Intelligent control method based on power-assisted steering system of pure electric mining vehicle

Abstract

The invention discloses an intelligent control method based on a power-assisted steering system of a pure electric mining truck, and belongs to the technical field of automobile steering control. The method comprises the following steps: when a driver turns on an intelligent start-stop switch of a power-assisted steering system, entering an automatic start-stop system of a power-assisted steering oil pump; the whole vehicle VCU detects the state of the whole vehicle system in real time and judges whether the steering stop condition is met at the same time or not; when the steering shutdown condition is met at the same time, the power-assisted steering system is shut down; and when the simultaneous steering shutdown condition is not met, the power-assisted steering system enters a long-time working state. The requirement of a driver for steering can be intelligently judged, starting and stopping of the steering system are intelligently controlled, and energy consumption is reduced; when the vehicle is parked and waits, the system is stopped, and noise of a cab is reduced; if the high-pressure power-assisted steering system and the low-pressure power-assisted steering system fail simultaneously, immediate parking When high-pressure steering fails, low-pressure power-assisted steering can be automatically started, and compared with a traditional mode that a low-pressure power-assisted steering system needs to be manually started, operation errors are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of automobile steering control, and in particular is an intelligent control method based on a power steering system of a pure electric mining vehicle. Background Art

[0002] The electrification of construction machinery is an important part of achieving the national dual-carbon strategy. Pure electric mining trucks have huge environmental and economic advantages over fuel mining trucks. Due to the heavy load of mining trucks, the steering operation cannot be completed by relying solely on the driver's strength. The power steering system provides additional assistance for the driver to operate the steering of the mining truck. Therefore, the power steering system plays an important role in the safe operation of mining trucks.

[0003] The existing mining truck steering system is a hydraulic steering system. Fuel mining trucks use the engine to drive the oil pump to provide steering assistance, and pure electric mining trucks use high-voltage batteries + motors to drive high-pressure oil pumps to provide steering assistance. When the vehicle is in high-pressure state (normal driving or temporary parking), the high-pressure power pump is always working, causing energy waste; when the vehicle is parked, the high-pressure oil pump generates noise pollution, which endangers the driver's health; after the high-pressure steering system fails, the driver needs to manually start the emergency steering system, which is prone to operating errors and poses safety hazards. Summary of the invention

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

[0005] The purpose of the present invention is to solve the problem that the existing high-pressure oil pump of a mining truck works ineffectively, causing energy waste and noise pollution, and secondly, to solve the problem that after the existing high-pressure system fails, the driver needs to manually operate the emergency steering system.

[0006] 2. Technical solution

[0007] In order to achieve the above object, the technical solution provided by the present invention is:

[0008] The present invention provides an intelligent control method based on a power steering system of a pure electric mining vehicle, the method specifically comprising the following steps:

[0009] S1, high voltage power on for power steering system;

[0010] S2, the vehicle VCU detects the status 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, execute step S3; if the driver turns on the power steering system intelligent start-stop switch, execute step S4;

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

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

[0013] S5, the vehicle VCU detects the vehicle system status in real time and determines whether the steering stop conditions are met at the same time. If the steering stop conditions are met at the same time, execute step S6; if the steering stop conditions are not met at the same time, execute step S7;

[0014] S6. When the vehicle VCU detects that the vehicle system meets the steering shutdown condition at the same time, the power steering system is shut down, the instrument prompts "Steering shutdown, please step on the brake to start", and repeats step S5;

[0015] S7. When the vehicle VCU detects that the vehicle system does not meet the simultaneous steering shutdown condition, the power steering system enters a long-term working state and repeats step S5.

[0016] Preferably, in step S5, the steering stop condition is specifically:

[0017] 1) The shutdown switch is turned on;

[0018] 2) Vehicle parking. Specifically, the vehicle parking means that the vehicle speed is less than a threshold value (0.5, 1) Kmph. The threshold value (0.5, 1) is a threshold hysteresis loop. The exact meaning is that when the vehicle speed is less than 0.5 Kmph, the vehicle speed must change to more than 1 Kmph to exit the parking state; when the vehicle speed is more than 1 Kmph, the vehicle speed must change to less than 0.5 Kmph to enter the parking state. That is, between 0.5 and 1 Kmph, the vehicle keeps the previous state until it breaks through the threshold to change to the next state;

