Power-assisted steering control method and system for new energy vehicle

Abstract

The invention discloses a new energy vehicle power-assisted steering control method and system, and belongs to the technical field of new energy vehicles. Comprising the steps of obtaining the maximum allowable output power of the high-voltage energy storage system; based on a comparison result of the maximum allowable output power and a preset gradient power threshold value, the running state of the new energy vehicle is determined; and determining a steering control strategy according to the running state of the new energy vehicle. Effective power-assisted steering can be continuously provided for the whole vehicle by quickly responding and identifying two states and quickly switching in, and the vehicle speed, the oil pump operation time, whether the whole vehicle has a steering demand, faults and storage battery voltage abnormity conditions are monitored in real time and processed in real time, so that the vehicle can safely drive out of a dangerous area when having faults, the vehicle speed is reduced to a safety threshold value, and the safety of the vehicle is ensured. And the oil pump stops working. The problem that safety risks are caused due to the fact that an existing new energy vehicle breaks down in the running process but double-source steering switching is not timely is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle control, and in particular to a steering assist control method and system for a new energy vehicle. Background Art

[0002] The statements in this section merely mention background art related to the present invention and do not necessarily constitute prior art.

[0003] With the continuous promotion of new energy vehicles, the sustainable operation and safety of vehicles have attracted much attention.

[0004] However, in actual application, when the vehicle is traveling at high speed, if the high voltage drops due to mechanical failure, high voltage system, power system failure, controller failure or other failures that cannot be immediately repaired, or the high voltage is lost in an unexpected state, the high voltage power assist is in failure mode, affecting the operating safety of new energy vehicles.

[0005] The response strategy adopted by most manufacturers is to identify the vehicle fault level and control the steering power according to the vehicle fault level; in case of serious fault, the high pressure is directly reduced, the high pressure oil pump fails, and the low pressure oil pump works. However, in this process, the judgment time is long, the strategy control is relatively simple, and the performance status of the vehicle itself is not predicted in advance, and the purpose of rapid identification and switching cannot be achieved, which may cause time delays and create the risk of safety accidents.

[0006] In addition, if a serious fault occurs in the high-voltage energy storage system, the discharge current is quickly limited. If the high-pressure oil pump is still in operation at this time, there is a risk of over-discharge and damage to the high-voltage energy storage device. Summary of the invention

[0007] In order to address the deficiencies in the prior art, the present invention provides a steering assist control method, system, electronic device, computer-readable storage medium and computer program product for a new energy vehicle, which reduces the probability of safety accidents caused by faults during the operation of the new energy vehicle.

[0008] In a first aspect, the present invention provides a method for controlling a power steering system for a new energy vehicle;

[0009] A power steering control method for a new energy vehicle, comprising:

[0010] Obtain the maximum allowable output power of the high-voltage energy storage system;

[0011] Based on the comparison result of the maximum allowable output power and the preset gradient power threshold, the operating state of the new energy vehicle is determined; and according to the operating state of the new energy vehicle, the steering control strategy is determined.

[0012] In some implementations, determining the operating state of the new energy vehicle based on the comparison result of the maximum allowable output power and the preset gradient power threshold specifically includes:

[0013] If the maximum allowable output power is greater than or equal to a preset first gradient power threshold, the new energy vehicle is in a normal state;

[0014] If the maximum allowable output power is greater than or equal to the preset second gradient power threshold and less than the preset first gradient power threshold, and the duration reaches the preset time threshold, the new energy vehicle is in a secondary fault state;

[0015] If the maximum allowable output power is greater than or equal to the preset third gradient power threshold and less than the preset second gradient power threshold, and the duration reaches the preset time threshold, the new energy vehicle is in a third-level fault state;

[0016] If the maximum allowable output power is less than the preset third gradient power threshold and the duration reaches the preset time threshold, the new energy vehicle is in a level 4 fault state.

[0017] In some implementations, determining and executing a steering control strategy according to the operating state of the new energy vehicle specifically includes:

[0018] If the operating state of the new energy vehicle is normal, a power-on command or an enable signal is sent to the high-voltage steering controller, and a power-off command is sent to the low-voltage steering controller;

[0019] If the operating state of the new energy vehicle is a secondary fault state, a startup command or an enable signal is sent to the high-voltage steering controller, a shutdown command is sent to the low-voltage steering controller, and a power limit command is sent to the vehicle power system and high-voltage accessories;

[0020] If the operating state of the new energy vehicle is a level 3 fault state, a startup command or an enable signal is sent to the high-voltage steering controller, a shutdown command is sent to the low-voltage steering controller, a power limit command is sent to the vehicle power system, and a disable command is sent to the high-voltage accessories;

[0021] If the operating state of the new energy vehicle is a level 4 fault state, a shutdown command or an enable signal is sent to the high-voltage steering controller, and a startup command is sent to the low-voltage steering controller.

