Intelligent control method for power‑assisted steering system of pure electric mining vehicle

Abstract

The present invention relates to the technical field of vehicle steering control, and provides an intelligent control method for a power‑assisted steering system of a pure electric mining vehicle. The method comprises: when a driver turns on an intelligent start-stop switch of a power‑assisted steering system, entering a power‑assisted steering pump automatic start-stop system; a VCU detecting the vehicle system state in real time, and determining whether steering stop conditions are simultaneously satisfied; when the steering stop conditions are simultaneously satisfied, the power-assisted steering system stopping; and when the steering stop conditions are not simultaneously satisfied, the power-assisted steering system entering a long-duration working state. In the present invention, a driver's demand for steering can be intelligently determined, start and stop of the steering system can be intelligently controlled, and energy consumption can be reduced; when the vehicle is stopped for waiting, the system is stopped to reduce driver cabin noise; when high-voltage and low-voltage power-assisted steering systems fail simultaneously, the driver will be prompted to immediately stop the vehicle; when high-voltage steering fails, low-voltage power-assisted steering will be automatically started, unlike conventional methods in which the low-voltage power-assisted steering system needs to be manually started, thereby avoiding operational errors.

Description

An intelligent control method based on a power-assisted steering system of a pure electric mine truck TECHNICAL FIELD

[0001] The application belongs to the technical field of automobile steering control, and specifically relates to an intelligent control method based on a power-assisted steering system of a pure electric mine truck. BACKGROUND

[0002] Electric engineering machinery is one of important parts to achieve the national double carbon strategy. The pure electric mine truck has great environmental protection and economic advantages compared with the fuel mine truck. Since the mine truck has a large load, the driver's strength alone cannot complete the steering operation in the steering operation, and the power-assisted steering system provides additional power for the driver to operate the mine truck steering, so the power-assisted steering system plays an important role in the safe operation of the mine truck.

[0003] The existing mine truck steering system is a hydraulic steering system, the fuel mine truck uses an engine to drive an oil pump to provide steering power, and the pure electric mine truck uses a high-voltage battery + motor to drive a high-pressure oil pump to provide steering power. In the high-voltage state of the vehicle (normal driving or temporary parking), the high-pressure power pump is always working, causing energy waste; in the parking state, the high-pressure oil pump works to produce noise pollution, which is harmful to the driver's health; after the failure of the high-pressure steering system, the driver needs to manually start the emergency steering system, which is prone to operation errors and has safety hazards. SUMMARY

[0004] 1. Technical problem to be solved by the application

[0005] The application aims to solve the problem of invalid work of the existing mine truck high-pressure oil pump, causing energy waste and noise pollution, and secondly, to solve the problem that the driver needs to manually operate the emergency steering system after the failure of the existing high-pressure system.

[0006] 2. Technical scheme

[0007] To achieve the above-mentioned purpose, the technical scheme provided by the application is as follows:

[0008] The intelligent control method based on the power-assisted steering system of the pure electric mine truck provided by the application specifically includes the following steps:

[0009] S1, power on the power-assisted steering system in high pressure;

[0010] S2, the vehicle VCU detects the state of the power-assisted steering system intelligent start-stop switch in real time, if the driver does not turn on the power-assisted steering system intelligent start-stop switch, step S3 is executed; if the driver turns on the power-assisted steering system intelligent start-stop switch, step S4 is executed;

[0011] S3, if the driver does not open the intelligent start-stop switch of the power steering system, the power steering oil pump works for a long time, and step S2 is repeatedly executed;

[0012] S4, when the driver opens the intelligent start-stop switch of the power steering system, the instrument prompts "steering start-stop is on", and the automatic start-stop system of the power steering oil pump is entered;

[0013] S5, the vehicle VCU detects the vehicle system state in real time, and judges whether the steering stop conditions are met at the same time, if the steering stop conditions are met at the same time, step S6 is executed; if the steering stop conditions are not met at the same time, step S7 is executed;

[0014] S6, when the vehicle VCU detects that the vehicle system meets the steering stop conditions at the same time, the power steering system stops, the instrument prompts "steering is stopping, please step on the brake to start", and step S5 is repeatedly executed;

[0015] S7, when the vehicle VCU detects that the vehicle system does not meet the steering stop conditions at the same time, the power steering system enters a long-time working state and step S5 is repeatedly executed.

