Electric brake control system and method for electrically-driven mining dump truck

Abstract

The invention discloses an electric brake control system and method for an electrically-driven mining dump truck, and the system comprises a vehicle control unit VCU which is connected with an accelerator pedal, a brake pedal, a tilt angle sensor, a weighing sensor, an intelligent brake switch, a motor controller, a power battery and a retarder. The vehicle control unit VCU, the motor controller and the power battery sequentially form a closed loop, and the motor controller is further sequentially connected with the driving motor, the gearbox and the axle. Whether a vehicle is in a downhill state or not at present is analyzed through the vehicle control unit VCU, the slope angle and the vehicle weight are converted, the vehicle speed, the friction coefficient and the like are combined, appropriate electric braking torque of the vehicle is converted to keep the vehicle speed lower than a certain speed for downhill, and a driving motor is preferentially used for generating electricity and feeding back the electricity to a power battery to achieve braking. When the power generation braking force is insufficient, the retarder intervenes to supplement the braking torque, so that the electrically-driven mine truck automatically goes downhill at a stable speed, energy recovery is realized to the greatest extent, the cruising ability of the electrically-driven mine truck is improved, the electric quantity configuration of a power battery is reduced, and the effects of saving energy, reducing emission and reducing cost are achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of electric-driven mining vehicles, and in particular to an electric brake control system and method for an electric-driven mining dump truck. Background Art

[0002] Conventional mining dump trucks use engines as power sources. Mining dump trucks consume a lot of energy and need to consume a lot of fuel. In recent years, electric-driven mining trucks have been booming and have been used in many mines, but mining trucks have complex operating conditions and many slopes. Existing electric mining trucks are only equipped with accelerator pedals and brake pedals. A few electric mining trucks are equipped with manually controlled retarders, that is, the driver turns on the retarder and the retarder gear setting as needed. Especially when going down a long slope, driving such a heavy vehicle requires a lot of physical and mental energy from the driver, and the driver needs to keep stepping on the brake pedal. The vehicle speed stability is not easy to control, especially when going down a long slope, and the driver is tired from stepping on the brake pedal for a long time.

[0003] In addition, mining vehicles consume huge amounts of energy during operation and need to be equipped with power batteries with large capacities. The cost of the entire vehicle is high and it is difficult to promote it. Therefore, it is necessary to increase the braking energy recovery rate. In particular, it is necessary to study intelligent and efficient energy recovery technology when going down long slopes, increase the endurance of electric-driven mining vehicles, and achieve energy conservation and emission reduction. Summary of the invention

[0004] The purpose of the present invention is to provide an electric brake control system and method for an electric-driven mining dump truck, which is used to solve the technical problems in the prior art that existing mining vehicles equipped with fuel engines have high emissions, serious pollution, lack of brake energy recovery function, poor driving stability and comfort for drivers when going down long slopes, etc.

[0005] The present invention solves the above problems through the following technical solutions:

[0006] An electric brake control system for an electric-driven mining dump truck comprises: a vehicle controller VCU, an accelerator pedal, a brake pedal, an inclination sensor, an intelligent brake switch, a motor controller, a power battery, a retarder, a drive motor, a weighing sensor, a gearbox and an axle; the vehicle controller VCU is respectively connected to the accelerator pedal, the brake pedal, the inclination sensor, the weighing sensor, the intelligent brake switch, the motor controller, the power battery and the retarder, and the vehicle controller VCU, the motor controller and the power battery sequentially form a closed loop, and the motor controller is also sequentially connected to the drive motor, the gearbox and the axle;

[0007] The vehicle controller VCU is responsible for collecting the position information of the two pedals, the control signals of various sensors and switches, analyzing the driver's control intention, and sending control instructions to the motor controller to drive the vehicle or recover braking energy based on the vehicle speed, vehicle posture and power battery status; and sending control instructions to the retarder to supplement the braking torque;

[0008] The accelerator pedal is the input interface for the driver to control the vehicle's driving torque, and the brake pedal is the input interface for the driver to control the vehicle's braking torque;

[0009] The inclination sensor is used to detect the slope angle and positive and negative directions of the slope where the vehicle is located. The vehicle controller VCU can collect the inclination sensor signal and calculate the vehicle posture;

[0010] The weighing sensor is used to detect the weight of the vehicle load. The vehicle controller VCU can collect the weighing sensor signal and calculate the weight of the vehicle.

