A dual-source oil pump control method and system

Abstract

The present invention discloses a dual-source oil pump control method and system, relating to the field of new energy vehicle technology. When the oil pump is operating normally, the system determines whether the vehicle's CAN bus is operating normally. When the CAN bus is operating normally, the system determines whether the high-voltage system is operating normally and determines whether a high-voltage power outage is required. When the CAN bus is abnormal, the system determines whether the low-voltage signal port receives a high level. When the high-voltage system is abnormal and the fault is irrecoverable, the vehicle speed is greater than a set value, or the low-voltage signal port receives a high level, the low-voltage is enabled. The present invention provides a hierarchical energy allocation optimization strategy. Through control strategy optimization, the system significantly reduces the time delay in switching between high- and low-pressure oil pumps and enhances steering safety.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and in particular to a dual-source oil pump control method and system. Background Art

[0002] New energy vehicles replace traditional engines with battery-powered motors. Accordingly, electric power steering (EPS) is incorporated into the steering systems of various electric vehicles. It is a key component of new energy vehicles, enhancing overall vehicle performance while also boosting their economic benefits in the market. Vehicle manufacturers currently employ a common method of steering the vehicle using a high- and low-pressure dual-source power steering oil pump. By incorporating a power steering emergency boost module into the integrated power supply, this module can provide a short-term operating voltage for the power steering oil pump in the event of a sudden drop in high voltage during normal driving at speeds greater than or equal to 5 km / h. However, adding an intelligent emergency module can increase material and cost costs. Damage to the DC / AC controller can cause the entire braking system to malfunction, hindering maintenance and potentially causing traffic accidents.

[0003] CN110758551A discloses a control method and control system for a dual-source oil pump of an automobile. The vehicle controller and the dual-source oil pump controller obtain the real-time allowable current value of the energy storage device in real time; compare the real-time allowable current value of the energy storage device with a preset current threshold, and control the switching of the enable states of the vehicle's high-voltage device and the dual-source oil pump controller through the vehicle controller, and control the switching of the enable states of the high-pressure oil pump and the low-pressure oil pump through the dual-source oil pump controller; the vehicle controller monitors the vehicle speed index and the oil pump operating time based on the enable states of the high-pressure oil pump and the low-pressure oil pump fed back by the dual-source oil pump controller, and turns off the output enable of the dual-source oil pump controller and the vehicle controller after the vehicle speed index and the oil pump operating time reach the stop condition.

[0004] For the above solution, since normal current of the energy storage device is a sufficient but not necessary condition for enabling the high voltage of the oil pump, the power battery not only provides power for the oil pump, but when other electrical appliances are not working, the battery current may be very low. However, at this time, enabling the high voltage of the oil pump does not affect the operation of the entire vehicle. This judgment method is not accurate. The high and low voltage enabling of the oil pump cannot be determined by judging the difference between the real-time allowable current value of the energy storage device and the preset current threshold. In addition, the power battery supplies energy to the entire vehicle electrical appliances, and the current threshold is difficult to determine. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a dual-source oil pump control method and system, providing a hierarchical energy distribution optimization strategy, and through control strategy optimization, greatly reducing the time delay of high and low pressure oil pump switching and enhancing steering safety.

[0006] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0007] In a first aspect, an embodiment of the present invention provides a dual-source oil pump control method. When the oil pump is operating normally, it is determined whether the vehicle CAN bus is normal; when the CAN is normal, it is determined whether the high-voltage system is normal and whether the high-voltage power supply needs to be cut off; when the CAN is abnormal, it is determined whether the low-voltage signal port receives a high level;

[0008] When the high voltage system is partially abnormal and the fault is unrecoverable, and the vehicle speed is greater than the set value, or when the low voltage signal port receives a high level, the low voltage is enabled.