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

[0020] 4) The parking system is in parking mode;

[0021] 5) The brake pedal is not pressed, and the brake pedal observation value is less than the threshold value (5%, 7%). The threshold value (5%, 7%) is the threshold hysteresis loop. The exact meaning is that when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to more than 7%, it indicates that the brake pedal has been pressed. When the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to less than 5%, it indicates that the brake pedal is not pressed. That is, between 5% and 7%, the vehicle keeps the previous state until it breaks through the threshold to change to the next state;

[0022] 6) The accelerator pedal is not depressed, and the accelerator pedal observation value is less than the threshold value (5%, 7%). The threshold value (5%, 7%) is a threshold hysteresis loop, which means that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to more than 7%, it indicates that the accelerator pedal has been depressed; when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to less than 5%, it indicates that the accelerator pedal is not depressed, that is, between 5% and 7%, the vehicle keeps the previous state until it breaks through the threshold to change to 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-term working state, specifically:

[0026] S71, the power steering system receives a work 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 does not have a fault, execute step S73; if the high-pressure power steering system has a fault, execute step S74;

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

[0029] S74: If the high-pressure power steering system fails, the instrument prompts "Steering failure, please stop safely", and the vehicle VCU detects the low-pressure power steering system. If the low-pressure power steering system does not fail, execute step S75; if the low-pressure power steering system fails, execute step S76;

[0030] S75, the low-voltage power steering system is started, and step S74 is executed. At the same time, the vehicle VCU detects the 24V battery voltage value. When the voltage value is lower than the threshold value (20, 24), it prompts "steering fault, please stop immediately". The threshold value (20, 24) is a threshold hysteresis loop. When the 24V battery voltage value is less than 20V, the 24V battery can only supply power when the 24V battery voltage value changes to greater than 24V; when the 24V battery voltage value is greater than 24V, the 24V battery stops supplying power only when the 24V battery voltage value changes to less than 20V, that is, between 20 and 24, the vehicle keeps the previous state until the threshold value is broken to change to the next state;

[0031] S76: The low-pressure power steering system has a fault, and the instrument prompts "Steering fault, please stop immediately". At the same time, 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, turn on full braking mode.

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

[0034] 1) The driver intends to stop the vehicle by braking, and the observed value of the brake pedal is greater than the threshold value (5%, 7%). The threshold value (5%, 7%) is a threshold hysteresis loop. When the observed value of the brake pedal is less than 5%, it indicates that the brake pedal has been pressed only when the observed value of the brake pedal changes to greater than 7%. When the observed value of the brake pedal is greater than 7%, it indicates that the brake pedal has not been pressed only when the observed value of the brake pedal changes to less than 5%. That is, between 5% and 7%, the vehicle keeps the previous state until it breaks through the threshold value to change to the next state.

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

[0036] 3) The eddy current retarder is turned on by the driver;

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

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

[0039] 1) When the vehicle speed is greater than the threshold (5, 7) Kmph, the motor brake is activated;

[0040] 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 mechanical braking in proportion until the maximum deceleration value is reached;

[0041] 3) When the vehicle speed is lower than the threshold (5, 7) Kmph, the mechanical brake is activated to park the vehicle until the driver performs a forward torque output operation, that is, depresses the accelerator pedal until the accelerator pedal observation value is greater than the threshold (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 value (5, 7) is a threshold hysteresis loop, which accurately means that when the vehicle speed is lower than 5Kmph, the vehicle speed must change to greater than 7Kmph to exit from mechanical braking and start motor braking; when the vehicle speed is higher than 7Kmph, the vehicle speed must change to less than 5Kmph to exit from motor braking and start mechanical braking, that is, between 5 and 7Kmph, the vehicle maintains the previous state until it breaks through the threshold to change to the next state.

