energy drive electro-hydraulic power steering pump motor control includes both a high-pressure and a low-pressure power steering pump motor controller with safety redundancy, vehicles using this method exhibit high control reliability and good safety. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode, shutting down the corresponding pump motor controller to conserve energy. Thus, while ensuring safe driving with power steering, the system also considers energy efficiency.

[0039] As a specific example, such as Figure 2 The diagram illustrates a communication network architecture for a power steering system according to an embodiment of the present invention. Figure 2 As shown, this power steering system is a dual-energy driven electro-hydraulic power steering control system, which includes an IC (Instrument Controller), a VCU (Vehicle Control Unit), HV_ODCAC (High Voltage Oil Delivery Control Actuator Controller), LV_ODCAC (Low Voltage Oil Delivery Control Actuator Controller), a DC-DC converter, and a battery management system for the low-voltage battery. The instrument cluster is connected to the vehicle controller via a data communication link, as are the high-voltage and low-voltage power steering pump controllers, the DC-DC converter, and the battery management system. Understandably, the instrument cluster can provide audible and visual alarms and display fault information in text. The vehicle controller monitors vehicle data in real time, and takes appropriate measures when an anomaly occurs.

[0040] In one embodiment of the present invention, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the high-pressure steering oil pump motor controller, including: controlling the high-pressure steering oil pump motor controller to stop driving the oil pump motor to save energy consumption.

[0041] Specifically, such as Figure 2As shown, the vehicle controller monitors the vehicle's data in real time. When the following conditions are met: the vehicle's gear shift lever is in N, the actual gear of the transmission is in N, the handbrake is engaged, all wheel speed signals are 0 km / h, and the duration of the above conditions exceeds a set threshold, the vehicle meets the conditions for starting the oil pump motor energy-saving mode. At this time, the high-pressure steering oil pump motor controller is controlled to stop driving the oil pump motor, thereby saving energy consumption.

[0042] As a specific implementation, the vehicle first performs a low-voltage power-on test, which checks the instrument panel, vehicle controller, high-voltage power steering pump controller, low-voltage power steering pump controller, DC-DC converter, and battery management system. If both the high-voltage and low-voltage power steering pump controllers are fault-free and the vehicle successfully gains high voltage, the vehicle starts the DC-DC converter and the high-voltage power steering pump controller. Once the high-voltage power steering pump controller starts successfully, the vehicle's speed is not limited. During driving, if the vehicle's gear shift lever is in neutral (N), the actual gear position of the transmission is in neutral (N), the handbrake is engaged, all wheel speed signals are 0 km / h, and this state lasts for more than a set threshold, then the vehicle meets the low-power mode conditions. At this time, the high-voltage power steering pump motor controller stops driving the power steering pump motor, thereby saving energy.

[0043] In one embodiment of the present invention, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the low-pressure steering oil pump motor controller, including: The low-pressure steering pump motor controller stops driving the pump motor to save energy.

[0044] Specifically, such as Figure 2 As shown, the vehicle controller (VCU) monitors vehicle data in real time. When the following conditions are met: the vehicle shift lever is in N, the actual gear position of the transmission is N, the handbrake is engaged, all wheel speed signals are 0 km / h, and the duration of the above conditions exceeds a set threshold, the vehicle meets the conditions for starting the oil pump motor energy-saving mode. At this time, the low-pressure steering oil pump motor controller stops driving the oil pump motor, thereby saving energy.

[0045] In a specific implementation, the vehicle first performs a low-voltage power-on test, which checks the instrument cluster, vehicle controller, high-voltage power steering pump controller, low-voltage power steering pump controller, DC-DC converter, and low-voltage battery management system. If the high-voltage power steering pump controller fails to start, the instrument cluster will issue an audible and visual alarm and a text message stating "High-voltage power steering system malfunction, please repair as soon as possible." Then, it checks if the DC-DC converter has started successfully. If it does, the low-voltage power steering pump controller is activated, and the instrument cluster IC displays a message stating "Please control your speed and maintain driving safety." If the low-voltage power steering pump controller starts successfully, the vehicle's speed is unlimited. During driving, if the vehicle's gear shift lever is in neutral (N), the actual gear position is neutral (N), the handbrake is engaged, all wheel speed signals are 0 km / h, and this state lasts for more than a set threshold, the vehicle meets the low-power mode conditions. In this case, the low-voltage power steering pump motor controller stops driving the pump motor, thereby saving energy.