[0022] In some embodiments, after the high-pressure controller receives the shutdown command, if it receives the steering demand command, it sends the oil pump shutdown status command to the vehicle controller, and the low-pressure steering controller starts working when the oil pump speed reaches a preset threshold.

[0023] In some embodiments, after the high-pressure controller receives the shutdown command, if it receives the steering demand command, it sends the oil pump shutdown status command to the vehicle controller, and the low-pressure steering controller starts working when the oil pump speed reaches a preset threshold.

[0024] In some embodiments, it further comprises:

[0025] Obtain vehicle speed, fuel pump operating time, steering requirements and battery voltage in real time;

[0026] If the vehicle speed is lower than a preset speed threshold, the steering demand is empty, or the oil pump operation time reaches a preset operation time threshold, a shutdown command is issued to the low-voltage steering controller;

[0027] If the battery voltage is lower than the preset voltage threshold, a battery abnormality instruction is sent to the meter.

[0028] In a second aspect, the present invention provides a power steering control system for a new energy vehicle;

[0029] A power steering control system for a new energy vehicle, comprising:

[0030] The vehicle controller is used to perform the following steps:

[0031] Obtain the maximum allowable output power of the high-voltage energy storage system;

[0032] Determining the operating state of the new energy vehicle based on the comparison result of the maximum allowable output power and the preset gradient power threshold; determining the steering control strategy according to the operating state of the new energy vehicle;

[0033] a high-voltage steering controller for performing control operations according to a steering control strategy;

[0034] A low voltage steering controller is used to perform control operations according to a steering control strategy.

[0035] In a third aspect, the present invention provides an electronic device;

[0036] An electronic device comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the above-mentioned new energy vehicle steering assist control method.

[0037] In a fourth aspect, the present invention provides a computer-readable storage medium;

[0038] A computer-readable storage medium stores a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned steering assist control method for new energy vehicles.

[0039] In a fifth aspect, the present invention provides a computer program product;

[0040] A computer program product includes a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned steering assist control method for new energy vehicles.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] 1. The technical solution provided by the present invention can provide effective steering assistance to the whole vehicle continuously through rapid response, identification of two states and rapid cut-in, and real-time monitoring of vehicle speed, oil pump operation time, whether the vehicle has steering demand, faults and abnormal battery voltage, and real-time processing, so that when a vehicle fails, it can safely drive out of the dangerous area and the oil pump stops working only when the vehicle speed drops to a safe threshold; the probability of safety accidents caused by faults in new energy vehicles during operation is reduced.

[0043] 2. The technical solution provided by the present invention is developed through the research and development of control strategies, and the vehicle fault power limiting processing strategy and reasonable vehicle power distribution strategy are implanted to predict in advance the range of the vehicle power, fully ensuring the protection of the key components and performance of the vehicle. By being able to quickly switch between the high and low pressure states of the oil pump, the steering safety of the vehicle is also greatly improved. At the same time, when the oil pump is in a low pressure state, the working state of the oil pump in a low pressure state is controlled by monitoring the vehicle speed, running time, and steering requirements. At the same time, by monitoring the battery voltage, the battery voltage is prevented from being depleted, so that the vehicle can operate sustainably. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] The accompanying drawings in the specification, 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.

[0045] Figure 1 A schematic diagram of a flow chart provided for an embodiment of the present invention. DETAILED DESCRIPTION

[0046] It should be noted that the following detailed descriptions are exemplary and are intended to provide further explanation of the present invention. Unless otherwise specified, all technical and scientific terms used in the present invention have the same meanings as those commonly understood by those skilled in the art to which the present invention belongs.

[0047] It should be noted that the terms used herein are only for describing specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that the terms "include" and "have" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0048] In the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0049] Embodiment 1

[0050] Next, combine Figure 1 , a steering assist control method for a new energy vehicle disclosed in this embodiment is described in detail. The steering assist control method for a new energy vehicle is applied to a vehicle controller and includes the following steps:

[0051] S1. Obtain the maximum allowable output power P of the high-voltage energy storage system max .

