A control system and method for an electric tricycle with multi-level automatic speed regulation

Abstract

This application relates to the technical field of controlling or regulating electric motors, and provides a control system and method for an electric tricycle with multi-stage automatic speed regulation. The system includes: a drive motor, a gearshift motor, a central controller, a gearbox, and a clutch; the drive motor is connected to the gearbox through the clutch, and the gearbox is connected to the drive wheels of the electric tricycle for outputting the driving torque of the drive motor to the drive wheels of the electric tricycle; the gearshift motor is connected to the gearbox through a switching device for gear range adjustment; the central controller is respectively connected to the drive motor and the gearshift motor for detecting the operating states of the drive motor and the gearshift motor, so as to adjust the speed of the electric tricycle according to the operating states. Among them, both the drive motor and the gearshift motor are brushless DC motors. Thus, it is possible to select the optimal gear range while ensuring that the maximum current of the drive motor is not exceeded, ensuring the safe forward driving of the electric tricycle and at the same time ensuring its safe operation.

Description

Technical Field

[0001] This application relates to the technical field of controlling or regulating motors, and particularly to a control system and method for an electric tricycle with multi-stage automatic speed regulation. Background Art

[0002] Brushless DC motors are widely used in electric tricycles due to their simple structure, long lifespan, and low maintenance cost.

[0003] Currently, a brushless DC motor is directly connected to the rotating shaft of an electric tricycle, and the driving speed of the electric tricycle is controlled by adjusting the speed of the brushless DC motor. Below the base speed, the brushless DC motor usually operates in a constant torque mode, and free speed switching can be performed according to the operator's needs as long as the load torque does not exceed the electromagnetic torque. When the road condition is good and the load torque is light, the brushless DC motor can operate in a constant power mode, and the speed can be increased by field weakening control to improve the driving speed of the electric tricycle. However, when the road condition is poor, especially when the slope of an uphill is large, the load torque often exceeds the maximum torque that the brushless DC motor can provide, resulting in the inability to climb the slope and even burning out the brushless DC motor.

[0004] Therefore, an improved technical solution is needed to address the deficiencies of the above-mentioned existing technologies. Summary of the Invention

[0005] The purpose of this application is to provide a control system and method for an electric tricycle with multi-stage automatic speed regulation to solve or alleviate the problems existing in the above-mentioned existing technologies.

[0006] To achieve the above purpose, this application provides the following technical solutions:

[0007] This application provides a control system for an electric tricycle with multi-stage automatic speed regulation, including: a driving motor, a gear shifting motor, a central controller, a gearbox, and a clutch;

[0008] The driving motor is connected to the gearbox through the clutch, and the gearbox is connected to the driving wheel of the electric tricycle, and is used to output the driving torque of the driving motor to the driving wheel of the electric tricycle;

[0009] The gear shifting motor is connected to the gearbox through a switching device and is used for gear range adjustment;

[0010] The central controller is respectively connected to the driving motor and the gear shifting motor through a driving module and a detection circuit, and is used to detect the operating states of the driving motor and the gear shifting motor, and adjust the speed of the electric tricycle through the driving module according to the operating states, wherein both the driving motor and the gear shifting motor are brushless DC motors.

[0011] Preferably, the system further includes a throttle grip;

[0012] The throttle grip is used to input an operation instruction, and the operation instruction is used to instruct the drive motor and the motor to perform corresponding operations to change the running speed of the electric tricycle;

[0013] Wherein, the operating modes of the drive motor include six modes: neutral, low speed, medium speed, high speed, reverse gear and brake, and the gear ranges of the gearbox are divided into neutral and gears 1 to 5, corresponding to six positions of the gear shift motor.

[0014] Preferably, the central controller includes an instruction input module, and the instruction input module is used to detect the rotation angle of the throttle grip, so as to determine the operation instruction according to the rotation angle of the throttle grip, and determine the running mode of the electric tricycle in combination with the gear switch; the drive module includes the drive circuit of the drive motor and the drive circuit of the gear shift motor;

[0015] The central controller sends drive signals to the drive circuit of the drive motor and the drive circuit of the gear shift motor respectively according to the running mode of the electric tricycle, the stator current of the drive motor and the gear state of the gear shift motor, and then controls the drive motor and the gear shift motor to determine the running mode of the electric tricycle.