[0046] In one embodiment of the present invention, the control method for the vehicle's power steering system further includes: when it is determined that the low-pressure power steering pump motor controller fails to start, controlling the vehicle's maximum speed to be limited to a preset safe speed.

[0047] Specifically, for the dual-energy drive electro-hydraulic power steering control system, combined with Figure 3 As shown, the high-voltage power battery can directly power the high-voltage power steering pump controller, which in turn controls the power steering pump motor. The high-voltage battery pack can also charge the low-voltage battery via a DC-DC converter, which in turn powers the low-voltage power steering pump controller, which in turn controls the power steering pump motor. Therefore, if the high-voltage power steering pump controller fails to activate, the power steering system only has the low-voltage power steering pump controller. If the low-voltage power steering pump controller also fails to activate, the steering wheel will become abnormally heavy, posing a safety hazard. Therefore, the vehicle's maximum speed must be limited to a preset "safe speed," meaning the speed should not be too high to ensure driving safety.

[0048] In one embodiment of the present invention, the conditions for activating the oil pump motor energy-saving mode include: the duration for which the vehicle remains in a preset state exceeds a preset time threshold. The preset state includes: the vehicle gear is in a first preset gear, the transmission gear is in a second preset gear, the parking function is activated, and the wheel speed signals of all wheels are preset values.

[0049] Specifically, when the vehicle is in normal driving condition, whether the high-pressure or low-pressure power steering pump controller controls the power steering pump, the VCU collects vehicle data to determine the vehicle status. If the vehicle status is in a preset state and the duration exceeds a preset time threshold, the vehicle is deemed to meet the conditions for activating the power steering pump motor energy-saving mode. The vehicle is then controlled to enter this mode, in which the corresponding power steering pump motor controller is powered off and stops working, thereby saving energy. In a specific embodiment, the preset state includes: the vehicle gear is in the first preset gear, such as neutral (N), the transmission gear is in the second preset gear, such as neutral (N), the vehicle's parking function is engaged (handbrake pulled), all wheel speed signals are at preset values, such as 0 km / h, and the duration of the above state exceeds a set threshold, such as, but not limited to, 5 minutes. Therefore, when all the above conditions are met, the vehicle is considered to be stationary and has no steering requirement. Therefore, no power steering is needed, and the corresponding power steering pump motor controller is powered off and stops working, thereby saving energy.

[0050] In one embodiment of the present invention, when the DC-DC converter fails to start, the method further includes: when it is determined that the vehicle has a driving demand, starting the low-pressure power steering pump motor controller; if the low-pressure power steering pump motor controller fails to start, controlling the maximum speed of the vehicle to be limited to no more than a preset safe speed, and issuing a prompt message to indicate a low-pressure power steering failure; if the low-pressure power steering pump motor controller starts successfully, identifying the type of the vehicle's low-pressure battery; and controlling the operating state of the vehicle according to the type of the low-pressure battery.

[0051] Specifically, when there is a need for driving, i.e., the vehicle manual specifies a need for power steering, and when both the high-pressure power steering pump controller and the DC-DC converter fail to start, combined with... Figure 3 As shown, the only way to drive the power steering pump motor is through the low-voltage power steering pump controller. Furthermore, because the DC-DC converter fails to start, it cannot supply power to the low-voltage battery. In other words, the low-voltage battery has no range and only its currently stored energy. Therefore, the low-voltage battery can only supply power to the low-voltage power steering pump controller using its own stored energy. Due to limited power and lack of stable range, the reliability and stability of the power supply are not high. Therefore, in this embodiment of the invention, the power supply process is further refined by identifying the type of low-voltage battery and selecting a power supply strategy based on the battery type. This allows for precise and effective allocation and control of the power according to the battery type, thereby improving the reliability of the low-voltage battery supplying power to the low-voltage power steering pump controller when there is no range, thus enhancing vehicle safety in this situation.

[0052] Specifically, when the low-voltage power steering pump controller starts successfully, the low-voltage battery supplies power to the controller based on its own existing electrical energy. At this time, the type of low-voltage battery is identified. This example provides two types of batteries: lithium batteries and non-lithium batteries, such as lead-acid batteries. After identifying the type of the vehicle's low-voltage battery, the vehicle's operating status is controlled according to the type of low-voltage battery to ensure reasonable power distribution, improve power supply reliability, and enhance driving safety.