[0043] 3. Beneficial effects

[0044] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0045] The present invention discloses an intelligent control method based on a power steering system for a pure electric mining vehicle. The method includes: when the driver turns on the intelligent start-stop switch of the power steering system, the power steering oil pump automatic start-stop system is entered; the vehicle VCU detects the vehicle system status in real time and determines whether the steering shutdown conditions are met at the same time; when the steering shutdown conditions are met at the same time, the power steering system is shut down; when the simultaneous steering shutdown conditions are not met, the power steering system enters a long-term working state. The present invention can intelligently determine the driver's demand for steering, intelligently control the start and stop of the steering system, and reduce energy consumption; when waiting for parking, the system is shut down to reduce the noise in the cab; when the high and low pressure power steering systems fail at the same time, it will prompt to stop immediately. When the high pressure steering fails, the low pressure power steering will be automatically started, and it is no longer like the traditional way, which requires manual start of the low pressure power steering system to avoid operating errors. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Figure 1 It is a flow chart of an intelligent control method based on a power steering system of a pure electric mining vehicle of the present invention;

[0047] Figure 2 The power steering system enters a long-term working process diagram in step S7 of the present invention;

[0048] Figure 3 It is a schematic structural diagram of the power steering system of the present invention. DETAILED DESCRIPTION

[0049] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present application.

[0050] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present application described here. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes 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.

[0051] In this application, the terms "upper", "lower", "left", "right", "front", "back", "top", "bottom", "inside", "outside", "center", "vertical", "horizontal", "lateral", "longitudinal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used 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, some of the above terms may be used to express other meanings in addition to indicating orientation or positional relationship. For example, the term "on" may also be used to express a certain dependency or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in this application can be understood according to specific circumstances.

[0053] In addition, the terms "installed", "set", "provided with", "connected", "connected", and "socketed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection, or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be an internal connection between two devices, elements, or components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0054] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0055] Example 1

[0056] See attached Figure 1-3, the present embodiment is an intelligent control method based on a power steering system of a pure electric mining vehicle. The power steering system adopted in the method is used to provide additional power for the driver to operate the steering of the mining vehicle, so that the driver can simplify the operation during the steering operation of the mining vehicle. 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, which supplies power to the high-voltage steering motor through a 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 battery, which directly supplies power to the low-voltage steering motor. The low-voltage steering motor drives a low-pressure oil pump to provide hydraulic oil for the steering system to support steering work. In the high-voltage state, the high-voltage power supply supplies power to the vehicle-mounted low-voltage battery through a DCDC converter, and at the same time provides energy for the low-voltage power steering system; in the low-voltage state, the energy is directly provided by the vehicle-mounted low-voltage battery. The power steering system contains an intelligent start-stop function, which is used to intelligently assist the power steering system and reduce the driver's operating steps. The intelligent start-stop function can only be enabled under high pressure; the power steering oil pump is a high-pressure oil pump in a high-pressure power steering system and a low-pressure oil pump in a low-pressure power steering system.

[0057] The method specifically comprises the following steps:

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

[0059] S2, the vehicle VCU detects the status 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, execute step S3; if the driver turns on the power steering system intelligent start-stop switch, execute step S4;

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

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

[0062] S5, the vehicle VCU detects the vehicle system status in real time and determines whether the steering stop conditions are met at the same time. If the steering stop conditions are met at the same time, execute step S6; if the steering stop conditions are not met at the same time, execute step S7;

[0063] S6. When the vehicle VCU detects that the vehicle system meets the steering shutdown condition at the same time, the power steering system is shut down, and the instrument prompts "Steering is shut down, please step on the brake to start", and repeats step S5. At this time, the power steering system is shut down, which reduces energy loss and noise. The driver sitting in the cab will not be disturbed by noise, which improves driving comfort;

[0064] S7. When the vehicle VCU detects that the vehicle system does not meet the simultaneous steering shutdown condition, the power steering system enters a long-term working state and repeats step S5.

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

[0066] 1) The shutdown switch is turned on;

[0067] 2) Vehicle parking. Specifically, vehicle parking means that the vehicle speed is less than a threshold value (0.5, 1) Kmph. When the vehicle speed is less than 0.5 Kmph, it is in the parking state. When the vehicle speed is higher than 1 Kmph, it exits the parking state. The threshold value (0.5, 1) is the threshold hysteresis loop. Setting the threshold hysteresis loop can effectively avoid parking state fluctuations caused by vehicle speed jitter. At the same time, when the vehicle speed is lower than 0.5 Kmph, the vehicle is almost in a motionless state, and EPB can park smoothly. The threshold hysteresis loop is generally divided into two directions, changing from small to large, or from large to small. The exact meaning is that when the vehicle speed is lower than 0.5 Kmph, the vehicle speed changes to 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 lower than 0.5 Kmph to enter the parking state. That is, between 0.5 and 1 Kmph, the vehicle keeps the previous state until it breaks through the threshold to change to the next state.