[0016] Preferably, the central controller further includes a current detection module, and the current detection module is used to detect the stator winding current of the drive motor in real time, so that the central controller sends a drive signal to the drive circuit of the gear shift motor according to the stator winding current, and controls the gear shift motor to select the gear of the gearbox, so as to realize the automatic adjustment of the speed of the electric tricycle.

[0017] Preferably, when the running mode is in the high-speed forward mode, the central controller is specifically used to judge whether the stator winding current is greater than the maximum current of the drive motor. If so, a drive signal is sent to the drive circuit of the gear shift motor to drive the gear shift motor to automatically lower the gear range of the gearbox by one gear. If the stator winding current is still greater than the maximum current of the drive motor after lowering the gear range by one gear, the gear shift motor is driven to continue to automatically lower the gear range of the gearbox by one gear until the stator winding current meets the maximum current requirement of the motor or switches to the first gear.

[0018] If the stator winding current of the drive motor is still greater than the maximum current of the drive motor after the gear range of the gearbox is lowered to the first gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit of the drive motor until the drive voltage is zero and the drive motor stops rotating.

[0019] Preferably, when the operation mode is in the medium-speed forward mode, the central controller is specifically configured to send a driving signal to the driving circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a driving signal to the driving circuit of the driving motor to drive the driving motor to operate at half of the base speed;

[0020] The current detection module real-time detects the stator winding current of the driving motor, and drives the gear-shifting motor to automatically switch the gear range of the gearbox according to the stator winding current until the operation mode changes.

[0021] Preferably, when the operation mode is in the low-speed forward mode, the central controller is specifically configured to send a driving signal to the driving circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a driving signal to the driving motor to drive the driving motor to operate at one-fourth of the base speed;

[0022] The current detection module real-time detects the stator winding current of the driving motor, and drives the gear-shifting motor to automatically switch the gear range of the gearbox according to whether the stator winding current exceeds the maximum current of the driving motor until the operation mode changes.

[0023] Preferably, the central controller further includes a speed detection module; the speed detection module is used to detect the speed of the driving motor.

[0024] Preferably, the gear-shifting motor is a permanent magnet brushless DC motor with a power not greater than 50W.

[0025] The embodiment of the present application provides a control method for a multi-stage automatically speed-adjustable electric tricycle, including:

[0026] Step S101, detecting the state of the handlebar of the electric tricycle to determine the operation mode of the electric tricycle;

[0027] Step S102, in response to the operation mode being in the high-speed forward mode, determining whether the stator winding current of the driving motor is greater than the maximum current of the driving motor. If so, send a driving signal to the driving circuit of the gear-shifting motor to drive the gear-shifting motor to automatically lower the gear range of the gearbox by one gear. If the stator winding current is still greater than the maximum current of the driving motor after lowering the gear range by one gear, drive the gear-shifting motor to continue to automatically lower the gear range of the gearbox until the stator winding current meets the requirement of not exceeding the maximum current of the driving motor;

[0028] Step S103: In response to the running mode being in the medium-speed forward mode, send a driving signal to the driving circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a driving signal to the driving circuit of the driving motor to drive the driving motor to operate at half of the base speed; detect the stator winding current of the driving motor in real time, and determine whether it exceeds the maximum current of the driving motor based on the stator winding current to drive the gear-shifting motor to automatically perform gear range switching of the gearbox until the running mode changes;

[0029] Step S104: In response to the running mode being in the low-speed forward mode, send a driving signal to the driving circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a driving signal to the driving circuit of the driving motor to drive the driving motor to operate at one-fourth of the base speed; detect the stator winding current of the driving motor in real time, and based on whether the stator winding current exceeds the maximum current of the driving motor, drive the gear-shifting motor to automatically perform gear range switching of the gearbox until the running mode changes.