[0053] In one embodiment of the present invention, controlling the operating state of the vehicle according to the type of the low-voltage battery includes: when it is determined that the low-voltage battery is a lithium battery, obtaining the current SOC (State of Charge) of the low-voltage battery. (Charge, State of Charge); If the current SOC is greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, the vehicle is controlled to drive without speed limit, and a warning message indicating low-voltage drive steering and caution to driving safety is issued; If the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, but the current SOC is greater than or equal to the third preset SOC threshold and less than or equal to the second preset SOC threshold, the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset SOC threshold is greater than the second preset SOC threshold, and the second preset SOC threshold is greater than the third preset SOC threshold; If the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, and the current SOC is not greater than or equal to the third preset SOC threshold and less than or equal to the second preset SOC threshold, the vehicle is controlled to prohibit power output, so that the vehicle speed is reduced and kept at zero, and the battery management system is allowed to perform charge latching.

[0054] Alternatively, in another embodiment of the present invention, when it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; if the current voltage is greater than or equal to a second preset voltage threshold and less than or equal to a first preset voltage threshold, the vehicle is controlled to drive without speed limit, and a warning message for indicating low-voltage drive steering and paying attention to driving safety is issued; if the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, but the current voltage is greater than or equal to a third preset voltage threshold and less than or equal to the second preset voltage threshold, the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset voltage threshold is greater than the second preset voltage threshold, and the second preset voltage threshold is greater than the third preset voltage threshold; if the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, and not greater than or equal to the third preset voltage threshold and less than or equal to the second preset voltage threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

[0055] Specifically, the type of low-voltage battery is first determined. If the low-voltage battery is a lithium battery, the vehicle's operating status is controlled based on its State of Charge (SOC). Three different SOC thresholds are set to divide the vehicle into three different SOC intervals, which then characterize the remaining charge of the low-voltage battery. In a specific embodiment, corresponding values ​​are assigned to each SOC threshold. For example, the current SOC is set as SOC threshold 1 (i.e., the first preset SOC threshold), a*current SOC is set as SOC threshold 2 (i.e., the second preset SOC threshold), and b*current SOC is set as SOC threshold 3 (i.e., the third preset SOC threshold). In this example, the order is 1 > a > b > 0, where a and b can be calibrated according to actual needs. Next, it is determined whether the current SOC threshold 1 ≥ current SOC ≥ SOC threshold 2. If so, it indicates that the low-voltage battery currently has sufficient remaining charge at a high level, which can provide a stable and reliable power supply to the low-voltage power steering pump controller, enabling the controller to provide stable steering assistance. The vehicle meets the conditions for safe driving, therefore the vehicle speed is not limited, and the instrument panel displays "Please control your speed to ensure driving safety." If not, i.e., the current SOC threshold 1 ≥ current SOC ≥ SOC threshold 2, then it is determined whether the current SOC threshold 2 ≥ current SOC ≥ SOC threshold 3. If so, it indicates that the low-voltage battery currently has insufficient remaining charge at a moderate level, which cannot provide a stable and reliable power supply to the low-voltage power steering pump controller, leading to... If the low-voltage power steering pump controller cannot guarantee stable power steering, the vehicle's maximum speed is limited to a preset "safe speed." If not, i.e., the current SOC threshold 1 is not greater than or equal to SOC threshold 2, and also not greater than or equal to SOC threshold 2, it indicates that the low-voltage battery's remaining charge is severely insufficient and at a low level, unable to supply power to the low-voltage power steering pump controller. This causes the controller to malfunction, meaning it cannot provide power steering. Driving in this condition poses a serious safety hazard. Therefore, power output is prohibited, the vehicle speed is reduced to 0 km / h, and the battery management system is allowed to lock the battery charge to ensure the safety of the vehicle and its occupants. Simultaneously, this ensures that the low-voltage battery does not become severely depleted or run out of power, thus protecting the low-voltage battery's charge level.