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

[0069] 4) The parking system is in parking mode;

[0070] 5) The brake pedal is not stepped on, and the brake pedal observation value is less than (5%, 7%). The brake pedal observation value is a quantity that characterizes the depth of the driver's stepping on the brake pedal. 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. 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 loop. Setting the threshold value (5%, 7%) can effectively avoid parking state fluctuations caused by vehicle speed jitter. The exact meaning is that when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to greater than 7%, it indicates that the brake pedal has been stepped on. When the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to less than 5%, it indicates that the brake pedal is not stepped on. That is, between 5% and 7%, the vehicle always maintains the previous state until it breaks through the threshold to change to the next state.

[0071] 6) The accelerator pedal is not depressed, and the accelerator pedal observation value is less than (5%, 7%). The accelerator pedal observation value is a quantity that characterizes the depth of the driver's depression of the accelerator pedal. Generally, a voltage signal or a percentage signal is used. When the accelerator pedal observation value is less than 5%, it is considered that the accelerator pedal is not depressed. When the accelerator pedal observation value is greater than 7%, it is considered that the accelerator pedal is depressed. The threshold value (5%, 7%) is a threshold hysteresis loop. The exact meaning is that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to greater than 7%, it indicates that the accelerator pedal has been depressed. When the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to less than 5%, it indicates that the accelerator pedal is not depressed. That is, between 5% and 7%, the vehicle maintains the previous state until the threshold is broken to change to the next state.

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

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

[0074] When the vehicle VCU detects that all the above-mentioned shutdown conditions are met, the vehicle VCU sends a shutdown signal to the power steering system. The power steering system shuts down after receiving the signal, thereby 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-term working state, specifically:

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

[0077] 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 does not have a fault, execute step S73; if the high-pressure power steering system has a fault, execute step S74;

[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: If the high-pressure power steering system fails, the instrument prompts "Steering failure, please stop safely", and the vehicle VCU detects the low-pressure power steering system. If the low-pressure power steering system does not fail, execute step S75; if the low-pressure power steering system fails, execute step S76;

[0080] S75, the low-voltage power steering system is started to assist the driver in steering operations, and step S74 is executed. At the same time, the vehicle VCU detects the voltage value of the 24V battery. The 24V battery is a vehicle-mounted low-voltage battery that supplies power to the low-voltage power steering system. When the voltage value is lower than the threshold value (20, 24), the low-voltage power steering system cannot work, and a prompt "steering failure, please stop immediately" is displayed. When the voltage value is lower than the threshold value, step S76 is executed; when the voltage value is not lower than the threshold value, step S74 is continued to be executed; the threshold value (20, 24) is a threshold hysteresis loop. When the 24V battery voltage value is less than 20V, the 24V battery can only supply power when the 24V battery voltage value changes to greater than 24V; when the 24V battery voltage value is greater than 24V, the 24V battery stops supplying power only when the 24V battery voltage value changes to less than 20V, that is, between 20 and 24, the vehicle always maintains the previous state until the threshold value is broken to change to the next state;

[0081] S76, the low-pressure power steering system has a fault, and the instrument prompts "Steering fault, please stop safely". At this time, the power steering system has a fault and cannot be used. When the driver encounters an emergency, it is necessary to turn on the full braking mode. 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.

[0082] S77, full braking mode is activated.

[0083] The braking conditions in step S76 are specifically:

[0084] 1) The driver intends to stop the vehicle by braking, and the brake pedal observation value is greater than (5%, 7%). The brake pedal observation value is a quantity that characterizes the depth of the driver's braking pedal. 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. 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 loop. When the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to greater than 7%, it indicates that the brake pedal has been stepped on. When the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to less than 5%, it indicates that the brake pedal is not stepped on. That is, between 5% and 7%, the vehicle maintains the previous state until the threshold is broken to change to the next state.

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

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

[0087] 4) The energy feedback gear is at the highest gear.

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

[0089] 1) When the vehicle speed is greater than the threshold value (5, 7) Kmph, the motor braking is started. The motor braking is specifically to apply a torque opposite to the rotation direction on the motor rotating shaft to quickly decelerate or stop the system, that is, to use 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 mechanical braking in proportion until the maximum deceleration value is reached. The mechanical braking mainly uses the electric mining vehicle brake device to slow down or stop.