[0016] Preferably, in step S5, the steering stop conditions are specifically:

[0017] 1) the stop switch is opened;

[0018] 2) the vehicle is parked, and the vehicle parked is specifically that the vehicle speed is less than a threshold (0.5, 1) kmph, the threshold (0.5, 1) is a threshold hysteresis, and the accurate meaning is that when the vehicle speed is lower than 0.5 kmph, the vehicle speed changes to be higher than 1 kmph to be considered to exit the parking state; when the vehicle speed is higher than 1 kmph, the vehicle speed changes to be lower than 0.5 kmph to enter the parking state, that is, between 0.5-1 kmph, the vehicle always maintains the last state until the threshold is broken to become the next state;

[0019] 3) the current gear is in N gear;

[0020] 4) the parking system is in parking;

[0021] 5) the brake pedal is not stepped on, and the brake pedal observation value is less than a threshold (5%, 7%), the threshold (5%, 7%) is a threshold hysteresis, and the accurate meaning is that when the brake pedal observation value is less than 5%, only the brake pedal observation value changes to be greater than 7% to indicate that the brake pedal is stepped on, when the brake pedal observation value is greater than 7%, only the brake pedal observation value changes to be less than 5% to indicate that the brake pedal is not stepped on, that is, between 5%-7%, the vehicle always maintains the last state until the threshold is broken to become the next state;

[0022] 6) Accelerator pedal is not stepped on, and the accelerator pedal observation value is less than a threshold value (5%, 7%), which is a threshold hysteresis. The accurate meaning is that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to be greater than 7% does it indicate that the accelerator pedal is stepped on; when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to be less than 5% does it indicate that the accelerator pedal is not stepped on, that is, between 5% and 7%, the vehicle always remains in the previous state until the threshold is broken to become the next state;

[0023] 7) The steering wheel rotation angle is less than 45 degrees;

[0024] 8) The steering wheel rotation angular velocity is less than 5 degrees / s.

[0025] Preferably, the power steering system comprises a high-pressure power steering system and a low-pressure power steering system, and the power steering system in step S7 enters a long-time working state, specifically:

[0026] S71, the power steering system receives a working request;

[0027] S72, the vehicle VCU detects the high-pressure power steering system to determine whether the high-pressure power steering system has a fault, if the high-pressure power steering system has no fault, step S73 is executed; if the high-pressure power steering system has a fault, step S74 is executed;

[0028] S73, the high-pressure power steering system is started, and step S72 is executed at the same time;

[0029] S74, the high-pressure power steering system has a fault, and the instrument prompts "steering fault, please park safely", and the vehicle VCU detects the low-pressure power steering system, if the low-pressure power steering system has no fault, step S75 is executed; if the low-pressure power steering system has a fault, step S76 is executed;

[0030] S75, the low-pressure power steering system is started, and step S74 is executed, and the vehicle VCU detects the 24V storage battery voltage value, when the voltage value is lower than a threshold value (20, 24), it prompts "steering fault, please park immediately", the threshold value (20, 24) is a threshold hysteresis, when the 24V storage battery voltage value is less than 20V, only when the 24V storage battery voltage value changes to be greater than 24V can the 24V storage battery supply power; when the 24V storage battery voltage value is greater than 24V, only when the 24V storage battery voltage value changes to be less than 20V can the 24V storage battery stop supplying power, that is, between 20V and 24V, the vehicle always remains in the previous state until the threshold is broken to become the next state;

[0031] S76, the low-pressure power steering system has a fault, the instrument prompts "steering failure, please stop immediately", and the vehicle VCU detects the driver's operation, when the vehicle VCU detects that the driver's operation meets any braking condition, step S77 is executed, when the vehicle VCU detects that the driver's operation does not meet any braking condition, step S76 is continued;

[0032] S77, the full braking mode is started.