[0056] On the other hand, if the low-voltage battery is not a lithium battery, but rather a lead-acid battery, the vehicle's operating state is controlled based on its voltage state. Three different voltage thresholds are set to divide the vehicle into three different voltage ranges, which in turn characterize the remaining charge of the low-voltage battery. In a specific embodiment, each voltage threshold is assigned a corresponding value. For example, U1 is set as voltage threshold 1 (i.e., the first preset voltage threshold), U2 is set as voltage threshold 2 (i.e., the second preset voltage threshold), and U3 is set as voltage threshold 3 (i.e., the third preset voltage threshold). In this example, the order is U1 > U2 > U3 > minimum operating voltage of the battery. U1, U2, and U3 can all be calibrated according to actual needs. Next, it is determined whether the current voltage threshold 1 ≥ current voltage ≥ voltage threshold 2. If so, it indicates that the low-voltage battery currently has sufficient remaining charge at a high level, providing a stable and reliable power supply to the low-voltage power steering pump controller. This allows the controller to provide stable power steering, meeting the conditions for safe driving. Therefore, the vehicle is not subject to speed limits, and the instrument panel displays the message "Please control your speed to ensure driving safety." If not, meaning the current voltage threshold 1 ≥ current voltage ≥ voltage threshold 2, then it is determined whether the current voltage threshold 2 ≥ current voltage ≥ voltage threshold 3. If so, it indicates that the current low-voltage battery is not sufficiently charged, at a moderate level, and cannot provide power to the low-voltage power steering pump controller. Providing a stable, reliable, and sufficient power supply to the low-pressure power steering pump controller prevents it from guaranteeing stable power steering. Consequently, the vehicle's maximum speed is limited to the preset "safe speed." If, however, the current voltage threshold is not 1 ≥ current voltage ≥ voltage threshold 2, and also not 2 ≥ current voltage ≥ voltage threshold 3, it indicates that the low-pressure battery's remaining charge is severely insufficient and at a low level. This prevents it from supplying power to the low-pressure power steering pump controller, causing it to malfunction and fail to provide power steering. This poses a serious safety hazard, so power output is prohibited, and the vehicle speed is reduced to 0 km / h to ensure the safety of the vehicle and its occupants.

[0057] In one embodiment of the present invention, after the low-pressure power steering pump motor controller fails to start, the maximum speed of the vehicle is limited to a preset safe speed, and a prompt message indicating a low-pressure power steering failure is issued, the method further includes: when it is determined that the low-pressure battery is a lithium battery, obtaining the current SOC of the low-pressure battery; if the current SOC is less than or equal to a third preset SOC threshold, controlling the vehicle to prohibit power output so that the vehicle speed is reduced and kept at zero, and allowing the battery management system to perform charge latching.

[0058] Alternatively, in another embodiment of the present invention, when it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; if the current voltage is less than or equal to a third preset voltage threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

[0059] Specifically, when the low-pressure power steering pump controller fails to start, the vehicle's maximum speed is limited to a set safe speed, and a fault message for low-pressure power steering is issued through the instrument panel. When the battery is detected to be a lithium battery, the vehicle controller will obtain the current SOC of the low-pressure battery. If the judgment condition is met and the current SOC is less than or equal to the third preset SOC threshold, it indicates that the current lithium battery power is seriously insufficient and cannot provide power steering, which poses a safety hazard. Therefore, the vehicle is controlled to prohibit power output, so that the vehicle speed is reduced and kept at zero, and the battery management system is allowed to perform power lock-in to ensure the safety of the vehicle and personnel. At the same time, it ensures that the low-pressure battery is not severely depleted or completely depleted, thus achieving power protection for the low-pressure battery. On the other hand, if it is detected that the battery is not a lithium battery, but a lead-acid battery, the current voltage of the low-voltage battery is obtained. If the current voltage is less than or equal to a third preset voltage threshold, it indicates that the current low-voltage battery has a serious lack of power and cannot provide steering assistance, which will pose a safety hazard to driving. Therefore, the vehicle is controlled to prohibit power output, so that the vehicle speed is reduced and kept at zero, thereby ensuring the safety of the vehicle and personnel.

[0060] In one embodiment of the present invention, the control method of the vehicle's power steering system further includes: in response to the failure of the high-voltage power-on, not starting the high-voltage power steering pump motor controller and the low-voltage power steering pump motor controller, and controlling the vehicle to prohibit power output.

[0061] Alternatively, in one embodiment of the present invention, before the vehicle is powered on at high voltage, the method further includes: in response to the successful power-on of the vehicle at low voltage, controlling the high-voltage power steering pump motor controller and the low-voltage power steering pump motor controller to perform a low-voltage self-test; if the low-voltage self-test result determines that the high-voltage power steering pump motor controller and / or the low-voltage power steering pump motor controller have a fault that prevents them from working, then issuing a corresponding prompt message to indicate a high-voltage power steering fault and / or a low-voltage power steering fault.