[0011] The motor controller is used to control the operation of the drive motor; the power battery provides energy for the vehicle; the retarder is used to assist braking; the gearbox and the axle transmit the power of the drive motor, thereby driving the vehicle;

[0012] The electric brake control system of the electric-driven mining dump truck has a driver control mode and an intelligent brake mode with driver control priority when going downhill, and the intelligent brake switch is used for switching the modes.

[0013] At the same time, the present invention also solves the above problems through the following technical solutions:

[0014] A method for controlling electric brake of an electric-driven mining dump truck is implemented by the electric brake control system of the electric-driven mining dump truck as described above.

[0015] As a further improvement of the present invention, the control method comprises:

[0016] When the smart brake switch is off and the vehicle is in driver control mode when going downhill;

[0017] The driver controls the vehicle speed by stepping on the brake pedal according to the vehicle speed. The vehicle controller VCU receives the brake pedal depression depth signal, and based on the vehicle speed and the status of the power battery, sends a negative torque command opposite to the motor direction to the motor controller. The motor controller controls the drive motor to generate negative torque to resist rotation. At this time, the drive motor is in power generation mode to charge the power battery.

[0018] As a further improvement of the present invention, the control method comprises:

[0019] When the smart brake switch is on and the vehicle is downhill, it is in smart brake mode;

[0020] The vehicle controller VCU collects information from the inclination sensor to calculate the slope angle of the slope on which the vehicle is located. The vehicle controller VCU collects information from the weighing sensor and calculates the current total vehicle mass in combination with the basic parameters of the vehicle. The vehicle controller VCU uses the automobile power calculation formula to calculate the electric braking torque required to maintain the current vehicle speed downhill, and performs PID adjustment of the electric braking torque according to the target vehicle speed, and sends the electric braking torque command to the motor controller. The motor controller controls the drive motor to generate negative torque to resist rotation. At this time, the drive motor is in power generation mode to charge the power battery.

[0021] As a further improvement of the present invention, the control method further includes:

[0022] When the vehicle is in intelligent braking mode, when the allowable charging power of the power battery is small, and the electric braking torque generated by the motor controller is less than the actual required braking torque, the vehicle controller VCU calculates the insufficient braking torque according to the allowable charging power of the power battery, and sends the insufficient braking torque command to the retarder, and the retarder generates braking torque to make up for the insufficient braking torque.

[0023] As a further improvement of the present invention, the slope angle calculation formula of the ramp where the vehicle is located is:

[0024]

[0025] Where: α is the slope angle of the current vehicle driving section;

[0026] A is the current digital value of the inclination sensor detected by the vehicle controller VCU;

[0027] B is the digital value calibrated when the tilt sensor is at zero angle;

[0028] C is the digital value of the inclination sensor when it is tilted 90°.

[0029] When the α angle value is positive, the vehicle is in a climbing state; when the α angle value is negative, the vehicle is in a downhill state.

[0030] As a further improvement of the present invention, the electric braking torque calculation formula required to maintain the current vehicle speed downhill is:

[0031]

[0032] Where: T is the current required electric braking torque;

[0033] m is the current total vehicle weight;

[0034] g is the value of gravitational acceleration;

[0035] α is the slope angle of the current vehicle driving section;

[0036] f is the friction coefficient of the road surface in the current road section where the vehicle is located;

[0037] C D is the vehicle drag coefficient;

[0038] A is the frontal area of ​​the vehicle;

[0039] u i is the target vehicle speed to be controlled;

[0040] r is the radius of the vehicle tire;

[0041] i g i0 is the total reduction ratio from the vehicle drive motor to the wheel drive shaft end;

[0042] η T For mechanical transmission efficiency.