[0052] In this embodiment, the BMS system transmits the maximum allowable output power P to the max Sent to the vehicle controller.

[0053] S2, based on the maximum allowable output power P max The operating state of the new energy vehicle is determined by comparing the result with the preset gradient power threshold; and the steering control strategy is determined according to the operating state of the new energy vehicle.

[0054] Specifically, if the maximum allowable output power P max is greater than or equal to the preset first gradient power threshold P1, the new energy vehicle is in a normal state and S3 is executed; if the maximum allowable output power P max If the maximum allowable output power P is greater than or equal to the preset second gradient power threshold P2 and less than the preset first gradient power threshold P1, and the duration reaches the preset time threshold, the new energy vehicle is in a secondary fault state and S4 is executed; if the maximum allowable output power P max If the maximum allowable output power P is greater than or equal to the preset third gradient power threshold P3 and less than the preset second gradient power threshold P2, and the duration reaches the preset time threshold, the new energy vehicle is in a third-level fault state and executes S5; if the maximum allowable output power P max If the power consumption of the new energy vehicle is less than the preset third gradient power threshold P3 and the duration reaches the preset time threshold, the new energy vehicle is in a level 4 fault state and S6 is executed.

[0055] Here, the time threshold is 5S.

[0056] In this embodiment, the first gradient power threshold P1, the second gradient power threshold P2 and the third gradient power threshold P3 are power lower limits pre-calibrated by the operation and maintenance personnel based on work experience and vehicle performance. The first gradient power threshold P1> the second gradient power threshold P2> the third gradient power threshold P3.

[0057] When the vehicle is in a normal state and the vehicle functions are in normal use, when it is identified that the high-voltage energy storage system can allow the output power to be reduced within the first, second or third threshold range, the corresponding control strategy is executed to protect the entire vehicle.

[0058] S3. Send a power-on command to the high-pressure steering controller so that the high-pressure steering controller controls the operation of the high-pressure oil pump, the steering system has high-pressure power assistance, and the steering wheel is easy to operate; send a power-off command to the low-pressure steering controller. At the same time, the vehicle's high-pressure system, power system, and high-pressure accessories maintain normal operation.

[0059] The enable signal is a control signal, that is, the binary command in the controller outputs high and low levels to realize power supply (negative control relays open and close to realize power supply), so as to realize power supply to the corresponding components. After the components are powered on, their execution strategies are judged and executed according to their own conditions. The selection of commands and enable signals can be determined according to customer needs.

[0060] In this embodiment, the high-voltage steering controller is started by controlling the power-on command. The power-on command is sent in the form of a message through the CAN network bus. After receiving the command through the CAN bus, the corresponding component controls the hard line to send an enable signal to energize. Its execution strategy is executed according to its own situation. S4. Send a power-on command to the high-voltage steering controller so that the high-voltage steering controller controls the operation of the high-voltage oil pump, the steering system still has high-voltage power assistance, and the steering wheel is easy to operate; send a shutdown command to the low-voltage steering controller; at the same time, send a power limit command to the vehicle power system and high-voltage accessories, limiting the vehicle power system and high-voltage accessories to 70%.

[0061] Limiting power can avoid quality problems such as wiring harness burning and motor damage caused by excessive current, and protect key vehicle components from damage; during continuous acceleration or high-intensity use, limiting power can prevent the motor from overheating and avoid damage to the motor caused by long-term high-power operation; limit the output power of the battery in the vehicle's power system to protect battery life and safety, and avoid premature battery damage due to excessive use; ensure the overall performance and stability of the vehicle.

[0062] S5. Send a power-on command to the high-pressure steering controller so that the high-pressure steering controller controls the operation of the high-pressure oil pump. The steering system still has high-pressure power assistance and the steering wheel is easy to operate. Send a power-off command to the low-pressure steering controller. At the same time, send a power-limiting command to the vehicle power system to limit its power to 20%. Send a disabling command to the high-pressure accessories to prohibit the use of the high-pressure accessories.

[0063] S6. Send a shutdown command to the high-pressure steering controller, so that the high-pressure steering controller sends a shutdown command to the oil pump, and the oil pump motor slows down; send a startup command to the low-pressure steering controller, so that the low-pressure steering controller controls the operation of the oil pump and the power assist intervenes.