[0030] Beneficial effects:

[0031] In this application, the clutch, gearbox, and driving brushless DC motor are combined, and a small-power brushless DC motor is additionally used for gear range adjustment to achieve the purpose of increasing the driving torque at low speeds. When the electric tricycle encounters poor road conditions and needs to provide a large load torque, the system detects the stator winding current of the brushless DC in real time. Without exceeding the maximum current of the brushless DC motor, the optimal gear range is selected to ensure the forward movement of the electric tricycle and the safe operation of the system. Description of the Drawings

[0032] The schematic diagrams of the specification drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments and descriptions of this application are used to explain this application and do not constitute an improper limitation to this application. Among them:

[0033] Figure 1 It is a schematic structural diagram of a multi-stage automatic speed regulation control system for an electric tricycle according to some embodiments of this application;

[0034] Figure 2 It is a schematic diagram of the gear position switch, throttle grip, and gear range of the gearbox according to some embodiments of this application;

[0035] Figure 3 It is a schematic diagram of the gear range coordination and switching process according to some embodiments of this application;

[0036] Figure 4 It is a schematic diagram of the automatic gear shifting process according to some embodiments of this application;

[0037] Figure 5 Schematic diagram of an accident handling mode process provided according to some embodiments of the present application. Detailed implementation manners

[0038] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0039] Exemplary system

[0040] Embodiments of the present application provide a control system for an electric tricycle with multi-level automatic speed regulation, as Figure 1 , Figure 2 shown. The system includes: a driving motor, a gear-shifting motor, a central controller, a gearbox, and a clutch.

[0041] Among them, the driving motor is connected to the gearbox through the clutch, and the gearbox is connected to the driving wheels of the electric tricycle, and is used to output the driving torque of the driving motor to the driving wheels of the electric tricycle; the gear-shifting motor is connected to the gearbox through a switching device and is used for gear range adjustment; the central controller is respectively connected to the driving motor and the gear-shifting motor through a driving module and a detection circuit, and is used to detect the operating states of the driving motor and the gear-shifting motor, so as to adjust the speed of the electric tricycle through the driving module according to the operating states. Among them, both the driving motor and the gear-shifting motor are brushless DC motors.

[0042] Figure 1 Schematic diagram of the structure of the control system for an electric tricycle with multi-level automatic speed regulation of the present application, as Figure 1 shown. The brushless DC motor (i.e., the driving motor) driving the electric tricycle is connected through the clutch and the gearbox, and further outputs the driving torque to the driving wheels of the electric tricycle. The small-power brushless DC motor for speed regulation (i.e., the gear-shifting motor) is connected to the gearbox through a switching device and is used for gear range adjustment.

[0043] Among them, the control object of the gear-shifting motor is the gearbox, and it has 6 Hall elements to indicate the gear range. The driving motor is the power source of the electric tricycle, and outputs torque to the driving wheels of the tricycle through the gearbox. The central controller sends driving signals to the driving circuits of the gear-shifting motor and the driving motor to control the actions of the two. Only the stator current of the driving motor is detected to avoid overcurrent.

[0044] With the above system, the clutch, gearbox, and drive brushless DC motor are combined, and a small power brushless DC motor is additionally used as a gear shift motor for gear range adjustment to achieve the purpose of increasing the drive torque at low speeds. When the electric tricycle encounters poor road conditions, such as a large slope when going uphill and a large load torque needs to be provided, the central controller of the system real-time detects the stator winding current of the drive motor, and selects the optimal gear range without exceeding the maximum current of the drive motor to ensure the forward movement of the electric tricycle and the safe operation of the system.

[0045] Based on the above solution, the system further includes a throttle grip, which is used to input operation instructions. The operation instructions are used to instruct the drive motor and the motor to perform corresponding operations to change the running speed of the electric tricycle. Among them, the running modes of the drive motor include 6 modes: neutral, low speed, medium speed, high speed, reverse gear, and brake. The gear range of the gearbox is divided into neutral and gears 1 to 5, corresponding to 6 positions of the gear shift motor.