[0043] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0044] The present invention collects information of the inclination sensor installed on the vehicle body through the vehicle controller VCU, analyzes whether the vehicle is currently in a downhill state, and converts the slope angle; the vehicle controller VCU converts the weight of the whole vehicle by collecting the weighing sensor information, combines the vehicle speed, friction coefficient, etc., and converts the appropriate electric braking torque of the vehicle through the automobile power calculation formula to keep the vehicle speed below a certain speed when going downhill, and preferentially uses the drive motor to generate electricity and feed back to the power battery to achieve braking. When the driving motor generates insufficient braking force, the retarder intervenes to supplement the corresponding braking torque, and finally achieves automatic steady speed downhill of the electric-driven mining vehicle, and maximizes energy recovery, increases the endurance of the electric-driven mining vehicle, reduces the power battery configuration, and achieves the effect of energy saving, emission reduction and cost reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 The present invention is a block diagram of an electric brake control system for an electric-driven mining dump truck. DETAILED DESCRIPTION

[0046] In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions in the embodiments of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0047] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0048] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0049] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display that includes a series of steps or elements is not necessarily limited to those steps or elements explicitly listed but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0051] The following will be combined Figure 1 , an electric brake control system and method for an electric-driven mining dump truck involved in the embodiments of the present application are described in detail. It is worth noting that the following embodiments are only used to explain the present application and do not constitute a limitation on the present application.

[0052] Example

[0053] Combined with Figure 1As shown, an electric brake control system for an electric-driven mining dump truck includes: a vehicle controller VCU, an accelerator pedal, a brake pedal, an inclination sensor, an intelligent brake switch, a motor controller, a power battery, a retarder, a drive motor, a weighing sensor, a gearbox and axle, etc.; the vehicle controller VCU is respectively connected to the accelerator pedal, the brake pedal, the inclination sensor, the weighing sensor, the intelligent brake switch, the motor controller, the power battery and the retarder, and the vehicle controller VCU, the motor controller and the power battery form a closed loop in sequence, and the motor controller is also connected to the drive motor, the gearbox and the axle in sequence. The vehicle controller VCU is the center of the control system. The vehicle controller VCU is responsible for collecting the position information of the two pedals, the inclination sensor and the weighing sensor information, etc., analyzing and identifying the driver's control intention and the posture of the vehicle, and combining the power battery SOC state to control the drive motor and the retarder to drive or brake the vehicle. When going downhill, it can automatically and intelligently control the vehicle speed and recover the braking energy to the power battery.

[0054] Among them, the vehicle controller VCU is the core of the entire control system. It is responsible for collecting control signals from various sensors and switches, analyzing the driver's control intentions, and sending control instructions to the motor controller to drive the vehicle or recover braking energy based on the vehicle speed, vehicle posture and power battery status; sending control instructions to the retarder to supplement the braking torque.

[0055] The accelerator pedal is the input interface for the driver to control the vehicle's driving torque, and the brake pedal is the input interface for the driver to control the vehicle's braking torque.

[0056] The inclination sensor is used to detect the slope angle and positive and negative directions of the slope on which the vehicle is located. The vehicle controller VCU can collect the inclination sensor signal and calculate the vehicle posture.

[0057] The electric brake control system of the electric-driven mining dump truck provided in the present application has a driver control mode and an intelligent braking mode with driver control priority when going downhill, and the intelligent brake switch is used to switch between the two modes.

[0058] The weighing sensor is used to detect the weight of the mining vehicle. The vehicle controller VCU can collect the weighing sensor signal and calculate the weight of the vehicle.

[0059] The motor controller is used to control the operation of the drive motor; the power battery provides energy for the entire vehicle; the retarder is used to assist braking; the gearbox and axle transmit the power of the drive motor, thereby driving the entire vehicle.

[0060] In an optional embodiment, an electric brake control method for an electric-driven mining dump truck is implemented by an electric brake control system for an electric-driven mining dump truck.

[0061] Specific methods include:

[0062] When the smart brake switch is in the off state and the vehicle is driving downhill, the vehicle driver controls the mode;

[0063] The driver controls the vehicle speed by stepping on the brake pedal according to the vehicle speed. The vehicle controller VCU receives the brake pedal stepping depth signal, and based on the vehicle speed and the status of the power battery, sends a negative torque command opposite to the motor direction to the motor controller. The motor controller controls the drive motor to generate negative torque to resist rotation. At this time, the drive motor is in the power generation mode to charge the power battery. In addition to the electrical braking torque, stepping on the brake pedal also generates a mechanical braking torque. This part of the braking energy cannot be recovered.

