An electric drive loader constant speed cruise control method and system

Abstract

This invention provides a cruise control method and system for an electric loader. The method includes the following steps: receiving a cruise control command and entering cruise control mode; acquiring the vehicle's current actual speed; matching the vehicle's current actual speed to obtain a safe value for the vehicle's yaw angle; acquiring the vehicle's yaw angle in real time; and exiting cruise control mode if the vehicle's yaw angle exceeds the safe value. In cruise control mode, the system matches the current speed to the safe value for the vehicle's yaw angle and acquires the yaw angle in real time. If the yaw angle exceeds the safe value, the system exits cruise control mode to control the vehicle speed, prevent the electric loader from tipping over, ensure driving safety, and improve the safety of the electric loader.

Description

Technical Field

[0001] This invention relates to a cruise control method and system for an electric loader, belonging to the field of electric loader control technology. Background Technology

[0002] Existing electric loaders with joystick controls lack a cruise control mode. Speed ​​control relies entirely on the driver's subjective use of the accelerator and brake pedals to regulate the motor's output torque. Furthermore, for machinery with its hinge point in the center of the vehicle, sudden speed changes occur during sharp turns or corner exits due to increased drag from greater front-to-rear deflection. This manual control method cannot maintain a stable speed, hindering continuous loading. Additionally, the driver must frequently use the accelerator to control engine speed, resulting in significant workload for prolonged operation.

[0003] There are various cruise control methods for electric vehicles and cruise control methods for fuel-powered loaders in the existing technology. However, due to the characteristics of electric loaders, such as heavy weight, slow speed but fast acceleration and strong output torque, the existing cruise control methods for electric vehicles are not suitable for electric loaders. The weight and speed of the electric loader can easily cause it to tip over and cause accidents. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a cruise control method and system for an electric loader. In cruise control mode, the system matches the current speed with the vehicle body yaw angle safety value and collects the vehicle body yaw angle in real time. If the vehicle body yaw angle exceeds the vehicle body yaw angle safety value, the system exits cruise control mode, controls the vehicle speed, prevents the electric loader from overturning, ensures driving safety, and improves the safety of the electric loader.

[0005] To achieve the above objectives, the present invention is implemented using the following technical solution:

[0006] In a first aspect, the present invention provides a cruise control method for an electric drive loader, comprising the following steps:

[0007] Receive cruise control command and enter cruise control mode;

[0008] Obtain the vehicle's current actual speed;

[0009] The vehicle's actual speed at that moment is used to determine the safe value of the vehicle's deflection angle;

[0010] Real-time acquisition of vehicle body yaw angle;

[0011] If the vehicle's body yaw angle exceeds the safe value, the cruise control mode will be discontinued.

[0012] Furthermore, upon receiving a cruise control command, entering cruise control mode includes:

[0013] Get the cruise control enable switch status. If the cruise control enable switch is active, select to enter cruise control mode. At this time, the vehicle's cruise speed is the vehicle's current actual speed.

[0014] Furthermore, based on the vehicle's actual speed at that moment, a safe value for the vehicle's steering angle is obtained, including:

[0015] When the actual vehicle speed is 0-5km / h, the safe value for the vehicle body deflection angle is 180 degrees.

[0016] When the actual vehicle speed is 5-10 km / h, the safe value for the vehicle body deflection angle is 90 degrees.

[0017] When the actual vehicle speed is 10-20 km / h, the safe value for the vehicle body deflection angle is 60 degrees.

[0018] When the actual vehicle speed is 20-30 km / h, the safe value for the vehicle body deflection angle is 45 degrees.

[0019] When the actual vehicle speed is greater than or equal to 30 km / h, the safe value for the vehicle body deflection angle is 30 degrees.

[0020] Furthermore, the method also includes:

[0021] Obtain the cruise target speed adjustment signal from the cruise mode acceleration / deceleration buttons;

[0022] The cruise target speed is determined based on the cruise target speed adjustment signal from the cruise mode acceleration / deceleration button.

[0023] Adjust the vehicle's actual speed based on the target cruising speed and the vehicle's yaw angle.