[0064] When the vehicle is in a level 4 fault state, the power system power source is interrupted, high-voltage accessories are prohibited from use, and high voltage is lost, posing a major safety hazard.

[0065] As an implementation method, the low-pressure steering controller controls the operation of the low-pressure oil pump in combination with the steering demand issued by the vehicle controller. Specifically, when the vehicle controller has a steering demand and the high-pressure steering controller has reported a shutdown, the low-pressure steering controller starts to work from the oil pump speed nr / min; when the vehicle controller has a steering demand and the high-pressure steering controller has not reported the oil pump shutdown, the low-pressure steering controller detects that the oil pump speed has dropped to 0 and starts working.

[0066] In this embodiment, n is 500.

[0067] As an implementation method, after the low-voltage steering controller intervenes, it also includes: obtaining the vehicle speed, oil pump running time, steering demand and battery voltage in real time; if the vehicle speed is lower than a preset speed threshold, the steering demand is empty or the oil pump running time reaches a preset running time threshold, a shutdown command is issued to the low-voltage steering controller; if the battery voltage is lower than a preset voltage threshold, a battery abnormality command is sent to the instrument.

[0068] Specifically, after the low-voltage steering controller intervenes, the steering system of the vehicle assists normally. The vehicle controller starts to monitor the vehicle speed, oil pump operation time, whether the vehicle has a continuous steering demand, and the battery voltage from the moment the low voltage intervenes. When the vehicle speed is lower than 5km / h or the vehicle has no steering demand or the oil pump operation time reaches 2min, if any of the conditions are met, the low-voltage steering controller controls the oil pump to shut down. In addition, if the battery voltage is detected to be less than 20v during the operation of the oil pump, the instrument reports that the battery voltage is abnormal, and it is necessary to power up and repair as soon as possible, or repair the fault as soon as possible to power on the vehicle normally. If the vehicle is in a low-voltage state, it is automatically recharged through the step-down DCDC. When the battery voltage is greater than or equal to 22.5V, the recharging stops or the strategy is executed for 30min. If the vehicle is in a high-voltage state, it is automatically recharged through the step-down DCDC to continuously maintain the battery voltage at greater than or equal to 24V.

[0069] Embodiment 2

[0070] Based on Example 1, this embodiment discloses a new energy vehicle steering power control system, including a vehicle controller, a steering system, a high-voltage energy storage system, a low-voltage battery, a step-down DCDC, and a dual-source power detection controller. The steering system includes a high-voltage steering controller, a low-voltage steering controller, and a steering oil pump. The high-voltage energy storage system includes a high-voltage energy storage unit and a battery management system (BMS); the vehicle controller, the high-voltage steering controller, the low-voltage steering controller, the BMS and other controllers, the step-down DCDC, and the dual-source power detection controller communicate and exchange information through a CAN line.

[0071] The vehicle controller is used to obtain the maximum allowable output power of the high-voltage energy storage system; determine the operating status of the new energy vehicle based on the comparison result of the maximum allowable output power and the preset gradient power threshold; determine the steering control strategy according to the operating status of the new energy vehicle; the high-voltage steering controller receives instructions / enables to provide steering assistance to the steering wheel of the vehicle after the high voltage is applied to the vehicle; the low-pressure power-assisting oil pump is started according to the needs of the vehicle when the high voltage is lost after a serious fault of the vehicle, and the high-voltage steering controller stops working, and starts the low-voltage steering controller to provide steering assistance to the steering wheel of the vehicle. The high-voltage energy storage system is connected to the high-voltage steering controller through a high-voltage line, and the high-voltage steering controller is connected to the high-voltage end of the oil pump; the low-voltage battery is connected to the low-voltage steering controller through a low-voltage wiring harness, and the low-voltage steering controller is connected to the low-voltage end of the oil pump.

[0072] The battery is also connected to the step-down DCDC through a low-voltage line, and the step-down DCDC is connected to the high-voltage energy storage system through a high-voltage line.

[0073] Embodiment 3

[0074] Embodiment 3 of the present invention provides an electronic device, including a memory and a processor, and computer instructions stored in the memory and running on the processor. When the computer instructions are run by the processor, the steps of the above-mentioned new energy vehicle steering assist control method are completed.

[0075] Embodiment 4

[0076] Embodiment 4 of the present invention provides a computer-readable storage medium for storing computer instructions. When the computer instructions are executed by a processor, the steps of the above-mentioned new energy vehicle steering assist control method are completed.