[0064] When the smart brake switch is on and the vehicle is downhill, it is in smart brake mode;

[0065] The vehicle controller VCU collects information from the inclination sensor to calculate the slope angle of the slope on which the vehicle is located. The vehicle controller VCU collects information from the weighing sensor and calculates the current total vehicle mass in combination with the basic parameters of the vehicle. The vehicle controller VCU uses the automobile power calculation formula to calculate the electric braking torque required to maintain the current vehicle speed downhill, and performs PID adjustment of the electric braking torque according to the target vehicle speed, and sends the electric braking torque command to the motor controller. The motor controller controls the drive motor to generate negative torque to resist rotation. At this time, the drive motor is in power generation mode to charge the power battery.

[0066] Preferably, when the vehicle is in the intelligent braking mode, when the power battery allows a small charging power, and the electric braking torque generated by the motor controller is less than the actual required braking torque, the vehicle controller VCU calculates the insufficient braking torque according to the power battery's allowed charging power, and sends the braking torque command to the retarder, and the retarder generates a braking torque to make up for the insufficient braking torque;

[0067] In this working mode, the driver does not need to step on the brake pedal to achieve vehicle deceleration or constant speed downhill, and can maximize the recovery of vehicle downhill energy and increase the endurance of the power battery.

[0068] The present invention collects information of the inclination sensor installed on the vehicle body through the vehicle controller VCU, analyzes whether the vehicle is currently in a downhill state, and converts the slope angle; the vehicle controller VCU converts the weight of the whole vehicle by collecting the weighing sensor information, combines the vehicle speed, friction coefficient, etc., and converts the appropriate electric braking torque of the vehicle through the automobile power calculation formula to keep the vehicle speed below a certain speed when going downhill, and preferentially uses the drive motor to generate electricity and feed back to the power battery to achieve braking. When the driving motor generates insufficient braking force, the retarder intervenes to supplement the corresponding braking torque, and finally achieves automatic steady speed downhill of the electric-driven mining vehicle, and maximizes energy recovery, increases the endurance of the electric-driven mining vehicle, reduces the power battery configuration, and achieves the effect of energy saving, emission reduction and cost reduction.

[0069] ① The formula for calculating the slope angle of the road section where the vehicle is traveling is as follows:

[0070]

[0071] Where: α is the slope angle of the current vehicle driving section;

[0072] A is the current digital value of the inclination sensor detected by the vehicle controller VCU;

[0073] B is the digital value calibrated when the tilt sensor is at zero angle;

[0074] C is the digital value of the inclination sensor when it is tilted 90°.

[0075] When the α angle value is positive, the vehicle is in a climbing state; when the α angle value is negative, the vehicle is in a downhill state.

[0076] ② The calculation formula of the electric braking torque to maintain vehicle speed is as follows:

[0077]

[0078] Where: T is the current required electric braking torque;

[0079] m is the current total vehicle weight;

[0080] g is the value of gravitational acceleration, usually 9.8;

[0081] α is the slope angle of the current vehicle driving section;

[0082] f is the friction coefficient of the road surface in the current road section where the vehicle is located;

[0083] C D is the vehicle drag coefficient;

[0084] A is the frontal area of ​​the vehicle;

[0085] u iis the target vehicle speed to be controlled;

[0086] r is the radius of the vehicle tire;

[0087] i g i0 is the total reduction ratio from the vehicle drive motor to the wheel drive shaft end;

[0088] η T For mechanical transmission efficiency.

[0089] Although the present invention is described herein with reference to the illustrative embodiments of the present invention, the above embodiments are only preferred embodiments of the present invention, and the embodiments of the present invention are not limited to the above embodiments. It should be understood that those skilled in the art can design many other modifications and embodiments, which will fall within the scope and spirit of the principles disclosed in this application.