[0024] Furthermore, the actual vehicle speed is adjusted based on the target cruising speed and the vehicle's yaw angle, including:

[0025] Real-time acquisition of the vehicle's actual speed;

[0026] If the target speed for cruising is equal to the vehicle's actual speed at the moment, no adjustment is needed; the motor output torque will remain constant.

[0027] If the vehicle's actual speed is less than the target cruise speed, a safe deflection angle is determined based on the target cruise speed. If the vehicle's deflection angle exceeds this safe value, the cruise control mode is exited. Otherwise, the desired pedal opening calculated by the PID controller is increased, and the increased pedal opening is converted to obtain a signal to increase the output torque. This signal is then controlled by the converter to increase the motor's output torque.

[0028] If the vehicle's actual speed is greater than the target cruise speed, a safe deflection angle is calculated based on the actual speed. If the deflection angle exceeds this safe value, the cruise control mode is exited. Otherwise, the desired pedal opening is reduced based on the PID controller, and the reduced pedal opening is converted into a signal to reduce the output torque. This signal is then used to control the motor to output negative torque via the converter.

[0029] Furthermore, the method also includes:

[0030] When the loader is in cruise control mode, the vehicle body yaw angle is obtained in real time.

[0031] The maximum speed of the vehicle at this time is determined based on the vehicle's deflection angle.

[0032] Compare the current cruise target speed with the current vehicle's maximum speed. If the current cruise target speed is greater than the current vehicle's maximum speed, then update the cruise target speed to the current vehicle's maximum speed; otherwise, do not change the cruise target speed.

[0033] Furthermore, the relationship between vehicle yaw angle and maximum speed is as follows:

[0034] When the vehicle's body deflection angle is 0-30 degrees, the maximum speed is 40 km / h;

[0035] When the vehicle's body deflection angle is 30-45 degrees, the maximum speed is 30 km / h;

[0036] When the vehicle's body yaw angle is 45-60 degrees, the maximum speed is 20 km / h;

[0037] When the vehicle's body deflection angle is 60-90 degrees, the maximum speed is 10km / h;

[0038] When the vehicle's body deflection angle is 90-180 degrees, the maximum speed is 5 km / h.

[0039] Furthermore, the method also includes:

[0040] When the loader is in cruise control mode, if the real-time vehicle body yaw angle increases from small to large and does not exceed the safe value of the vehicle body yaw angle, the output pedal opening signal is adjusted to control the motor to provide positive output torque and ensure the cornering speed.

[0041] When the loader is in cruise control mode, if the real-time vehicle body yaw angle decreases from large to small and does not exceed the safe value of the vehicle body yaw angle, the output pedal opening signal is adjusted to control the motor to provide negative output torque and ensure safety when exiting the curve.

[0042] Furthermore, the method also includes:

[0043] When the accelerator pedal status signal or brake pedal status signal is received, exit cruise control mode.

[0044] In a second aspect, the present invention provides a cruise control system for an electric drive loader, comprising:

[0045] Wheel speed sensors are used to collect the vehicle's actual speed at this time;

[0046] A vehicle body angle sensor is installed between the front and rear frames to collect the vehicle body yaw angle.

[0047] Cruise enable switch, used to output cruise control commands;

[0048] The VCU controller is connected to the wheel speed sensor, the angle sensor, and the cruise enable switch, respectively, to perform the control method as described in the first aspect.

[0049] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0050] 1. This invention addresses the characteristics of electric loaders: heavy weight, slow speed but fast acceleration, and strong torque output. In cruise control mode, the current speed is matched with the vehicle yaw angle safety value, and the vehicle yaw angle is collected in real time. If the vehicle yaw angle exceeds the safety value, the cruise control mode is exited to control the vehicle speed, prevent the electric loader from overturning, ensure driving safety, and improve the safety of the electric loader.

[0051] 2. When adjusting the cruise speed, this invention requires that the vehicle body deflection angle meets the requirements of the actual vehicle speed and the target cruise speed, further ensuring driving safety and effectively improving the safety of the electric loader.

[0052] 3. This invention determines the maximum vehicle speed by collecting real-time vehicle body deflection angle, thereby adjusting the cruise target speed of the cruise control, further ensuring driving safety and effectively improving the safety of the electric loader.