[0046] Exemplarily, Figure 2 FIG. is a schematic diagram of the gear switch, throttle grip, and gear range of the gearbox according to some embodiments of the present application. As Figure 2 shown, the gears of the electric tricycle are controlled by a gear switch, and the gear switch is set to three modes: neutral, reverse, and forward. Combining the brake mode, there are a total of four running modes for the electric tricycle. The running modes of the drive motor are divided into 6 modes: neutral, low speed, medium speed, high speed, reverse gear, and brake. The throttle grip is provided with three modes: low, medium, and high, corresponding to the low speed, medium speed, and high speed of the drive motor respectively. At the same time, according to the gearbox structure, the gear range of the gearbox is divided into gears 1 to 5 and neutral, corresponding to 6 positions of the gear shift motor respectively.

[0047] Based on Figure 2 the system shown, the inputs affecting the system running mode include: gear switch, throttle grip, brake signal, and stator current of the drive motor. Among them, when the electric tricycle is not running, the system is in the neutral mode.

[0048] When the operator sets the gear switch to the reverse mode, the gearbox must be in the first gear, and the drive motor runs at the reverse base speed until the reverse operation is completed and the operator switches the mode.

[0049] When the gear switch is in the forward mode, the operator controls the throttle grip to command the electric tricycle to move forward at low speed, medium speed, and high speed.

[0050] In order to make the speed adjustment of the electric tricycle more intelligent, in some embodiments, the central controller includes an instruction input module. The instruction input module is used to detect the rotation angle of the throttle grip, determine the operation instruction according to the rotation angle of the throttle grip, and combine with the gear switch to determine the operation mode of the drive motor. The drive module includes the drive circuit of the drive motor and the drive circuit of the gear shift motor. The central controller is also used to send drive signals to the drive circuit of the drive motor and the drive circuit of the gear shift motor according to the operation mode of the drive motor, the stator current of the drive motor, and the gear state of the gear shift motor.

[0051] In the implementation of this application, when the gear switch is in the forward mode, the operator twists the throttle grip to change its angle, so as to input different voltage signals to the system. The instruction input module uses the Hall effect to detect the voltage signal input by the operator, and determines the throttle grip state according to the voltage signal, that is, judges which of the low, medium, and high modes the throttle grip is in, and uses it as an input instruction to determine the operation mode of the drive motor.

[0052] As can be seen from the foregoing description, the operation modes of the drive motor are divided into low speed, medium speed, and high speed. That is to say, the speed of the drive motor is divided into three sections: low speed, medium speed, and high speed, and the gearbox is divided into 1 to 5 gears. By matching the drive motor with the gearbox, 3×5 = 15 speeds can be obtained. The operation instruction can be determined through the throttle grip state, and then the operation mode of the electric tricycle can be determined. At this time, the drive module sends drive signals to the drive circuit of the drive motor and the drive circuit of the gear shift motor according to the operation mode of the electric tricycle, the stator current of the drive motor, and the gear state of the gear shift motor, so as to drive the electric tricycle to travel safely.

[0053] Furthermore, in some embodiments, the central controller further includes a current detection module. The current detection module is used to detect the stator winding current of the drive motor in real time, so that the central controller sends a drive signal to the gear shift motor according to whether the stator winding current exceeds the maximum current of the drive motor to select the gear of the gearbox, so as to realize the automatic adjustment of the speed of the electric tricycle.

[0054] On the basis of the foregoing solution, if the gear switch is in the forward mode, the electric tricycle includes three operation modes: high-speed forward, medium-speed forward, and low-speed forward.

[0055] When the operation mode of the electric tricycle is in the high-speed forward mode, the central controller is specifically used to judge whether the stator winding current is greater than the maximum current of the drive motor. If so, a drive signal is sent to the drive circuit of the gear shift motor to drive the gear shift motor to automatically reduce the gear of the gearbox by one gear. If the stator winding current is still greater than the maximum current of the drive motor after reducing the gear by one gear, the gear shift motor is driven to continue to automatically reduce the gear of the gearbox by one gear until the stator winding current meets the maximum current requirement of the motor or switches to the first gear.