[0033] Preferably, the braking condition in step S76 is specifically:

[0034] 1) the driver has a braking intention, the brake pedal observation value is greater than a threshold value (5%, 7%), the threshold value (5%, 7%) is a threshold hysteresis, when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to be greater than 7%, it is indicated that the brake pedal is stepped on; when the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to be less than 5%, it is indicated that the brake pedal is not stepped on, that is, between 5% and 7%, the vehicle always maintains the previous state until the threshold is broken to become the next state;

[0035] 2) the parking brake (hand brake or electronic EPB) has a braking or parking request;

[0036] 3) the electric eddy current brake is started by the driver;

[0037] 4) the energy feedback gear is in the highest gear.

[0038] Preferably, the full braking mode in step S77 is specifically:

[0039] 1) when the vehicle speed is greater than a threshold value (5, 7) kmph, the motor braking is started;

[0040] 2) the motor braking deceleration value and the maximum deceleration value under the current vehicle speed are compared, if the motor braking deceleration value is less than the maximum deceleration value, the motor braking is started and the mechanical braking is applied in proportion until the maximum deceleration value is reached;

[0041] 3) when the vehicle speed is less than a threshold value (5, 7) kmph, the mechanical braking is started for parking until the driver performs the forward torque output operation, that is, the accelerator pedal is stepped on to the accelerator pedal observation value greater than a threshold value (5%, 7%);

[0042] When the vehicle speed is lower than 5Kmph, mechanical braking is used, and when the vehicle speed is higher than 7Kmph, motor braking is used; the threshold (5, 7) is a threshold hysteresis, and the accurate meaning is that when the vehicle speed is lower than 5Kmph, the vehicle speed changes to be greater than 7Kmph to exit the mechanical braking and start the motor braking; when the vehicle speed is greater than 7Kmph, the vehicle speed changes to be lower than 5Kmph to exit the motor braking and start the mechanical braking, that is, between 5Kmph and 7Kmph, the vehicle always keeps the last state until the threshold is broken to become the next state.

[0043] 3. Beneficial effects

[0044] Compared with the prior art, the technical scheme provided by the application has the following beneficial effects:

[0045] The intelligent control method of the power-assisted steering system of the pure electric mine vehicle provided by the application comprises the following steps: when the driver turns on the intelligent start-stop switch of the power-assisted steering system, the power-assisted steering pump automatic start-stop system is entered; the vehicle VCU detects the vehicle system state in real time and judges whether the steering stop conditions are met simultaneously; when the steering stop conditions are met simultaneously, the power-assisted steering system is stopped; and when the steering stop conditions are not met simultaneously, the power-assisted steering system enters a long-time working state. The application can intelligently judge the driver's demand for steering, intelligently control the start and stop of the steering system, and reduce energy consumption; when parking and waiting, the system is stopped to reduce the noise in the cab; when the high-voltage and low-voltage power-assisted steering systems fail simultaneously, immediate parking is prompted; and when the high-voltage steering fails, the low-voltage power-assisted steering is automatically started, instead of manually starting the low-voltage power-assisted steering system as in the traditional way, so that operation errors are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0046] Fig. 1 is a flowchart of the intelligent control method of the power-assisted steering system of the pure electric mine vehicle provided by the application;

[0047] Fig. 2 is a flowchart of the process in which the power-assisted steering system enters a long-time working state in the S7 step of the application;

[0048] Fig. 3 is a structural schematic diagram of the power-assisted steering system provided by the application. DETAILED DESCRIPTION

[0049] In order to enable personnel in the technical field to better understand the application scheme, the technical scheme in the application examples will be clearly and completely described below in combination with the drawings in the application examples. Obviously, the described examples are only a part of the examples of the application, rather than all the examples. Based on the examples in the application, all other examples obtained by those skilled in the art without creative labor should belong to the protection scope of the application.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above drawings are used to distinguish similar objects, and do not necessarily have to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be combined. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device that includes a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0051] In the present application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inner", "outer", "middle", "vertical", "horizontal", "lateral", "longitudinal", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not intended to limit the indicated devices, elements or components to have a specific orientation, or to be constructed and operated in a specific orientation.