[0062] Specifically, after the vehicle successfully powers on at low voltage, it will perform low-voltage self-tests on the instrument panel, vehicle controller, high-voltage power steering pump controller, low-voltage power steering pump controller, DC-DC converter, and battery management system. Based on the results of the low-voltage self-test, if a fault that prevents operation is detected, the vehicle controller will issue a fault message through the instrument panel if the high-voltage power steering pump motor controller is faulty, and if the low-voltage power steering pump motor controller is faulty, the vehicle controller will issue a fault message through the instrument panel if both the high-voltage and low-voltage power steering pump motor controllers are faulty.

[0063] The vehicle power steering system control method according to an embodiment of the present invention employs a dual-energy drive electro-hydraulic power steering pump motor control scheme. When the high-pressure power steering pump motor controller malfunctions, the low-pressure power steering pump motor controller is activated. This solves the safety problem caused by a single high-pressure drive electro-hydraulic power steering system failure. Because the dual-energy drive electro-hydraulic power steering pump motor control includes both a high-pressure and a low-pressure power steering pump motor controller with safety redundancy, the vehicle exhibits high control reliability and good safety during power steering control. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode, shutting down the corresponding pump motor controller to save energy. Thus, while ensuring safe driving with power steering, the energy efficiency of the power steering system is also considered.

[0064] Further embodiments of the present invention also disclose a vehicle steering assist system.

[0065] Figure 4 This is a schematic diagram of the structure of a vehicle's power steering system according to an embodiment of the present invention, as shown below. Figure 4 As shown, the vehicle's power steering system 100 includes: a high-pressure power steering pump motor controller 110, a DC-DC converter 120, a low-pressure power steering pump motor controller 130, a control module 140, and a power steering pump motor (not shown in the figure).

[0066] Specifically, the oil pump motor is used for power steering.

[0067] The high-pressure steering oil pump motor controller 110 is used to drive the oil pump motor.

[0068] The low-pressure steering oil pump motor controller 130 is used to drive the oil pump motor.

[0069] The control module 140 is used to start the high-voltage power steering pump motor controller 110 and the vehicle's DC-DC converter 120 in response to a successful high-voltage power-on of the vehicle; when the high-voltage power steering pump motor controller 110 starts successfully, it controls the vehicle to drive at an unlimited speed, and during the operation of the pump motor driven by the high-voltage power steering pump motor controller 110, when the vehicle meets the conditions for starting the pump motor energy-saving mode, it saves energy by controlling the operating state of the high-voltage power steering pump motor controller 110; when the high-voltage power steering pump motor controller 110 fails to start, it determines that... If the DC-DC converter 120 is successfully started, a prompt message indicating a high-pressure power steering malfunction is issued. If yes, the low-pressure power steering pump motor controller 130 is started; otherwise, a prompt message indicating a DC-DC converter 120 malfunction is issued. When the low-pressure power steering pump motor controller is successfully started, the vehicle is controlled to travel at an unlimited speed. During the operation of the power steering pump motor driven by the low-pressure power steering pump motor controller 130, when the vehicle meets the conditions for activating the power steering pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the low-pressure power steering pump motor controller 130.

[0070] In one embodiment of the present invention, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, the control module 140 saves energy by controlling the operating state of the high-pressure steering oil pump motor controller 110, including controlling the high-pressure steering oil pump motor controller 110 to stop driving the oil pump motor to save energy.

[0071] In one embodiment of the present invention, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, the control module 140 saves energy by controlling the operating state of the low-pressure steering oil pump motor controller 130, including: controlling the low-pressure steering oil pump motor controller 130 to stop driving the oil pump motor to save energy.

[0072] In one embodiment of the present invention, when it is determined that the low-pressure power steering pump motor controller 130 fails to start, the control module 140 is further configured to: control the maximum speed of the vehicle to be limited to a preset safe speed.

[0073] In one embodiment of the present invention, the conditions for activating the oil pump motor energy-saving mode include: the duration for which the vehicle remains in a preset state exceeds a preset time threshold, the preset state including: the vehicle is in a first preset gear, the transmission is in a second preset gear, the parking function is activated, and the wheel speed signals of all wheels are preset values.

[0074] In one embodiment of the present invention, when the DC-DC converter 120 fails to start, the control module 140 is further configured to: When it is determined that the vehicle needs to travel, the low-pressure power steering pump motor controller 130 is activated; if the low-pressure power steering pump motor controller 130 fails to start, the maximum speed of the vehicle is controlled to be limited to a preset safe speed, and a prompt message indicating a low-pressure power steering fault is issued; if the low-pressure power steering pump motor controller 130 starts successfully, the type of the vehicle's low-pressure battery is identified; and the operating status of the vehicle is controlled according to the type of the low-pressure battery.