[0056] If the stator current of the drive motor is still over-limit after the gearbox is shifted to the first gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit until the drive voltage is zero and the drive motor stops rotating.

[0057] In practice, when the operator turns the throttle to send an input command to the electric tricycle to command the electric tricycle to move forward at the maximum speed, that is, when the operation mode is in the high-speed forward mode, the gearshift motor places the gearbox in the maximum gear range. Based on the real-time detection of the stator winding current of the drive motor, the central controller quickly reaches the rated speed, that is, the base speed, with the maximum torque that the drive motor can provide. If the stator winding current of the drive motor exceeds the maximum current at this time, the gearbox automatically downshifts one gear range. If the stator winding current of the drive motor still exceeds the maximum current, the gearbox continues to downshift until the stator winding current of the drive motor meets the maximum current requirement or the gearbox is shifted to the first gear.

[0058] If the stator current of the drive motor is still over-limit after the gearbox is shifted to the first gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit until the drive voltage is zero and the drive motor stops rotating.

[0059] When the operation mode is in the medium-speed forward mode, the central controller is specifically used to send a drive signal to the drive circuit of the gearshift motor to adjust its gear range to the fifth gear, and send a drive signal to the drive circuit of the drive motor to make the drive motor run at half of the base speed; the current detection module real-time detects the stator winding current of the drive motor, and automatically switches the gear range of the gearshift motor according to whether the stator winding current exceeds the maximum current of the drive motor until the operation mode changes.

[0060] Specifically, when the operator turns the throttle to command the electric tricycle to move forward at a medium speed, the central controller sends a drive signal to the drive circuit of the gearshift motor to rotate it to the position of the fifth gear. Correspondingly, the gear range of the gearbox is also in the fifth gear. At this time, the drive motor runs at half of the base speed, and at the same time, the stator winding current of the drive motor is real-time detected. If the stator winding current of the drive motor exceeds the maximum current, it continues to downshift until the stator winding current of the drive motor meets the maximum current requirement or is shifted to the first gear.

[0061] If the stator current of the drive motor is still over-limit after the gearbox is shifted to the first gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit until the drive voltage is zero and the drive motor stops rotating.

[0062] When the operation mode is in the low-speed forward mode, the central controller is specifically configured to send a drive signal to the drive circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a drive signal to the drive circuit of the drive motor to make the drive motor operate at a quarter of the base speed; the current detection module continuously detects the stator winding current of the drive motor and automatically switches the gear range of the gear-shifting motor according to whether the stator winding current exceeds the maximum current of the drive motor until the operation mode changes.

[0063] Specifically, when the operator twists the throttle to command the electric tricycle to move forward at a low speed, the central controller is specifically configured to send a drive signal to the drive circuit of the gear-shifting motor to rotate it to the position of the 5th gear. Correspondingly, the gear range of the gearbox is also in the 5th gear. At this time, the drive motor operates at a quarter of the base speed, and at the same time, continuously detects the stator winding current of the drive motor. If the stator winding current of the drive motor exceeds the maximum current, the gear will be downshifted continuously until the stator winding current of the drive motor meets the maximum current requirement or drops to the 1st gear.

[0064] If the stator current of the drive motor is still over-limit after the gearbox drops to the 1st gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit until the drive voltage is zero and the drive motor stops rotating.

[0065] It should be understood that the vehicle also has a need to decelerate when moving forward. During driving, when the operator brakes, it enters the braking mode. At this time, the central controller judges the operation mode of the drive motor. If the gearbox is in the 2nd to 5th gears, the central controller sets the duty ratio of the drive voltage of the drive motor to 30%, and at the same time, the gear-shifting motor performs a downshifting operation on the gearbox. If the brake signal persists, the above actions are repeated continuously until the gear-shifting motor shifts the gearbox down to the 1st gear. If the stator current of the drive motor is still over-limit after the gearbox drops to the 1st gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit until the drive voltage is zero and the drive motor stops rotating.