[0052] In addition, in addition to indicating the orientation or positional relationship, the above-mentioned partial terms can also be used to indicate other meanings, for example, the term "upper" can also be used to indicate a certain dependent relationship or connection relationship in some cases. For those skilled in the art, the specific meaning of these terms in the present application can be understood according to the specific circumstances.

[0053] In addition, the terms "mount", "set", "provided with", "connected", "connected", "sleeved" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or a monolithic structure; it can be a mechanical connection, or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or internal communication between two devices, elements or components. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0054] It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the drawings and in combination with the embodiments.

[0055] Embodiment 1

[0056] With reference to the accompanying drawings 1-3, the intelligent control method of a pure electric mine truck based power steering system of the present embodiment, the power steering system used in the method provides additional power for the driver to operate the mine truck steering, so that the driver can simplify the operation in the process of operating the mine truck steering, the power steering system includes a high-voltage power steering system and a low-voltage power steering system, the high-voltage power steering system is powered by a power battery, and the power battery supplies power to a high-voltage steering motor through a power distribution cabinet, the high-voltage steering motor drives a high-voltage oil pump to provide hydraulic oil for the steering system to support steering work, the low-voltage power steering system is powered by a vehicle-mounted low-voltage storage battery, and directly supplies power to a low-voltage steering motor, the low-voltage steering motor drives a low-voltage oil pump to provide hydraulic oil for the steering system to support steering work, in the high-voltage state, the vehicle-mounted low-voltage storage battery is powered by a DCDC converter, and at the same time, the low-voltage power steering system is provided with energy; in the low-voltage state, the vehicle-mounted low-voltage storage battery directly provides energy. The power steering system contains an intelligent start-stop function for intelligent assistance of the power steering system, which reduces the operation steps of the driver, and the intelligent start-stop function can only be used in the high-voltage state; the power steering oil pump is the high-voltage oil pump in the high-voltage power steering system and the low-voltage oil pump in the low-voltage power steering system.

[0057] The method specifically includes the following steps:

[0058] S1, power on the high-voltage power steering system;

[0059] S2, the vehicle VCU detects the state of the power steering system intelligent start-stop switch in real time, if the driver does not turn on the power steering system intelligent start-stop switch, step S3 is executed; if the driver turns on the power steering system intelligent start-stop switch, step S4 is executed;

[0060] S3, if the driver does not turn on the power steering system intelligent start-stop switch, the power steering oil pump works for a long time, and step S2 is repeatedly executed;

[0061] S4, when the driver turns on the power steering system intelligent start-stop switch, the instrument prompts "steering start-stop is on", and the power steering oil pump automatic start-stop system is entered;

[0062] S5, the vehicle VCU detects the state of the vehicle system in real time, and judges whether the steering stop conditions are met at the same time, if the steering stop conditions are met at the same time, step S6 is executed; if the steering stop conditions are not met at the same time, step S7 is executed;

[0063] S6, when the vehicle system meets the steering stop condition, the power steering system stops, and the instrument prompts "steering stop, please step on the brake to start", and the step S5 is repeated, at this time, the power steering system is in the stop state, the energy loss is reduced, the noise is reduced, the driver in the cab is not disturbed by the noise, and the driving comfort is improved;

[0064] S7, when the vehicle system does not meet the steering stop condition, the power steering system enters the long-time working state and the step S5 is repeated.