[0091] 3) When the vehicle speed is less than a threshold value (5, 7) Kmph, the mechanical brake is activated to park the vehicle until the driver performs a forward torque output operation, wherein the driver performs a forward torque output operation by pressing the accelerator pedal. When the accelerator pedal observation value is greater than a threshold value (5%, 7%), the driver presses the accelerator pedal;

[0092] When the vehicle speed is lower than 5Kmph, it is mechanical braking, and when the vehicle speed is higher than 7Kmph, it is motor braking; the threshold (5, 7) is a threshold hysteresis loop, which means that when the vehicle speed is lower than 5Kmph, the vehicle speed must change to more than 7Kmph before the mechanical braking can be exited and the motor braking can be started; when the vehicle speed is higher than 7Kmph, the vehicle speed must change to less than 5Kmph before the motor braking can be exited and the mechanical braking can be started, that is, between 5 and 7Kmph, the vehicle keeps the previous state until it breaks through the threshold to change to the next state;

[0093] The accelerator pedal observation value is a quantity that characterizes the depth of the driver's depression of the accelerator pedal, and generally uses 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 depressed, and when the accelerator pedal observation value is greater than 7%, it is considered that the accelerator pedal is depressed; the threshold value (5%, 7%) is a threshold hysteresis loop, and its exact meaning is that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to greater than 7%, it indicates that the accelerator pedal is depressed, and when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to less than 5%, it indicates that the accelerator pedal is not depressed, that is, between 5% and 7%, the vehicle always maintains the previous state until it breaks through the threshold to change to the next state.

[0094] When the power steering system enters a long-term working state, the high and low pressure power steering systems assist the driver in steering. 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. When the high pressure power steering system fails to work normally due to a fault, the low pressure power steering system will be automatically started, and the driver will be prompted to stop safely. If both systems fail at the same time, the driver will be prompted to stop immediately. Unlike the traditional method, when the high pressure power steering system fails, the driver needs to manually start the low pressure power steering system to avoid safety accidents caused by the driver's nervousness and operating errors.

[0095] The above-described embodiments only express a certain implementation mode of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the patent scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. An intelligent control method based on the power steering system of a pure electric mining vehicle. It is characterized in that The method specifically comprises the following steps: S1, high voltage power on for power steering system; S2, the vehicle VCU detects the status 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, execute step S3; if the driver turns on the power steering system intelligent start-stop switch, execute step S4; S3, if the driver does not turn on the intelligent start-stop switch of the power steering system, the power steering oil pump works for a long time, and step S2 is repeated; S4. When the driver turns on the intelligent start-stop switch of the power steering system, the instrument prompts "Steering start-stop on", and the power steering oil pump automatic start-stop system is entered; S5, the vehicle VCU detects the vehicle system status in real time and determines whether the steering stop conditions are met at the same time. If the steering stop conditions are met at the same time, execute step S6; if the steering stop conditions are not met at the same time, execute step S7; S6. When the vehicle VCU detects that the vehicle system meets the steering shutdown conditions at the same time, the power steering system is shut down, the instrument prompts "Steering shutdown, please step on the brake to start", and repeats step S5; S7. When the vehicle VCU detects that the vehicle system does not meet the simultaneous steering shutdown condition, the power steering system enters a long-term working state and repeats step S5.