[0009] As a further implementation, the control method specifically includes:

[0010] When the oil pump is working normally, the CAN bus communication is normal, and the high-voltage system of the vehicle is normal, the high-pressure oil pump will work normally; when the high-pressure system is abnormal and the high-voltage DC / AC controller reports a recoverable fault, the high-pressure side oil pump is not allowed to stop; when the high-pressure system is abnormal and the vehicle speed is greater than the set value, the low-voltage is enabled;

[0011] When the oil pump works normally, the CAN bus communication is abnormal and the vehicle speed is greater than the set value, the low-pressure oil pump starts when the low-voltage signal port receives a high level; when no high level is received, the high-pressure side oil pump continues to work.

[0012] As a further implementation method, in the low-voltage enabled state, when there is a partial abnormality in the high-voltage system and the vehicle speed is greater than the set value, and the low-voltage DC / AC controller detects that the oil pump motor speed is lower than the set speed threshold, the battery emergency assist is intervened.

[0013] As a further implementation method, in the low-voltage enabling state, when the oil pump motor speed is lower than the set speed threshold, the battery emergency assist is intervened.

[0014] As a further implementation method, after the low-pressure oil pump is started, if it continues to run for a set time, the low-voltage DC / AC controller will automatically shut down; if the oil pump control power supply at the low-voltage signal port is directly cut off and shut down, the low-voltage DC / AC controller will shut down; if the CAN bus of the vehicle controller and the low-voltage DC / AC controller is lost, the low-voltage hard-line enable at the low-voltage signal port will be powered off, and the low-voltage DC / AC controller will shut down.

[0015] As a further implementation method, when the vehicle is in the ON gear and the battery is not in the high-voltage state, the oil pump trigger button is pressed continuously for a set number of times, and the vehicle controller forces the low-voltage DC / AC controller to be enabled. The low-voltage DC / AC controller starts the low-voltage part after detecting that the motor speed is 0r / min and setting the time.

[0016] As a further implementation method, when the high-voltage system is partially abnormal and the vehicle speed is greater than the set value, the vehicle loses high voltage or the vehicle controller receives an unrecoverable fault signaled by the high-voltage DC / AC controller at the same time within the same message cycle, the low-voltage enable is enabled and the high-voltage DC / AC controller is disconnected.

[0017] On the second aspect, an embodiment of the present invention also provides a dual-source oil pump control system, including a vehicle controller, a high-voltage system part and a low-voltage system part. The vehicle controller is connected to the high-voltage DC / AC controller and the power battery through a CAN bus, and the control signal of the low-voltage DC / AC controller can be transmitted to the vehicle controller through the CAN bus to switch the working state of the oil pump.

[0018] As a further implementation, the high-voltage system includes a power battery, a high-voltage DC / AC controller, and a high-voltage motor. The high-voltage DC / AC controller is used to convert the direct current of the power battery into alternating current for use by the high-voltage motor.

[0019] The low-voltage system includes batteries, low-voltage DC / AC controllers and low-voltage motors. The low-voltage DC / AC controller is used to convert the direct current of the battery into alternating current for use by the low-voltage motor.

[0020] As a further implementation, the high-voltage motor and the low-voltage motor are coaxial dual-winding motors, which are integrated into a dual-source power steering oil pump.

[0021] The beneficial effects of the present invention are as follows:

[0022] (1) The present invention adopts a combination of CAN bus enable and hard line enable to perform precise control according to the working status of the whole vehicle. When the whole vehicle is working normally, the oil pump switches to low-voltage enable, and the whole vehicle loses the steering function and stops working. CAN control is prioritized, the control strategy is prioritized, and the emergency control effect is good, which solves the problems of complex wiring from the whole vehicle controller to multiple controllers, complex design of multiple wiring harnesses, and increased material costs.

[0023] (2) The present invention adopts a dual-source control method. When the vehicle suddenly encounters an irreversible fault or a high-voltage drop problem during normal driving, the low-voltage emergency energy part is started, and the steering system can be kept in an assisted state for three minutes, so that the driver has sufficient time to adjust the vehicle position. When the high-voltage part suddenly has a problem and cannot work, the whole vehicle is prevented from having no steering assistance and the danger occurs, thereby ensuring the life and property safety of the driver and passengers.