[0053] 4. In the process of entering and exiting a curve in cruise control mode, this invention adjusts the output torque of the motor to avoid speed fluctuations when entering and exiting a curve, thereby improving safety.

[0054] 5. This invention enables the electric drive loader to automatically adjust its actual speed in cruise mode. Compared with human intervention, the VCU system obtains the actual speed and compares it with the target speed, providing a driving mode in which the vehicle can travel smoothly at a constant speed in different road sections without requiring any additional operation from the driver.

[0055] 6. This invention effectively avoids driver fatigue and errors caused by frequent pressing of the accelerator and brake pedals during driving, reducing the workload of drivers. This method has the advantages of rapid and precise speed adjustment, offering greater adaptability, accuracy, and safety, preventing improper driver operation, and ensuring driving and operational safety. Attached Figure Description

[0056] Figure 1 This is the cruise control logic diagram;

[0057] Figure 2 This is a schematic diagram of cruise control principle;

[0058] Figure 3 This is a schematic diagram of the specific cruise control process;

[0059] Figure 4 This is a schematic diagram of an electrically driven wheel loader. Detailed Implementation

[0060] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0061] Example 1:

[0062] This embodiment provides a cruise control method for an electric drive loader, the main technical solution and working principle of which are as follows:

[0063] (1) To achieve constant speed control of the entire machine, a closed-loop control method for motor speed is usually adopted. That is, after the engine enters the working state, it maintains a constant speed, and the speed control method relies entirely on the drive motor. A body angle sensor is added between the front and rear frames to detect speed and turning angle in real time to avoid excessive speed causing rollover.

[0064] (2) Information collection and judgment are carried out. The main information collected includes the accelerator pedal status, brake pedal status, cruise enable switch status, cruise acceleration and deceleration status, vehicle angle sensor and other parameters. If the cruise enable switch is effective, cruise can be selected.

[0065] (3) After the loader enters cruise mode, the system collects the actual vehicle speed and real-time vehicle body yaw angle α. The system compares the actual vehicle speed with the speed set in cruise mode, and determines whether the vehicle needs additional output torque and the sign of the output torque based on the vehicle body yaw angle at this time, thereby simulating the increase or decrease of the target accelerator pedal opening. The relationship between the additional output torque and the sign of the output torque and the vehicle body yaw angle is obtained through experimental data calibration.

[0066] Specifically, after the vehicle enters the cruise control setting speed, assuming the vehicle is traveling in a straight line, if the front and rear chassis deflect, this angle change will cause an increase or decrease in driving resistance. The output torque is then fine-tuned based on this change in vehicle body angle. If the vehicle body angle changes, the torque during driving will also be affected. The specific relationship between the change in vehicle body angle and the amount of torque adjustment is obtained through on-site test data calibration.

[0067] (4) Calculate the desired pedal opening using a PID controller.

[0068] (5) Input the desired pedal opening and convert it into the desired output torque. Then, control the motor to output different torques through the converter.

[0069] (6) Continuously adjust the output pedal opening signal based on the actual vehicle speed and real-time vehicle body deflection angle to keep the actual vehicle speed close to the cruise target speed, so as to achieve closed-loop control of vehicle speed.

[0070] (7) When the driver presses the accelerator pedal or brake pedal, or when the vehicle body deflection angle is greater than the preset safe deflection angle, the cruise control state will be discontinued.

[0071] This invention enables electric-drive loaders to automatically adjust their actual speed in cruise mode. Compared to manual intervention, the VCU system acquires the actual vehicle speed and compares it with the target speed, providing a driving mode that allows the vehicle to maintain a constant and stable speed across different road sections without requiring additional driver intervention. This effectively avoids driver fatigue and errors caused by frequent use of the accelerator and brake pedals, reducing the workload of drivers. This method offers the advantages of rapid and precise speed adjustment, providing greater adaptability, accuracy, and safety, preventing improper driver operation, and ensuring driving and operational safety.