[0065] In the step S5, the steering stop condition is specifically:

[0066] 1) the stop switch is turned on;

[0067] 2) the vehicle is parked, and the vehicle parked is specifically that the vehicle speed is less than a threshold (0.5, 1) kmph; when the vehicle speed is lower than 0.5 kmph, it is a parked state; when the vehicle speed is higher than 1 kmph, the parked state is exited, the threshold (0.5, 1) is a threshold hysteresis, setting the threshold hysteresis can effectively avoid the parked state fluctuation caused by the vehicle speed jitter, and when the vehicle speed is lower than 0.5 kmph, the vehicle has almost been in a stationary state, and the EPB can be parked smoothly, the threshold hysteresis is generally divided into two directions, changes from small to large or changes from large to small, and the accurate meaning is that when the vehicle speed is lower than 0.5 kmph, the vehicle speed changes to be higher than 1 kmph to be considered to exit the parked state; when the vehicle speed is higher than 1 kmph, the vehicle speed changes to be lower than 0.5 kmph to be considered to enter the parked state, that is, between 0.5-1 kmph, the vehicle always maintains the previous state until the threshold is broken to become the next state;

[0068] 3) the current gear is in N gear;

[0069] 4) the parking system is in parking;

[0070] 5) the brake pedal is not stepped on, and a brake pedal observation value is less than (5%, 7%), the brake pedal observation value is a quantity representing the depth of the brake pedal stepped on by the driver, generally a voltage signal or a percentage signal, when the brake pedal observation value is less than 5%, it is considered that the brake pedal is not stepped on, and when the brake pedal observation value is greater than 7%, it is considered that the brake pedal is stepped on, the threshold (5%, 7%) is a threshold hysteresis, setting the threshold (5%, 7%) can effectively avoid the parked state fluctuation caused by the vehicle speed jitter, and the accurate meaning is that when the brake pedal observation value is less than 5%, only the brake pedal observation value changes to be greater than 7% to indicate that the brake pedal is stepped on, when the brake pedal observation value is greater than 7%, only the brake pedal observation value changes to be less than 5% to indicate that the brake pedal is not stepped on, that is, between 5%-7%, the vehicle always maintains the previous state until the threshold is broken to become the next state.

[0071] 6) Accelerator pedal is not stepped on, accelerator pedal observation value is less than (5%, 7%), the accelerator pedal observation value is a quantity representing the depth of the accelerator pedal stepped on by the driver, generally using a voltage signal or a percentage signal, when the accelerator pedal observation value is less than 5%, it is considered that the accelerator pedal is not stepped on, when the accelerator pedal observation value is greater than 7%, it is considered that the accelerator pedal is stepped on; the threshold (5%, 7%) is a threshold hysteresis, the accurate meaning is that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to be greater than 7%, it is indicated that the accelerator pedal is stepped on, when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to be less than 5%, it is indicated that the accelerator pedal is not stepped on, that is, between 5% and 7%, the vehicle always maintains the last state until the threshold is broken to become the next state;

[0072] 7) Steering wheel rotation angle is less than 45 degrees;

[0073] 8) Steering wheel rotation angular velocity is less than 5 degrees / s.

[0074] When the vehicle VCU detects that all the above parking conditions are met, the vehicle VCU sends a parking signal to the power steering system, and the power steering system stops after receiving the signal, reducing the energy waste and noise generated by the power steering system in the parking state, and improving the comfort of the driver when working in the cab.

[0075] The power steering system in step S7 enters a long-time working state, specifically:

[0076] S71, the power steering system receives a working request;

[0077] S72, the vehicle VCU detects the high-pressure power steering system to detect whether the high-pressure power steering system has a fault, if the high-pressure power steering system has no fault, step S73 is executed; if the high-pressure power steering system has a fault, step S74 is executed;

[0078] S73, the high-pressure power steering system is started to assist the driver in steering operation, and step S72 is executed at the same time;

[0079] S74, the high-pressure power steering system has a fault, the instrument prompts "steering fault, please park safely", and the vehicle VCU detects the low-pressure power steering system, if the low-pressure power steering system has no fault, step S75 is executed; if the low-pressure power steering system has a fault, step S76 is executed;