[0077] Embodiment 5

[0078] Embodiment 5 of the present invention provides a computer program product, including a computer program / instruction, which implements the steps of the above-mentioned new energy vehicle steering assist control method when executed by a processor.

[0079] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0080] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0081] These computer program instructions can also be loaded onto a computer or other programmable data processing device, and a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0082] The description of each embodiment in the above embodiments has different emphases. For parts not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0083] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A steering assist control method for a new energy vehicle, characterized in that: include: Obtain the maximum allowable output power of the high-voltage energy storage system; Based on the comparison result of the maximum allowable output power and the preset gradient power threshold, the operating state of the new energy vehicle is determined; and according to the operating state of the new energy vehicle, the steering control strategy is determined.

2. The power steering control method for new energy vehicles according to claim 1, characterized in that: The determining the operating state of the new energy vehicle based on the comparison result of the maximum allowable output power and the preset gradient power threshold specifically includes: If the maximum allowable output power is greater than or equal to a preset first gradient power threshold, the new energy vehicle is in a normal state; If the maximum allowable output power is greater than or equal to the preset second gradient power threshold and less than the preset first gradient power threshold, and the duration reaches the preset time threshold, the new energy vehicle is in a secondary fault state; If the maximum allowable output power is greater than or equal to the preset third gradient power threshold and less than the preset second gradient power threshold, and the duration reaches the preset time threshold, the new energy vehicle is in a third-level fault state; If the maximum allowable output power is less than the preset third gradient power threshold and the duration reaches the preset time threshold, the new energy vehicle is in a level 4 fault state.

3. The power steering control method for new energy vehicles according to claim 1, characterized in that: Determining and executing the steering control strategy according to the operating state of the new energy vehicle specifically includes: If the operating state of the new energy vehicle is normal, a power-on command or an enable signal is sent to the high-voltage steering controller, and a power-off command is sent to the low-voltage steering controller; If the operating state of the new energy vehicle is a secondary fault state, a startup command or an enable signal is sent to the high-voltage steering controller, a shutdown command is sent to the low-voltage steering controller, and a power limit command is sent to the vehicle power system and high-voltage accessories; If the operating state of the new energy vehicle is a level 3 fault state, a startup command or an enable signal is sent to the high-voltage steering controller, a shutdown command is sent to the low-voltage steering controller, a power limit command is sent to the vehicle power system, and a disable command is sent to the high-voltage accessories; If the operating state of the new energy vehicle is a level 4 fault state, a shutdown command or an enable signal is sent to the high-voltage steering controller, and a startup command is sent to the low-voltage steering controller.

4. The power steering control method for new energy vehicles as claimed in claim 3, characterized in that: After the high-pressure controller receives the shutdown command, if it receives the steering demand command, it sends the oil pump shutdown status command to the vehicle controller, and the low-pressure steering controller starts working when the oil pump speed reaches the preset threshold.

5. The power steering control method for new energy vehicles as claimed in claim 3, characterized in that: After the high-pressure controller receives the shutdown command, if it receives the steering demand command, it sends the oil pump shutdown status command to the vehicle controller, and the low-pressure steering controller starts working when the oil pump speed reaches the preset threshold.

6. The power steering control method for new energy vehicles according to claim 1, characterized in that: Also includes: Obtain vehicle speed, fuel pump operating time, steering requirements and battery voltage in real time; If the vehicle speed is lower than a preset speed threshold, the steering demand is empty, or the oil pump operation time reaches a preset operation time threshold, a shutdown command is issued to the low-voltage steering controller; If the battery voltage is lower than the preset voltage threshold, a battery abnormality instruction is sent to the meter.

7. A power steering control system for new energy vehicles, characterized in that: include: The vehicle controller is used to perform the following steps: Obtain the maximum allowable output power of the high-voltage energy storage system; Determining the operating state of the new energy vehicle based on the comparison result of the maximum allowable output power and the preset gradient power threshold; determining the steering control strategy according to the operating state of the new energy vehicle; a high-voltage steering controller for performing control operations according to a steering control strategy; A low voltage steering controller is used to perform control operations according to a steering control strategy.

8. An electronic device comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the steering assist control method for a new energy vehicle according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the steering assist control method for a new energy vehicle described in any one of claims 1 to 6 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the steering assist control method for a new energy vehicle described in any one of claims 1 to 6 are implemented.

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