[0072] The specific implementation steps of this invention are as follows:

[0073] (1) By collecting parameters of the driving process, including accelerator pedal status, brake pedal status, cruise enable switch status, cruise acceleration and deceleration status and vehicle body angle sensor, if the cruise enable switch is effective, the working machinery can choose to enter cruise mode.

[0074] (2) During cruise mode, the driver can use the cruise enable switch to adjust the cruise speed. The cruise enable switch control panel has cruise mode acceleration and deceleration gear buttons. After entering cruise mode, the actual driving speed and real-time body yaw angle of the vehicle are detected by sensors and fed back to the VCU system for comparison with the target speed set in cruise mode, simulating the increase or decrease of the target accelerator pedal opening.

[0075] (3) If the actual vehicle speed is greater than the target cruising speed and the vehicle body yaw angle is within a safe range, the desired pedal opening calculated by the PID controller is reduced, and the output of the reduced pedal opening is converted to obtain a signal to reduce the output torque. The inverter controls the motor to output negative torque to achieve the purpose of reducing the actual vehicle speed.

[0076] (4) If the actual vehicle speed is less than the target cruising speed and the vehicle body yaw angle is within a safe range, the desired pedal opening calculated by the PID controller is increased. The increased pedal opening output is converted to obtain a signal to increase the output torque. The motor output torque is increased through converter control to achieve the purpose of increasing the actual vehicle speed.

[0077] (5) When the vehicle reaches the preset cruising speed, the speed is finely adjusted according to the vehicle body yaw angle. The specific safety angle is shown in Table 1. When the vehicle body angle increases from small to large, but does not exceed the safety value, the VCU system controls the motor to provide positive output torque to ensure the speed of entering the curve; when the vehicle body angle decreases from large to large, but does not exceed the safety value, the VCU system controls the motor to provide negative output torque to ensure the safety of exiting the curve.

[0078] Table 1 Safety Values ​​for Vehicle Speed ​​and Deflection Angle

[0079] Vehicle speed range (km / h) Vehicle body yaw angle safety value (°) 1 5～10 ＜90 2 10～20 ＜60 3 20～30 ＜45 4 ＞30 ＜30

[0080] When the vehicle's actual speed is at the judgment boundary value, the safety value of the vehicle body deflection angle is calculated according to the higher level.

[0081] (6) Continue to re-enter step (2), the sensor monitors the real-time driving speed and body yaw angle of the vehicle and feeds it back to the VCU system, repeat steps (3)(4)(5) to realize closed-loop control of vehicle speed.

[0082] (7) When the driver presses the accelerator pedal or brake pedal, or when the vehicle body deflection angle is greater than the preset safe deflection angle, the cruise control state will be discontinued.

[0083] Preferably, when the driver needs to increase the target cruising speed in cruise mode, the specific operation method includes:

[0084] (1) When the driver of an electric loader traveling on a flat road section wants to use the existing speed as the cruise speed, he should press the cruise enable switch to enter cruise mode.

[0085] (2) If the driver wants to set the speed to 12km / h in this cruise mode, the driver only needs to set the target value using the corresponding cruise mode acceleration / deceleration buttons. If the vehicle speed is 8km / h and each acceleration button in cruise mode is 2km / h, the driver can press the acceleration button twice to change the cruise mode setting to 12km / h.

[0086] (3) After setting a new cruising speed, if the actual vehicle speed is less than the target cruising speed, the desired pedal opening calculated by the PID controller will increase. The increased pedal opening output will be converted to obtain a signal to increase the output torque. The motor output torque will be increased through the converter control to achieve the purpose of increasing the actual vehicle speed.

[0087] (4) When the driver presses the accelerator pedal or brake pedal, or when the vehicle body deflection angle is greater than the preset safe deflection angle, the cruise control state will be discontinued.

[0088] Preferably, when the driver needs to increase the target cruising speed in cruise mode, the specific operation method includes:

[0089] (1) When driving an electric loader on a continuous curved road section, if the driver wants to use the existing speed as the cruise speed, he should press the cruise enable switch to enter cruise mode.