[0080] S75, the low-pressure power steering system is started to assist the driver in steering operation, and step S74 is performed, while the vehicle VCU detects the 24V battery voltage value, the 24V battery is a vehicle-mounted low-voltage battery, and the low-pressure power steering system is powered, when the voltage value is lower than the threshold value (20, 24), the low-pressure power steering system cannot work, and a prompt "steering failure, please stop immediately" is given, when the voltage value is lower than the threshold value, step S76 is performed; when the voltage value is not lower than the threshold value, step S74 is continuously performed; the threshold value (20, 24) is a threshold hysteresis, when the 24V battery voltage value is less than 20V, only when the 24V battery voltage value changes to be greater than 24V, the 24V battery can be powered; when the 24V battery voltage value is greater than 24V, only when the 24V battery voltage value changes to be less than 20V, the 24V battery stops powering, that is, between 20 and 24, the vehicle always maintains the previous state until the threshold value is broken to become the next state;

[0081] S76, the low-pressure power steering system has a fault, and the instrument prompts "steering failure, please stop safely", at this time, the power steering system has a fault and cannot be used, when the driver encounters an emergency, the full braking mode needs to be turned on, the vehicle VCU detects the driver's operation, when the vehicle VCU detects that the driver's operation meets any braking condition, step S77 is performed, when the vehicle VCU detects that the driver's operation does not meet any braking condition, step S76 is continuously performed;

[0082] S77, the full braking mode is turned on.

[0083] The braking condition in step S76 is specifically:

[0084] 1) The driver has a braking intention, and the brake pedal observation value is greater than (5%, 7%), the brake pedal observation value is a quantity representing the depth of the brake pedal stepped on by the driver, generally a voltage signal or a percentage signal is used, when the brake pedal observation value is less than 5%, it is considered that the brake pedal is not stepped on, and when the brake pedal observation value is greater than 7%, it is considered that the brake pedal is stepped on; the threshold value (5%, 7%) is a threshold hysteresis, when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to be greater than 7%, it is indicated that the brake pedal has been stepped on, and when the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to be less than 5%, it is indicated that the brake pedal is not stepped on, that is, between 5% and 7%, the vehicle always maintains the previous state until the threshold value is broken to become the next state

[0085] 2) The parking brake (hand brake or electronic EPB) has a braking or parking request;

[0086] 3) The eddy current retarder is turned on by the driver;

[0087] 4) Energy feedback gear is in the highest gear.

[0088] The full braking mode in step S77 is specifically:

[0089] 1) When the vehicle speed is greater than the threshold (5, 7) kmph, start the motor braking, which is specifically to apply a torque on the motor rotating shaft in the opposite direction of the rotating direction, so as to rapidly decelerate or stop the system, i.e. using the motor reverse force braking to convert mechanical energy into electrical energy;

[0090] 2) Compare the motor braking deceleration value with the maximum deceleration value at the current vehicle speed, if the motor braking deceleration value is less than the maximum deceleration value, start the motor braking and apply the mechanical braking in proportion until the maximum deceleration value is reached, the mechanical braking is mainly to use the electric mine truck brake device to decelerate or stop;

[0091] 3) When the vehicle speed is less than the threshold (5, 7) kmph, start the mechanical braking to stop, until the driver performs the forward torque output operation, which is that the driver steps on the accelerator pedal, when the accelerator pedal observation value is greater than the threshold (5%, 7%), the driver steps on the accelerator pedal;

[0092] When the vehicle speed is lower than 5 kmph, it is mechanical braking, and when the vehicle speed is higher than 7 kmph, it is motor braking; the threshold (5, 7) is a threshold hysteresis, which means that when the vehicle speed is lower than 5 kmph, the vehicle speed changes to be greater than 7 kmph to exit the mechanical braking and start the motor braking; when the vehicle speed is greater than 7 kmph, the vehicle speed changes to be lower than 5 kmph to exit the motor braking and start the mechanical braking, i.e. between 5-7 kmph, the vehicle always maintains the previous state until the threshold is broken to become the next state;

[0093] The accelerator pedal observation value is a quantity representing the depth of the accelerator pedal stepped on by the driver, generally using a voltage signal or a percentage signal, when the accelerator pedal observation value is less than 5%, it is considered that the accelerator pedal is not stepped on, and when the accelerator pedal observation value is greater than 7%, it is considered that the accelerator pedal is stepped on; the threshold (5%, 7%) is a threshold hysteresis, which means that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to be greater than 7%, it is indicated that the accelerator pedal is stepped on, and when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to be less than 5%, it is indicated that the accelerator pedal is not stepped on, i.e. between 5%-7%, the vehicle always maintains the previous state until the threshold is broken to become the next state.