[0075] In one embodiment of the present invention, the control module 140 controls the operating state of the vehicle according to the type of the low-voltage battery, including: when the low-voltage battery is determined to be a lithium battery, obtaining the current SOC of the low-voltage battery; if the current SOC is greater than or equal to a second preset SOC threshold and less than or equal to a first preset SOC threshold, controlling the vehicle to drive without speed limit and issuing a warning message to indicate low-voltage drive steering and pay attention to driving safety; if the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, but the current SOC is greater than or equal to a third preset SOC threshold... If the current SOC is greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, then the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset SOC threshold is greater than the second preset SOC threshold, and the second preset SOC threshold is greater than the third preset SOC threshold; if the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, and the current SOC is not greater than or equal to the third preset SOC threshold and less than or equal to the second preset SOC threshold, then the vehicle is controlled to prohibit power output, so that the vehicle speed is reduced and kept at zero, and the battery management system is allowed to perform charge latch-up.

[0076] Alternatively, in another embodiment of the present invention, when it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; If the current voltage is greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, the vehicle is controlled to drive without speed limit, and a warning message indicating low-voltage drive steering and cautioning driving safety is issued. If the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, but is greater than or equal to the third preset voltage threshold and less than or equal to the second preset voltage threshold, the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset voltage threshold is greater than the second preset voltage threshold, and the second preset voltage threshold is greater than the third preset voltage threshold. If the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, and is not greater than or equal to the third preset voltage threshold and less than or equal to the second preset voltage threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

[0077] In one embodiment of the present invention, after the control module 140 fails to start the low-pressure power steering pump motor controller 130, controls the maximum speed of the vehicle to be limited to a preset safe speed, and issues a prompt message indicating a low-pressure power steering malfunction, it is further configured to: When the low-voltage battery is determined to be a lithium battery, the current SOC of the low-voltage battery is obtained; if the current SOC is less than or equal to a third preset SOC threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero, and the battery management system is allowed to perform power latching.

[0078] Alternatively, in another embodiment of the present invention, when it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; if the current voltage is less than or equal to a third preset voltage threshold, the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

[0079] In one embodiment of the present invention, the control module 140 is further configured to: in response to the failure of the high-voltage power-on, not start the high-voltage power steering pump motor controller 110 and the low-voltage power steering pump motor controller 130, and control the vehicle to prohibit power output; or, Before the vehicle is powered on at high voltage, the control module 140 is further configured to: in response to the successful low-voltage power-on of the vehicle, control the high-voltage power steering pump motor controller 110 and the low-voltage power steering pump motor controller 130 to perform a low-voltage self-test; if the low-voltage self-test result determines that the high-voltage power steering pump motor controller 110 and / or the low-voltage power steering pump motor controller 130 have a fault that prevents them from working, then issue a corresponding prompt message indicating a high-voltage power steering fault and / or a low-voltage power steering fault.

[0080] It should be noted that when providing steering assistance to the vehicle, the specific implementation of the vehicle steering assistance system 100 is similar to the specific implementation of the control method of the vehicle steering assistance system in any of the above embodiments of the present invention. Therefore, for a detailed exemplary description of the vehicle steering assistance system 100, please refer to the relevant description of the control method of the vehicle steering assistance system mentioned above. To reduce redundancy, it will not be repeated here.

[0081] Therefore, the power steering system 100 of the vehicle according to the present invention, by adopting a dual-energy drive electro-hydraulic power steering pump motor control scheme, activates the low-pressure power steering pump motor controller 130 when the high-pressure power steering pump motor controller 110 fails to operate normally. This solves the safety problem caused by the failure of the single high-pressure drive electro-hydraulic power steering system 100. Since the dual-energy drive electro-hydraulic power steering pump motor control includes both the high-pressure power steering pump motor controller 110 and the low-pressure power steering pump motor controller 130, with safety redundancy, the vehicle exhibits high control reliability and good safety during power steering control. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode and shuts down the corresponding pump motor controller to save energy. Thus, while ensuring safe driving with power steering, the energy efficiency of the power steering system 100 is also considered.

[0082] Further embodiments of the present invention disclose a computer-readable storage medium storing a control program for a vehicle's power steering system. When executed by a processor, the control program implements the control method for the vehicle's power steering system as described in any of the above embodiments of the present invention. For a detailed description of the execution process of the control method for the vehicle's power steering system, please refer to the relevant sections above, which will not be repeated here.