[0066] Furthermore, the central controller further includes a speed detection module and a position detection module. Among them, the speed detection module is used to detect the speed of the drive motor as a feedback signal for the control of the drive motor. The position detection module uses Hall elements to detect the rotor position of the drive motor and the gear position of the gear-shifting motor.

[0067] Specifically, the rotational speed detection module feeds back the detected rotational speed of the drive motor to the central controller as a feedback signal for drive motor speed control. The position detection module includes two parts: the position detection of the gear shifting motor and the position detection of the throttle grip. Among them, the position detection of the gear shifting motor is used to detect the Hall element in the gear shifting motor to determine the gear position of the gear shifting motor, and further determine the current gear range of the gearbox. The position detection of the throttle grip is used to determine the position of the throttle grip to judge the control intention of the operator. The central controller controls the drive motor at high speed, medium speed, and low speed according to the detection results of the rotational speed detection module and the position detection module.

[0068] Some embodiments of the present application also provide a level protection function. Specifically, the level voltage range is divided into three gears: greater than 52.5V, full charge; 50V - 52.5V, medium charge; less than 50V, low charge. When starting, first detect the level voltage. When in the low charge state, starting is prohibited and an alarm is given. Only when in the medium charge or full charge state can it start.

[0069] In some embodiments, the gear shifting motor is a permanent magnet brushless DC motor with a power not greater than 50W. Using a small - power permanent magnet brushless DC motor as the gear shifting motor can save power consumption.

[0070] In summary, the multi - level automatic speed - regulation electric tricycle control system of the embodiments of the present application includes a drive motor, a gear shifting motor, a central controller, a gearbox, and a clutch. The drive motor is connected to the gearbox through the clutch, and the gearbox is connected to the drive wheels of the electric tricycle for outputting the driving torque of the drive motor to the drive wheels of the electric tricycle. The gear shifting motor is connected to the gearbox through a switching device for gear range adjustment. The central controller is respectively connected to the drive motor and the gear shifting motor through a drive module and a detection circuit to detect the operating states of the drive motor and the gear shifting motor, and adjust the speed of the electric tricycle according to the operating states. Among them, both the drive motor and the gear shifting motor are brushless DC motors. Thus, it is possible to select the optimal gear range while ensuring that the maximum current of the drive motor is not exceeded, ensuring the safe forward driving of the electric tricycle and its safe operation at the same time.

[0071] Exemplary method

[0072] The embodiments of the present application also provide a control method for a multi - level automatic speed - regulation electric tricycle, as Figure 3 、 Figure 4 、 Figure 5 shown. This method includes:

[0073] Step S101, detecting the state of the throttle grip of the electric tricycle to determine the operating mode of the electric tricycle;

[0074] Step S102: In response to the operation mode being in the high-speed forward mode, determine whether the stator winding current of the drive motor is greater than the maximum current of the drive motor. If so, send a drive signal to the drive circuit of the gear-shifting motor to drive the gear-shifting motor to automatically downshift the transmission by one gear. If the stator winding current is still greater than the maximum current of the drive motor after the transmission downshifts by one gear, drive the gear-shifting motor to continue automatically downshifting by one gear or reduce the duty ratio of the drive voltage until the stator winding current meets the safe driving requirements;

[0075] Step S103: In response to the operation mode being in the medium-speed forward mode, send a drive signal to the drive circuit of the gear-shifting motor to adjust the gear position of the transmission to the 5th gear, and send a drive signal to the drive circuit of the drive motor to make the drive motor operate at half of the base speed; continuously detect the stator winding current of the drive motor, and drive the gear-shifting motor to automatically switch the gear position according to whether the stator winding current exceeds the maximum current of the drive motor until the operation mode changes;

[0076] Step S104: In response to the operation mode being in the low-speed forward mode, send a drive signal to the drive circuit of the gear-shifting motor to adjust its gear position to the 5th gear, and send a drive signal to the drive circuit of the drive motor to make the drive motor operate at one-quarter of the base speed; continuously detect the stator winding current of the drive motor, and drive the gear-shifting motor to automatically switch the gear position according to whether the stator winding current exceeds the maximum current of the drive motor until the operation mode changes.