Claims

1. An electric brake control system for an electric-driven mining dump truck, characterized in that: include: The vehicle controller VCU, the accelerator pedal, the brake pedal, the inclination sensor, the intelligent brake switch, the motor controller, the power battery, the retarder, the drive motor, the weighing sensor, the gearbox and the axle; the vehicle controller VCU is respectively connected with the accelerator pedal, the brake pedal, the inclination sensor, the weighing sensor, the intelligent brake switch, the motor controller, the power battery and the retarder, and the vehicle controller VCU, the motor controller and the power battery form a closed loop in sequence, and the motor controller is also connected with the drive motor, the gearbox and the axle in sequence; The vehicle controller VCU is responsible for collecting the position information of the accelerator pedal and the brake pedal, the control signals of the inclination sensor and the load cell, and the intelligent brake switch, analyzing the driver's control intention, and sending control instructions to the motor controller to drive the vehicle or recover braking energy based on the vehicle speed, vehicle posture and power battery status; and sending control instructions to the retarder to supplement the braking torque; The accelerator pedal is the input interface for the driver to control the vehicle's driving torque, and the brake pedal is the input interface for the driver to control the vehicle's braking torque; The inclination sensor is used to detect the slope angle and positive and negative directions of the slope where the vehicle is located. The vehicle controller VCU can collect the inclination sensor signal and calculate the vehicle posture; The weighing sensor is used to detect the weight of the vehicle load. The vehicle controller VCU can collect the weighing sensor signal and calculate the weight of the vehicle. The motor controller is used to control the operation of the drive motor; The power battery provides energy for the vehicle; the retarder is used to assist braking; the gearbox and axle drive the power of the drive motor, thereby driving the vehicle; The electric brake control system of the electric-driven mining dump truck has a driver control mode and an intelligent brake mode with driver control priority when going downhill, and the intelligent brake switch is used for switching the modes.

2. A method for controlling electric brake of an electric-driven mining dump truck, characterized in that: This is achieved by an electric brake control system for an electric-driven mining dump truck as described in claim 1.

3. The electric brake control method of an electric-driven mining dump truck according to claim 2, characterized in that: The control method comprises: When the smart brake switch is off and the vehicle is in driver control mode when going downhill; The driver controls the vehicle speed by stepping on the brake pedal according to the vehicle speed. The vehicle controller VCU receives the brake pedal depression depth signal, and based on the vehicle speed and the status of the power battery, sends a negative torque command opposite to the motor direction to the motor controller. The motor controller controls the drive motor to generate negative torque to resist rotation. At this time, the drive motor is in power generation mode to charge the power battery.

4. The electric brake control method of an electric-driven mining dump truck according to claim 2, characterized in that: The control method comprises: When the smart brake switch is on and the vehicle is downhill, it is in smart brake mode; The vehicle controller VCU collects information from the inclination sensor to calculate the slope angle of the slope on which the vehicle is located. The vehicle controller VCU collects information from the weighing sensor and calculates the current total vehicle mass in combination with the basic parameters of the vehicle. The vehicle controller VCU calculates the electric braking torque required to maintain the current vehicle speed downhill, and performs PID adjustment on the electric braking torque according to the target vehicle speed. The command of the electric braking torque is sent to the motor controller. The motor controller controls the drive motor to generate negative torque to resist rotation. At this time, the drive motor is in power generation mode to charge the power battery.

5. The electric brake control method of an electric-driven mining dump truck according to claim 4, characterized in that: The control method further includes: When the vehicle is in intelligent braking mode, when the allowable charging power of the power battery is small, and the electric braking torque generated by the motor controller is less than the actual required braking torque, the vehicle controller VCU calculates the insufficient braking torque according to the allowable charging power of the power battery, and sends the insufficient braking torque command to the retarder, and the retarder generates braking torque to make up for the insufficient braking torque.

6. The electric brake control method of an electric-driven mining dump truck according to claim 4, characterized in that: The slope angle calculation formula of the ramp where the vehicle is located is: Where: α is the slope angle of the current vehicle driving section; A is the current digital value of the inclination sensor detected by the vehicle controller VCU; B is the digital value calibrated when the tilt sensor is at zero angle; C is the digital value of the inclination sensor when it is tilted 90°. When the α angle value is positive, the vehicle is in a climbing state; when the α angle value is negative, the vehicle is in a downhill state.

7. The electric brake control method of an electric-driven mining dump truck according to claim 6, characterized in that: The calculation formula for the electric braking torque required to maintain the current vehicle speed downhill is: Where: T is the current required electric braking torque; m is the current total vehicle weight; g is the value of gravitational acceleration; α is the slope angle of the current vehicle driving section; f is the friction coefficient of the road surface in the current road section where the vehicle is located; C D is the vehicle drag coefficient; A is the frontal area of ​​the vehicle; u i is the target vehicle speed to be controlled; r is the radius of the vehicle tire; i g i0 is the total reduction ratio from the vehicle drive motor to the wheel drive shaft end; η T For mechanical transmission efficiency.

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