[0090] (2) If the driver wants to set the speed to 8 km / h in this cruise mode, the driver only needs to set the target value using the corresponding cruise mode acceleration / deceleration button. If the vehicle speed is 12 km / h and each deceleration button in the cruise mode is 2 km / h, the driver can press the deceleration button twice to change the cruise mode setting to 8 km / h. If the vehicle enters a curve and the vehicle body yaw angle α is within the safe range corresponding to this speed, the vehicle will maintain this speed for cruise control.

[0091] (3) After setting a new cruising speed, if the actual vehicle speed is greater than the target cruising speed, the desired pedal opening calculated by the PID controller will decrease. The output of the reduced pedal opening will be converted to obtain a signal to reduce the output torque. The inverter controls the motor to output negative torque in order to reduce the actual vehicle speed.

[0092] (4) When the driver presses the accelerator pedal or brake pedal, or when the vehicle body deflection angle is greater than the preset safe deflection angle, the cruise control state will be discontinued.

[0093] Preferably, when adjusting the cruise control speed, the present invention requires that the vehicle body deflection angle meets the safety value requirements of the vehicle body deflection angle corresponding to the actual vehicle speed and the target cruise speed; otherwise, it exits the cruise control mode, further ensuring driving safety and effectively improving the safety of the electric loader.

[0094] Note that when the loader exits cruise control mode, an alarm signal can be sent to the loader driver to indicate that the cruise control mode has been exited due to the vehicle's yaw angle.

[0095] Optionally, the cruise control method of this embodiment can also adopt a method of updating the cruise target speed in real time according to the vehicle body yaw angle. Specifically, the method of updating the cruise target speed includes:

[0096] Get the vehicle's steering angle in real time;

[0097] The maximum speed of the vehicle at this time is determined based on the vehicle's deflection angle.

[0098] Compare the current cruise target speed with the current vehicle's maximum speed. If the current cruise target speed is greater than the current vehicle's maximum speed, then update the cruise target speed to the current vehicle's maximum speed; otherwise, do not change the cruise target speed.

[0099] The relationship between vehicle body yaw angle and maximum speed is as follows:

[0100] When the vehicle's body deflection angle is 0-30 degrees, the maximum speed is 40 km / h;

[0101] When the vehicle's body deflection angle is 30-45 degrees, the maximum speed is 30 km / h;

[0102] When the vehicle's body yaw angle is 45-60 degrees, the maximum speed is 20 km / h;

[0103] When the vehicle's body deflection angle is 60-90 degrees, the maximum speed is 10km / h;

[0104] When the vehicle's body deflection angle is 90-180 degrees, the maximum speed is 5 km / h.

[0105] When at a boundary value, the lower maximum speed is used.

[0106] This method of updating the cruise target speed can be used in a complementary or equivalent manner to the requirement that the vehicle body deflection angle meets the safety value of the vehicle body deflection angle corresponding to the actual vehicle speed and the target cruise speed, further ensuring driving safety and effectively improving the safety of electric loaders.

[0107] The vehicle control unit (VCU) is the primary controller of the entire machine. The VCU employs a modular design with plug-ins supporting the required functions. The system hardware configuration supports data voltage I / O, including pulse width modulation (PWM), analog voltage input, and the CAN protocol. The VCU contains non-volatile solid-state memory, eliminating the need for a battery, and can store its operating system, runtime applications, persistent machine settings, and historical log data.

[0108] Example 2:

[0109] This embodiment provides a cruise control system for an electric drive loader, such as... Figure 4 As shown, it includes wheel speed sensors, vehicle angle sensors, cruise control enable switch, cruise control acceleration / deceleration buttons, accelerator pedal, brake pedal, wheel brakes, motor, and high-voltage cabinet.

[0110] Wheel speed sensors are used to collect the vehicle's actual speed at any given time;

[0111] The vehicle body angle sensor is installed between the front and rear frames to collect the vehicle body deflection angle;

[0112] The cruise enable switch is used to output cruise control commands;

[0113] The cruise acceleration / deceleration buttons are used to adjust the cruise target speed.

[0114] The high-voltage switchgear functions to convert the three-phase AC power from the vehicle's internal generator into DC power, and then convert the DC power back into AC power for the traction motor. When it receives control signals such as the accelerator pedal, it provides current and torque to the terminal motor. As the core of the terminal control, the high-voltage switchgear is an indispensable device for realizing high-power conversion.