[0083] Therefore, according to the computer-readable storage medium of the present invention, when the control program of the vehicle's power steering system stored thereon is executed by a processor, a dual-energy drive electro-hydraulic power steering pump motor control scheme is adopted. When the high-pressure power steering pump motor controller fails to operate normally, the low-pressure power steering pump motor controller is activated, solving the safety problem caused by the failure of a single high-pressure drive electro-hydraulic power steering system. Since the dual-energy drive electro-hydraulic power steering pump motor control includes both a high-pressure and a low-pressure power steering pump motor controller, with safety redundancy, the vehicle exhibits high control reliability and good safety during power steering control. Furthermore, during dual-energy drive power steering, when the energy-saving mode conditions are met, the system enters energy-saving mode and shuts down the corresponding pump motor controller to save energy. Thus, while ensuring safe driving with power steering, the energy efficiency of the power steering system is also considered. In the description of this specification, references to terms such as "an embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the terms used above do not necessarily refer to the same embodiments or examples.

[0084] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A control method for a vehicle's power steering system, characterized in that, The power steering system includes a hydraulic pump motor for power steering and a high-pressure power steering pump motor controller and a low-pressure power steering pump motor controller for driving the hydraulic pump motor. The method includes: In response to the successful high-voltage power-on of the vehicle, the high-voltage power steering pump motor controller and the vehicle's DC-DC converter are activated; When the high-pressure power steering pump motor controller is successfully started, the vehicle is controlled to drive at an unlimited speed. During the operation of the power steering pump motor driven by the high-pressure power steering pump motor controller, when the vehicle meets the conditions for starting the power steering pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the high-pressure power steering pump motor controller. When the high-pressure power steering pump motor controller fails to start, determine whether the DC-DC converter has started successfully and issue a prompt message indicating a high-pressure power steering failure. If yes, then start the low-pressure power steering pump motor controller; if no, then issue a prompt message indicating a fault in the DC-DC converter. When the low-pressure oil pump motor controller starts successfully, the vehicle is controlled to drive at an unlimited speed. During the operation of the oil pump motor driven by the low-pressure steering oil pump motor controller, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the low-pressure steering oil pump motor controller.

2. The control method for the vehicle's power steering system according to claim 1, characterized in that, When the vehicle meets the conditions for activating the energy-saving mode of the power steering pump motor, energy consumption is saved by controlling the operating state of the high-pressure power steering pump motor controller, including: The high-pressure steering pump motor controller is controlled to stop driving the pump motor to save energy.

3. The control method for the vehicle's power steering system according to claim 1, characterized in that, When the vehicle meets the conditions for activating the energy-saving mode of the power steering pump motor, energy consumption is saved by controlling the operating state of the low-pressure power steering pump motor controller, including: The low-pressure steering pump motor controller is controlled to stop driving the pump motor in order to save energy.

4. The control method for the vehicle's power steering system according to claim 1, characterized in that, Also includes: When it is determined that the low-pressure power steering pump motor controller fails to start, the maximum speed of the vehicle is controlled to be limited to a preset safe speed.

5. The control method for the power steering system of a vehicle according to any one of claims 1-4, characterized in that, The conditions for starting the oil pump motor energy-saving mode include: the duration for which the vehicle remains in a preset state exceeds a preset time threshold. The preset state includes: the vehicle is in a first preset gear, the transmission is in a second preset gear, the parking function is activated, and the wheel speed signals of all wheels are preset values.

6. The control method for the vehicle's power steering system according to claim 1, characterized in that, When the DC-DC converter fails to start, the following is also included: When it is determined that the vehicle needs to drive, the low-pressure power steering pump motor controller is activated. If the low-pressure power steering pump motor controller fails to start, the maximum speed of the vehicle will be limited to a preset safe speed, and a prompt message indicating a low-pressure power steering failure will be issued. If the low-pressure power steering pump motor controller starts successfully, the type of the vehicle's low-pressure battery is identified. The operating status of the vehicle is controlled according to the type of the low-voltage battery.