[0024] (3) When the whole vehicle is not under high voltage, the present invention adopts the low-voltage steering offline detection mode to detect whether the low-voltage controller end can work normally, which is convenient and quick, so that the driver has sufficient time to take control measures for the problem vehicle, avoid the occurrence of traffic accidents, and improve the safety and reliability of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0026] Figure 1 is a control flow chart according to one or more embodiments of the present invention;

[0027] Figure 2 is a schematic diagram of a control system according to one or more embodiments of the present invention. DETAILED DESCRIPTION

[0028] Example 1:

[0029] This embodiment provides a dual-source oil pump control method, which combines CAN bus enable and hard line enable, and adopts a CAN bus control priority control strategy. By prioritizing the control strategy, the emergency control effect is good. Figure 1 As shown, the specific control method is:

[0030] When the vehicle's running oil pump is working normally and the CAN bus communication is normal, if the high-voltage system of the whole vehicle is normal, the high-pressure oil pump will work normally; if the high-voltage system is abnormal and the high-voltage DC / AC controller reports a recoverable fault, the high-pressure side oil pump is not allowed to stop and the low-voltage DC / AC controller will not work; if the high-voltage system is abnormal and the vehicle speed is greater than 5KM / h, the vehicle loses high voltage or the vehicle controller receives an irrecoverable fault from the high-voltage DC / AC controller at the same time within the same message cycle, the vehicle controller VCU sends a low-voltage enable command and a command to disconnect the high-voltage DC / AC controller at the same time; when the vehicle speed is less than 5KM / h, the oil pump stops; among them, if the low-voltage DC / AC controller detects that the oil pump motor speed is lower than a certain speed threshold, the battery emergency assist is intervened.

[0031] When the vehicle's oil pump is operating normally, the CAN bus communication is abnormal, and the vehicle speed is greater than 5KM / h, the low-voltage DC / AC controller detects whether the low-voltage hard-line enable of the low-voltage signal port receives a high-level enable sent by the VCU. If a high level is received, the low-pressure oil pump starts; if not, the high-pressure side oil pump continues to work; among them, if the low-voltage DC / AC controller detects that the oil pump motor speed is lower than a certain speed threshold, the battery emergency assist is intervened.

[0032] Among them, after the low-pressure oil pump is started, if it continues to run for 3 minutes, the low-voltage DC / AC controller will automatically shut down; if the oil pump control power supply at the low-voltage signal port is directly cut off and shut down, the low-voltage DC / AC controller will shut down; when the CAN bus of the vehicle controller VCU and the low-voltage DC / AC controller is disconnected, the low-voltage hard-line enable at the low-voltage signal port is powered off, and the low-voltage DC / AC controller will shut down.

[0033] It should be noted that CAN bus communication is normal: there are no level 1, 2, 3 or 4 faults in the whole vehicle; CAN bus communication is abnormal: the whole vehicle has level 1, 2, 3 or 4 faults. When it is a level 4 fault (irrecoverable fault), the whole vehicle reduces high pressure and enables low pressure; otherwise, the oil pump continues to enable high pressure.

[0034] Vehicle fault level handling: Level 1 < Level 2 < Level 3 < Level 4; Level 1 fault: no handling; Level 2 fault: battery power is limited, the VCU reduces power control based on the battery power limit; Level 3 fault: battery power is severely limited, the VCU controls the vehicle to limp according to the battery power; Level 4 fault: the battery requests high voltage reduction, the VCU controls the vehicle to stop within 35 seconds and sends a high voltage reduction command.

[0035] The faults corresponding to each level are existing technologies. For example, current sensor failure, high data of the Hall sensor small ring, low data of the Hall sensor small ring, slave board balancing circuit failure, main positive contactor open circuit, pre-charge failure, etc. are level one faults; low single cell voltage, slightly high battery cell temperature, high pole temperature, slightly low insulation resistance, too high SOC, abnormal battery heating, etc. are level two faults; moderately high single cell voltage, moderately low single cell voltage, excessive branch cumulative voltage difference, seriously high pole temperature, moderately high battery discharge current, etc. are level three faults; seriously high single cell voltage, seriously low single cell voltage, seriously large single cell pressure difference, seriously high battery cell temperature, seriously low battery temperature, seriously low insulation resistance, etc. are level four faults.