[0094] When the power steering system enters a long-time working state, the high and low pressure power steering systems assist the driver to steer. The low pressure power steering system is an emergency steering when the high pressure power steering system fails. The intelligent start-stop system can intelligently detect the fault state of the high pressure power steering system, and when the high pressure power steering system fails to work normally due to a fault, the low pressure power steering system is automatically started, and the driver will be prompted to park safely. If both systems fail, the driver will be prompted to park immediately. Unlike the traditional way, when the high pressure power steering system fails, the driver needs to manually start the low pressure power steering system, avoiding safety accidents caused by the driver's nervousness and operational errors.

[0095] The above-described embodiments only express some of the embodiments of the present application, and the description is more specific and detailed, but it should not be understood as limiting the scope of the patent of the present application; it should be pointed out that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application; therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An intelligent control method based on a pure electric mine truck power steering system, characterized in that, The method specifically comprises the following steps: S1, high-voltage power-on of the power-assisted steering system; S2, real-time detection of the intelligent start-stop switch state of the power-assisted steering system by the vehicle VCU, if the driver does not turn on the intelligent start-stop switch of the power-assisted steering system, step S3 is executed; if the driver turns on the intelligent start-stop switch of the power-assisted steering system, step S4 is executed; S3, if the driver does not turn on the intelligent start-stop switch of the power-assisted steering system, the power-assisted steering oil pump works for a long time, and step S2 is repeatedly executed; S4, when the driver turns on the intelligent start-stop switch of the power-assisted steering system, the instrument prompts "steering start-stop switch on", and the power-assisted steering oil pump enters the automatic start-stop system; S5, real-time detection of the vehicle system state by the vehicle VCU, and judgment of whether the steering stop conditions are met at the same time, if the steering stop conditions are met at the same time, step S6 is executed; if the steering stop conditions are not met at the same time, step S7 is executed; S6, when the vehicle system meets the steering stop conditions at the same time, the power-assisted steering system stops, the instrument prompts "steering stop in progress, please press the brake to start", and step S5 is repeatedly executed; S7, when the vehicle system does not meet the steering stop conditions at the same time, the power-assisted steering system enters the long-time working state and step S5 is repeatedly executed.

2. The intelligent control method for the power steering system of the pure electric mine truck according to claim 1, characterized in that: In step S5, the steering stop conditions are specifically: 1) the stop switch is turned on; 2) the vehicle is parked, and the vehicle parking is specifically that the vehicle speed is less than a threshold (0.5, 1) kmph, the threshold (0.5, 1) is a threshold hysteresis, and the accurate meaning is that when the vehicle speed is lower than 0.5 kmph, the vehicle speed changes to be higher than 1 kmph to be considered to exit the parking state; when the vehicle speed is higher than 1 kmph, the vehicle speed changes to be lower than 0.5 kmph to enter the parking state, that is, between 0.5-1 kmph, the vehicle always keeps the last state until the threshold is broken to become the next state; 3) the current gear is in the N gear; 4) the parking system is in the parking; 5) the brake pedal is not pressed, and a brake pedal observation value is less than a threshold (5%, 7%), the threshold (5%, 7%) is a threshold hysteresis, and the accurate meaning is that when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to be greater than 7%, it is indicated that the brake pedal is pressed, when the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to be less than 5%, it is indicated that the brake pedal is not pressed, that is, between 5%-7%, the vehicle always keeps the last state until the threshold is broken to become the next state; 6) the accelerator pedal is not pressed, and an accelerator pedal observation value is less than a threshold (5%, 7%), the threshold (5%, 7%) is a threshold hysteresis, and the accurate meaning is that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to be greater than 7%, it is indicated that the accelerator pedal is pressed; when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to be less than 5%, it is indicated that the accelerator pedal is not pressed, that is, between 5%-7%, the vehicle always keeps the last state until the threshold is broken to become the next state; 7) the steering wheel rotation angle is less than 45 degrees; 8) the steering wheel rotation angular velocity is less than 5 degrees / s.