[0115] The function of wheel brakes is to brake the wheels through friction pads when the driver presses the brake pedal;

[0116] The function of the wheel-side motor is to provide output torque for the electric drive of the loader, thereby achieving the purpose of electric drive.

[0117] The VCU controller is connected to the wheel speed sensor, angle sensor, and cruise enable switch, respectively, and is used to execute the control method described in Example 1:

[0118] The VCU controller collects parameters of the driving process, including accelerator pedal status, brake pedal status, cruise enable switch status, cruise acceleration and deceleration status, and vehicle angle sensor status. If the cruise enable switch is active, the working machinery can be selected to enter cruise mode.

[0119] (2) During cruise mode, the driver can use the cruise enable switch to adjust the cruise speed. The cruise enable switch control panel has cruise mode acceleration and deceleration gear buttons. After entering cruise mode, the actual driving speed and real-time body yaw angle of the vehicle are detected by sensors and fed back to the VCU system for comparison with the target speed set in cruise mode, simulating the increase or decrease of the target accelerator pedal opening.

[0120] (3) If the actual vehicle speed is greater than the target cruising speed and the vehicle body yaw angle is within a safe range, the desired pedal opening calculated by the PID controller is reduced. The VCU controller converts the output of the reduced pedal opening to obtain a signal to reduce the output torque. The inverter controls the motor to output negative torque to achieve the purpose of reducing the actual vehicle speed.

[0121] (4) If the actual vehicle speed is less than the target cruising speed and the vehicle body yaw angle is within a safe range, the desired pedal opening calculated by the PID controller is increased. The VCU controller converts the increased pedal opening output to obtain a signal to increase the output torque. The motor output torque is increased through the converter control to achieve the purpose of increasing the actual vehicle speed.

[0122] (5) When the vehicle reaches the preset cruising speed, the speed is finely adjusted according to the vehicle body yaw angle. The specific safety angle is shown in Table 1. When the vehicle body angle increases from small to large, but does not exceed the safety value, the VCU system controls the motor to provide positive output torque to ensure the speed of entering the curve; when the vehicle body angle decreases from large to large, but does not exceed the safety value, the VCU system controls the motor to provide negative output torque to ensure the safety of exiting the curve.

[0123] Table 1 Safety Values ​​for Vehicle Speed ​​and Deflection Angle

[0124] Vehicle speed range (km / h) Vehicle body yaw angle safety value (°) 1 5～10 ＜90 2 10～20 ＜60 3 20～30 ＜45 4 ＞30 ＜30

[0125] When the vehicle's actual speed is at the judgment boundary value, the safety value of the vehicle body deflection angle is calculated according to the higher level.

[0126] (6) Continue to re-enter step (2), the sensor monitors the real-time driving speed and body yaw angle of the vehicle and feeds it back to the VCU system, repeat steps (3)(4)(5) to realize closed-loop control of vehicle speed.

[0127] (7) When the driver presses the accelerator pedal or brake pedal, or when the vehicle body deflection angle is greater than the preset safe deflection angle, the cruise control state will be discontinued.