[0036] This embodiment also provides an oil pump low-pressure steering offline detection mode. When the vehicle is in the ON gear and the battery is not in the high-voltage state, press the oil pump trigger button three times in succession. The vehicle controller sends a message to force the low-voltage DC / AC controller to enable. The low-voltage DC / AC controller detects that the motor speed is 0r / min and starts low voltage after 0.5 seconds. The working time is 25 seconds and the deceleration stop is 5 seconds.

[0037] This mode is used to test the proper functioning of the low-pressure system. It's quick, convenient, and highly reliable, allowing for timely control of problematic vehicles. This prevents the high-pressure steering pump from malfunctioning or malfunctioning when the low-pressure system fails, preventing the low-pressure pump from switching to the high-pressure pump. This could affect steering function and even cause accidents. After operating in offline testing mode, the high-pressure system must be re-activated and re-disabled to ensure proper activation.

[0038] In this embodiment, when an abnormality occurs in part of the high-voltage system circuit, the vehicle controller VCU and the low-voltage end interface will switch the low-pressure oil pump to work according to the specific situation. The emergency control effect is good, ensuring that the vehicle will not lose control instantly and cause a safety accident. At the same time, it solves the delay and steering wheel loss of control that occur during the high-low voltage switching process.

[0039] The low-voltage DC / AC controller of this embodiment is activated when the high-voltage motor speed exceeds a certain value for the first time; the control strategy is prioritized, which greatly reduces the time delay of switching between high-pressure and low-pressure oil pumps and enhances safety during steering.

[0040] Example 2:

[0041] This embodiment provides a dual-source oil pump control system. Figure 2 As shown, it includes a vehicle controller, a high-voltage system part and a low-voltage system part. The high-voltage system part serves as the main energy part, including a power battery, a high-voltage DC / AC controller and a high-voltage motor; the low-voltage system part serves as the emergency auxiliary energy part, including a battery, a low-voltage DC / AC controller and a low-voltage motor.

[0042] The dual-source oil pump is an electric-hydraulic power steering pump assembly for both high-pressure and low-pressure systems, assisting with vehicle steering. The vehicle controller is the "brain" of the new energy vehicle control system, providing real-time monitoring of the vehicle's status. The power battery provides high-voltage DC power for new energy vehicles. The high-voltage DC / AC controller converts the battery's DC power into AC power for the high-voltage motor, while the low-voltage DC / AC controller converts the battery's DC power into AC power for the low-voltage motor.

[0043] In this embodiment, signals are transmitted between the low-voltage motor, the low-voltage DC / AC controller, and the vehicle CAN bus. The low-voltage DC / AC controller sends the operating status, working state, motor speed, temperature, and other conditions via the CAN bus. The vehicle controller VCU performs real-time detection and adopts timely and effective emergency control strategies. Control signals such as high- and low-voltage switching and oil pump shutdown are transmitted to the oil pump via the CAN bus, achieving a good emergency control effect. The high-voltage motor and the low-voltage motor are coaxial dual-winding motors integrated in the dual-source power steering oil pump, occupying a small space and having high emergency control efficiency.

[0044] The working principle of this embodiment is:

[0045] When the vehicle starts, the system automatically detects whether the fuel pump is enabled. The vehicle controller sends information such as vehicle speed, and simultaneously sends information to the integrated power supply and instrument panel to confirm whether the fuel pump is enabled. If the fuel pump is operating normally, the system determines whether the high-voltage circuit is normal based on the vehicle's CAN bus. Specifically, if the CAN is normal, the system determines whether high-voltage power should be disconnected. Furthermore, if the fuel pump motor speed is less than the minimum low-voltage operating speed, the system determines whether to engage the battery emergency assist function. After the high-voltage power is disconnected and the low-voltage circuit is enabled, the fuel pump will operate normally for 3 minutes before the low-voltage controller shuts down. The driver must pull over within 3 minutes.