3. The intelligent control method for the power steering system of the pure electric mine truck according to claim 1, characterized in that: The power steering system comprises a high-pressure power steering system and a low-pressure power steering system, and the power steering system in step S7 enters a long-time working state, specifically: S71, the power steering system receives a working request; S72, the vehicle VCU detects the high-pressure power steering system to determine whether the high-pressure power steering system has a fault, if the high-pressure power steering system has no fault, step S73 is performed; if the high-pressure power steering system has a fault, step S74 is performed; S73, the high-pressure power steering system is started, and step S72 is performed simultaneously; S74, the high-pressure power steering system has a fault, and the instrument prompts "steering fault, please park safely", and the vehicle VCU detects the low-pressure power steering system, if the low-pressure power steering system has no fault, step S75 is performed; if the low-pressure power steering system has a fault, step S76 is performed; S75, the low-pressure power steering system is started, and step S74 is performed, and the vehicle VCU detects the 24V storage battery voltage value, when the voltage value is lower than a threshold value (20, 24) V, a prompt "steering fault, please park immediately" is given, the threshold value (20, 24) is a threshold hysteresis, when the 24V storage battery voltage value is less than 20V, only when the 24V storage battery voltage value changes to be greater than 24V, the 24V storage battery can supply power; when the 24V storage battery voltage value is greater than 24V, only when the 24V storage battery voltage value changes to be less than 20V, the 24V storage battery stops supplying power, that is, between 20 and 24, the vehicle always keeps the previous state until the threshold value is broken to become the next state; S76, the low-pressure power steering system has a fault, and the instrument prompts "steering fault, please park immediately", and the vehicle VCU detects the driver's operation, when the vehicle VCU detects that the driver's operation meets any braking condition, step S77 is performed, when the vehicle VCU detects that the driver's operation does not meet any braking condition, step S76 is continued to be performed; S77, a full braking mode is started.

4. The intelligent control method for the power steering system of the pure electric mine truck according to claim 3, characterized in that: The braking condition in step S76 is specifically: 1) the driver has a braking parking intention, and a brake pedal observation value is greater than a threshold value (5%, 7%), the threshold value (5%, 7%) is a threshold hysteresis, when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to be greater than 7%, it is indicated that the brake pedal is stepped down; when the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to be less than 5%, it is indicated that the brake pedal is not stepped down, that is, between 5% and 7%, the vehicle always keeps the previous state until the threshold value is broken to become the next state; 2) a parking brake (hand brake or electronic EPB) has a braking or parking request; 3) an electric eddy current brake is started by the driver; 4) an energy feedback gear is in the highest gear.

5. The intelligent control method of a power steering system for a pure electric mine truck according to claim 3, characterized in that: The full braking mode in step S77 is specifically: 1) when the vehicle speed is greater than a threshold value (5, 7) kmph, a motor brake is started; 2) compare the motor brake deceleration value and the maximum deceleration value at the current vehicle speed, if the motor brake deceleration value is less than the maximum deceleration value, start the motor brake and apply the mechanical brake in proportion until the maximum deceleration value is reached; 3) when the vehicle speed is lower than the threshold value (5, 7) kmph, start the mechanical brake to park until the driver performs the forward torque output operation, i.e. steps on the accelerator pedal to the accelerator pedal observation value greater than the threshold value (5%, 7%); When the vehicle speed is lower than 5 kmph, it is mechanical brake, and when the vehicle speed is higher than 7 kmph, it is motor brake; the threshold value (5, 7) is a threshold hysteresis, and the accurate meaning is that when the vehicle speed is lower than 5 kmph, the vehicle speed changes to be greater than 7 kmph to exit the mechanical brake and start the motor brake; when the vehicle speed is greater than 7 kmph, the vehicle speed changes to be lower than 5 kmph to exit the motor brake and start the mechanical brake, i.e. between 5-7 kmph, the vehicle always maintains the last state until the threshold value is broken to become the next state.

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