[0128] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0129] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0130] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0131] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0132] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for cruise control of an electric-driven loader, characterized in that, Includes the following steps: Receive cruise control command and enter cruise control mode; Obtain the vehicle's current actual speed; The vehicle's actual speed at that moment is used to determine the safe value of the vehicle's deflection angle; Real-time acquisition of vehicle body yaw angle; If the vehicle's body yaw angle exceeds the safe value, then exit cruise control mode. The method further includes: When the loader is in cruise control mode, the vehicle body yaw angle is obtained in real time. The maximum speed of the vehicle at this time is determined based on the vehicle's deflection angle. Compare the current cruise target speed with the current vehicle's maximum speed. If the current cruise target speed is greater than the current vehicle's maximum speed, then update the cruise target speed to the current vehicle's maximum speed; otherwise, do not change the cruise target speed. The relationship between vehicle body yaw angle and maximum speed is as follows: When the vehicle's body deflection angle is 0-30 degrees, the maximum speed is 40 km / h; When the vehicle's body deflection angle is 30-45 degrees, the maximum speed is 30 km / h; When the vehicle's body yaw angle is 45-60 degrees, the maximum speed is 20 km / h; When the vehicle's body deflection angle is 60-90 degrees, the maximum speed is 10km / h; When the vehicle's body deflection angle is 90-180 degrees, the maximum speed is 5 km / h; The method further includes: When the loader is in cruise control mode, if the real-time vehicle body yaw angle increases from small to large and does not exceed the safe value of the vehicle body yaw angle, the output pedal opening signal is adjusted to control the motor to provide positive output torque and ensure the cornering speed. When the loader is in cruise control mode, if the real-time vehicle body yaw angle decreases from large to small and does not exceed the safe value of the vehicle body yaw angle, the output pedal opening signal is adjusted to control the motor to provide negative output torque and ensure safety when exiting the curve.

2. The cruise control method for an electric drive loader according to claim 1, characterized in that, Upon receiving a cruise control command, enter cruise control mode, including: Get the cruise control enable switch status. If the cruise control enable switch is active, select to enter cruise control mode. At this time, the vehicle's cruise speed is the vehicle's current actual speed.

3. The cruise control method for an electric drive loader according to claim 1, characterized in that, The vehicle's actual speed at that moment is used to determine the safe value of the vehicle's yaw angle, including: When the actual vehicle speed is 0-5km / h, the safe value for the vehicle body deflection angle is 180 degrees. When the actual vehicle speed is 5-10 km / h, the safe value for the vehicle body deflection angle is 90 degrees. When the actual vehicle speed is 10-20 km / h, the safe value for the vehicle body deflection angle is 60 degrees. When the actual vehicle speed is 20-30 km / h, the safe value for the vehicle body deflection angle is 45 degrees. When the actual vehicle speed is greater than or equal to 30 km / h, the safe value for the vehicle body deflection angle is 30 degrees.

4. The cruise control method for an electric drive loader according to claim 1, characterized in that, The method further includes: Obtain the cruise target speed adjustment signal from the cruise mode acceleration / deceleration buttons; The cruise target speed is determined based on the cruise target speed adjustment signal from the cruise mode acceleration / deceleration button. Adjust the vehicle's actual speed based on the target cruising speed and the vehicle's yaw angle.

5. The cruise control method for an electric drive loader according to claim 4, characterized in that, Adjusting the vehicle's actual speed based on the target cruising speed and vehicle yaw angle, including: Real-time acquisition of the vehicle's actual speed; If the target speed for cruising is equal to the vehicle's actual speed at the moment, no adjustment is needed; the motor output torque will remain constant. If the vehicle's actual speed is less than the cruise target speed, a safe value for the vehicle's body yaw angle is obtained based on the cruise target speed. If the vehicle's body yaw angle is greater than the safe value, the cruise control mode is exited. Otherwise, the desired pedal opening is increased by the PID controller, and the increased pedal opening is converted to obtain a signal to increase the output torque. The motor output torque is then increased by the converter control. If the vehicle's actual speed is greater than the target cruise speed, a safe value for the vehicle's body yaw angle is obtained based on the actual speed. If the vehicle's body yaw angle is greater than this safe value, the cruise control mode is exited. Otherwise, the desired pedal opening is reduced by the PID controller, and the output of the reduced pedal opening is converted to obtain a signal to reduce the output torque. The inverter then controls the motor to output negative torque.

6. The cruise control method for an electric drive loader according to claim 1, characterized in that, The method further includes: When the accelerator pedal status signal or brake pedal status signal is received, exit cruise control mode.

7. A cruise control system for an electric drive loader, characterized in that, include: Wheel speed sensors are used to collect the vehicle's actual speed at this time; A vehicle body angle sensor is installed between the front and rear frames to collect the vehicle body yaw angle. Cruise enable switch, used to output cruise control commands; The VCU controller is connected to the wheel speed sensor, the angle sensor and the cruise enable switch respectively, and is used to execute the control method as described in any one of claims 1-6.

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