[0046] The above description is merely a preferred embodiment of the present application and is not intended to limit the present application. Various modifications and variations are possible for those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A dual-source oil pump control method, characterized in that: When the oil pump is working properly, determine whether the vehicle CAN bus is normal; when the CAN bus is normal, determine whether the high-voltage system is normal and whether the high-voltage power supply needs to be cut off; In the case of CAN abnormality, determine whether the low-voltage signal port receives a high level; When the high voltage system is partially abnormal and the fault is irrecoverable, and the vehicle speed is greater than the set value, or when the low voltage signal port receives a high level, the low voltage is enabled; When the oil pump is operating normally, the CAN bus communication is normal, and the high-voltage system of the vehicle is normal, the high-pressure oil pump will operate normally. When the high-pressure system is abnormal and the high-voltage DC / AC controller reports a recoverable fault, the high-pressure side oil pump is not allowed to shut down. When the high-pressure system is abnormal and the vehicle speed is greater than the set value, the low-voltage is enabled. When the high-pressure system is abnormal and the vehicle speed is greater than the set value, and the low-voltage DC / AC controller detects that the oil pump motor speed is lower than the set speed threshold, the battery emergency assist is activated. When the oil pump works normally, the CAN bus communication is abnormal and the vehicle speed is greater than the set value, the low-pressure oil pump starts when the low-voltage signal port receives a high level; when no high level is received, the high-pressure side oil pump continues to work.

2. A dual-source oil pump control method according to claim 1, characterized in that: In the low-voltage enabled state, when the oil pump motor speed is lower than the set speed threshold, the battery emergency assist is activated.

3. A dual-source oil pump control method according to claim 1, characterized in that: After the low-pressure oil pump is started, if it continues to run for the set time, the low-voltage DC / AC controller will automatically shut down; if the oil pump control power supply at the low-voltage signal port is directly cut off, the low-voltage DC / AC controller will shut down; if the vehicle controller and the low-voltage DC / AC controller lose CAN bus connection, the low-voltage hard-line enable at the low-voltage signal port will be powered off, and the low-voltage DC / AC controller will shut down.

4. A dual-source oil pump control method according to claim 1, characterized in that: When the vehicle is in the ON gear and the battery is not in the high-voltage state, the oil pump trigger button is pressed continuously for a set number of times. The vehicle controller forces the low-voltage DC / AC controller to be enabled. The low-voltage DC / AC controller detects that the motor speed is 0r / min and starts the low-voltage part after a set time.

5. A dual-source oil pump control method according to claim 1, characterized in that: When the high-voltage system is partially abnormal and the vehicle speed is greater than the set value, the vehicle loses high voltage, or the vehicle controller receives an unrecoverable fault signal from the high-voltage DC / AC controller at the same time within the same message cycle, the low voltage is enabled and the high-voltage DC / AC controller is disconnected.

6. A system for controlling a dual-source oil pump according to any one of claims 1 to 5, characterized in that: It includes a vehicle controller, a high-voltage system part and a low-voltage system part. The vehicle controller is connected to the high-voltage DC / AC controller and the power battery through the CAN bus. The control signal of the low-voltage DC / AC controller can be transmitted to the vehicle controller through the CAN bus to switch the working state of the oil pump.

7. The system of the dual-source oil pump control method according to claim 6, characterized in that: The high-voltage system includes a power battery, a high-voltage DC / AC controller and a high-voltage motor. The high-voltage DC / AC controller is used to convert the direct current of the power battery into alternating current for use by the high-voltage motor. The low-voltage system includes batteries, low-voltage DC / AC controllers and low-voltage motors. The low-voltage DC / AC controller is used to convert the direct current of the battery into alternating current for use by the low-voltage motor.

8. The system of the dual-source oil pump control method according to claim 7, characterized in that: The high-voltage motor and the low-voltage motor are coaxial double-winding motors, which are integrated in the dual-source power steering oil pump.

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