7. The control method for the vehicle's power steering system according to claim 6, characterized in that, The control of the vehicle's operating status based on the type of the low-voltage battery includes: When the low-voltage battery is determined to be a lithium battery, the current SOC of the low-voltage battery is obtained; If the current SOC is greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, then the vehicle is controlled to drive without speed limit and a warning message is issued to indicate low-pressure drive steering and pay attention to driving safety. If the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, but the current SOC is greater than or equal to the third preset SOC threshold and less than or equal to the second preset SOC threshold, then the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset SOC threshold is greater than the second preset SOC threshold, and the second preset SOC threshold is greater than the third preset SOC threshold. If the current SOC is not greater than or equal to the second preset SOC threshold and less than or equal to the first preset SOC threshold, and the current SOC is not greater than or equal to the third preset SOC threshold and less than or equal to the second preset SOC threshold, then the vehicle is controlled to prohibit power output, so that the vehicle speed is reduced and maintained at zero, and the battery management system is allowed to perform charge latch-up; or, When it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; If the current voltage is greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, then the vehicle is controlled to drive at an unlimited speed, and a warning message is issued to indicate low-voltage drive steering and to pay attention to driving safety. If the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, but the current voltage is greater than or equal to the third preset voltage threshold and less than or equal to the second preset voltage threshold, then the maximum speed of the vehicle is controlled to be limited to a preset safe speed, wherein the first preset voltage threshold is greater than the second preset voltage threshold, and the second preset voltage threshold is greater than the third preset voltage threshold. If the current voltage is not greater than or equal to the second preset voltage threshold and less than or equal to the first preset voltage threshold, and the current voltage is not greater than or equal to the third preset voltage threshold and less than or equal to the second preset voltage threshold, then the vehicle is controlled to prohibit power output so that the vehicle speed is reduced and kept at zero.

8. The control method for the vehicle's power steering system according to claim 6, characterized in that, After the low-pressure power steering pump motor controller fails to start, limits the vehicle's maximum speed to a preset safe speed, and issues a warning message indicating a low-pressure power steering malfunction, the system further includes: When the low-voltage battery is determined to be a lithium battery, the current SOC of the low-voltage battery is obtained; If the current SOC is less than or equal to a third preset SOC threshold, then the vehicle is controlled to disable power output, so that the vehicle speed is reduced and maintained at zero, and the battery management system is allowed to perform charge latch-up; or, When it is determined that the low-voltage battery is not a lithium battery, the current voltage of the low-voltage battery is obtained; If the current voltage is less than or equal to a third preset voltage threshold, the vehicle is controlled to disable power output so that the vehicle speed is reduced and kept at zero.

9. The control method for the power steering system of a vehicle according to claim 1, characterized in that, Also includes: In response to the failure of high-voltage power-on, the high-voltage power steering pump motor controller and the low-voltage power steering pump motor controller are not started, and the vehicle is controlled to prohibit power output. or, Before the vehicle is powered on at high voltage, the following is also included: In response to the successful low-voltage power-on of the vehicle, the high-voltage power steering pump motor controller and the low-voltage power steering pump motor controller are controlled to perform a low-voltage self-test; If the low-pressure self-test results indicate that the high-pressure power steering pump motor controller and / or the low-pressure power steering pump motor controller are faulty and prohibited from operating, a corresponding prompt message will be issued to indicate the high-pressure power steering fault and / or the low-pressure power steering fault.

10. A power steering system for a vehicle, characterized in that, include: Oil pump motor for power steering; High-pressure steering oil pump motor controller for driving the oil pump motor; Low-pressure steering oil pump motor controller for driving the oil pump motor; The controller is configured to: In response to the successful high-voltage power-on of the vehicle, the high-voltage power steering pump motor controller and the vehicle's DC-DC converter are activated; When the high-pressure power steering pump motor controller is successfully started, the vehicle is controlled to drive at an unlimited speed. During the operation of the power steering pump motor driven by the high-pressure power steering pump motor controller, when the vehicle meets the conditions for starting the power steering pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the high-pressure power steering pump motor controller. When the high-pressure power steering pump motor controller fails to start, determine whether the DC-DC converter has started successfully and issue a prompt message indicating a high-pressure power steering failure. If yes, then start the low-pressure power steering pump motor controller; if no, then issue a prompt message indicating a fault in the DC-DC converter. When the low-pressure oil pump motor controller starts successfully, the vehicle is controlled to drive at an unlimited speed. During the operation of the oil pump motor driven by the low-pressure steering oil pump motor controller, when the vehicle meets the conditions for starting the oil pump motor energy-saving mode, energy consumption is saved by controlling the operating state of the low-pressure steering oil pump motor controller.

11. A vehicle, characterized in that, include: The vehicle steering assist system as described in claim 10; or, A processor, a memory, and a control program for a vehicle's power steering system stored in the memory and executable on the processor, wherein the control program for the vehicle's power steering system, when executed by the processor, implements the control method for the vehicle's power steering system as described in any one of claims 1-9.

Images