2. According to claim 1, an intelligent control method based on a power steering system for a pure electric mining vehicle, Features: In step S5, the steering stop condition is specifically: 1) The shutdown switch is turned on; 2) Vehicle parking. Specifically, the vehicle parking means that the vehicle speed is less than a threshold value (0.5, 1) Kmph. The threshold value (0.5, 1) is a threshold hysteresis loop. The exact meaning is that when the vehicle speed is less than 0.5 Kmph, the vehicle speed must change to more than 1 Kmph to exit the parking state; when the vehicle speed is more than 1 Kmph, the vehicle speed must change to less than 0.5 Kmph to enter the parking state. That is, between 0.5 and 1 Kmph, the vehicle keeps the previous state until it breaks through the threshold to change to the next state; 3) The current gear is in N gear; 4) The parking system is in parking mode; 5) The brake pedal is not pressed, and the brake pedal observation value is less than the threshold value (5%, 7%). The threshold value (5%, 7%) is the threshold hysteresis loop. The exact meaning is that when the brake pedal observation value is less than 5%, only when the brake pedal observation value changes to more than 7%, it indicates that the brake pedal has been pressed. When the brake pedal observation value is greater than 7%, only when the brake pedal observation value changes to less than 5%, it indicates that the brake pedal is not pressed. That is, between 5% and 7%, the vehicle keeps the previous state until it breaks through the threshold to change to the next state; 6) The accelerator pedal is not depressed, and the accelerator pedal observation value is less than the threshold value (5%, 7%). The threshold value (5%, 7%) is a threshold hysteresis loop, which means that when the accelerator pedal observation value is less than 5%, only when the accelerator pedal observation value changes to more than 7%, it indicates that the accelerator pedal has been depressed; when the accelerator pedal observation value is greater than 7%, only when the accelerator pedal observation value changes to less than 5%, it indicates that the accelerator pedal is not depressed, that is, between 5% and 7%, the vehicle keeps the previous state until it breaks through the threshold to change to 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. According to claim 1, an intelligent control method based on a power steering system for a pure electric mining vehicle, Features: The power steering system comprises a high-pressure power steering system and a low-pressure power steering system. The power steering system in step S7 enters a long-time working state, specifically: S71, the power steering system receives a work 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 does not have a fault, execute step S73; if the high-pressure power steering system has a fault, execute step S74; S73, the high-pressure power steering system is started, and step S72 is executed at the same time; S74: The high-pressure power steering system has a fault, and the instrument prompts "Steering fault, please stop safely". At the same time, the vehicle VCU detects the low-pressure power steering system. If the low-pressure power steering system does not have a fault, execute step S75; if the low-pressure power steering system has a fault, execute step S76; S75, the low-voltage power steering system is started, and step S74 is executed. At the same time, the vehicle VCU detects the 24V battery voltage value. When the voltage value is lower than the threshold value (20, 24)V, it prompts "steering fault, please stop immediately". The threshold value (20, 24) is a threshold hysteresis loop. When the 24V battery voltage value is less than 20V, the 24V battery can only supply power when the 24V battery voltage value changes to greater than 24V; when the 24V battery voltage value is greater than 24V, the 24V battery stops supplying power only when the 24V battery voltage value changes to less than 20V, that is, between 20 and 24, the vehicle keeps the previous state until the threshold value is broken to change to the next state; S76: The low-pressure power steering system has a fault, and the instrument prompts "Steering fault, please stop immediately". At the same time, 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. S77, turn on full braking mode.

4. According to claim 3, an intelligent control method based on a power steering system for a pure electric mining vehicle, Features: The braking conditions in step S76 are specifically: 1) The driver intends to stop the vehicle by braking, and the observed value of the brake pedal is greater than the threshold value (5%, 7%). The threshold value (5%, 7%) is a threshold hysteresis loop. When the observed value of the brake pedal is less than 5%, it indicates that the brake pedal has been pressed only when the observed value of the brake pedal changes to greater than 7%. When the observed value of the brake pedal is greater than 7%, it indicates that the brake pedal has not been pressed only when the observed value of the brake pedal changes to less than 5%. That is, between 5% and 7%, the vehicle keeps the previous state until it breaks through the threshold value to change to the next state. 2) The parking brake (handbrake or electronic EPB) has a braking or parking request; 3) The eddy current retarder is turned on by the driver; 4) The energy feedback gear is at the highest gear.

5. According to claim 3, an intelligent control method based on a power steering system for a pure electric mining vehicle, Features: The full braking mode in step S77 is specifically: 1) When the vehicle speed is greater than the threshold (5, 7) Kmph, the motor brake is activated; 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 mechanical braking in proportion until the maximum deceleration value is reached; 3) When the vehicle speed is lower than the threshold (5, 7) Kmph, the mechanical brake is activated to park the vehicle until the driver performs a forward torque output operation, that is, depresses the accelerator pedal until the accelerator pedal observation value is greater than the threshold (5%, 7%); 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 value (5, 7) is a threshold hysteresis loop, which accurately means that when the vehicle speed is lower than 5Kmph, the vehicle speed must change to greater than 7Kmph to exit from mechanical braking and start motor braking; when the vehicle speed is higher than 7Kmph, the vehicle speed must change to less than 5Kmph to exit from motor braking and start mechanical braking, that is, between 5 and 7Kmph, the vehicle maintains the previous state until it breaks through the threshold to change to the next state.

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