[0077] When the electric tricycle is not running, the system is in the neutral gear mode. As Figure 3 shown, when the electric tricycle starts to run, first determine whether the electric tricycle is abnormal, that is, whether the motor tricycle is in an error or fault state. If it is in an error or fault state, enter the fault handling sub-process. Otherwise, further detect the battery state of the electric tricycle. If the battery state is abnormal, enter the fault handling sub-process. If the battery state is normal, then judge the voltage and the throttle state to determine the gear position of the electric tricycle, and then determine the operation mode of the electric tricycle.

[0078] If the gear switch is in the neutral gear, return and wait for the operator to switch the gear to other modes.

[0079] If the gear switch is in the reverse gear, the transmission must be in the 1st gear, and the drive motor runs in the reverse base speed until the reverse gear operation is completed and the operator switches the mode.

[0080] If the gear switch is in the forward gear position, determine which of the low, medium, and high modes the throttle is in according to the throttle state, and then judge the operation mode of the electric tricycle, and automatically adjust the gear position of the transmission through the gear-shifting motor according to the operation mode of the electric tricycle.

[0081] If a braking signal is received, the gearshift motor adjusts the transmission to the first gear. After the drive motor reduces its speed to 30%, it gradually stops.

[0082] If the operating mode of the electric tricycle cannot be determined, the accident handling mode is entered.

[0083] Further, when the gear switch is in the forward gear range, the gear range of the transmission needs to be automatically adjusted by the gearshift motor according to the operating mode of the electric tricycle. The detailed steps are as Figure 4 follows: First, detect the current speed and stator winding current of the drive motor, and determine whether the stator winding current exceeds the maximum current. If it does not exceed the maximum current, the gearshift motor lowers the transmission by one gear, and determine whether the lowered gear range of the transmission exceeds the gear range limit, that is, determine whether the gear range is lower than the first gear. If so, place the transmission in neutral and send an error alarm. If the lowered gear range does not exceed the gear range limit, return and execute the steps of detecting the current speed and stator winding current of the drive motor again and the subsequent steps until the stator winding current of the drive motor meets the maximum current requirement or drops to the first gear.

[0084] If the transmission drops to the first gear and the stator current of the drive motor is still over-limit, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit until the drive voltage is zero and the drive motor stops rotating.

[0085] Further, in the above steps, after entering the accident handling mode, the handling mode includes the steps as Figure 5 follows: Within a preset time interval (i.e., delay for a period of time), detect whether the accident still exists. If so, search for the accident code. If the accident code is found, store the accident fault information and give an alarm prompt; if the accident code is not found, give an alarm prompt for an unknown accident fault. If the accident fault disappears within the preset time interval, start the electric tricycle normally.

[0086] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An electric tricycle control system with multi-stage automatic speed regulation, characterized in that, Including: A drive motor, a gear shift motor, a central controller, a gearbox, and a clutch; The drive motor is connected to the gearbox through the clutch, and the gearbox is connected to the drive wheels of the electric tricycle, and is used to output the driving torque of the drive motor to the drive wheels of the electric tricycle; The gear shift motor is connected to the gearbox through a switching device and is used for gear range adjustment; The central controller is respectively connected to the drive motor and the gear shift motor through a drive module and a detection circuit, and is used to detect the operating states of the drive motor and the gear shift motor, so as to adjust the speed of the electric tricycle through the drive module according to the operating states. Wherein, the drive motor and the gear shift motor are both brushless DC motors; The central controller further includes a current detection module, and the current detection module is used to detect the stator winding current of the drive motor in real time, so that the central controller sends a signal to the drive circuit of the gear shift motor according to whether the stator winding current exceeds the maximum current of the drive motor, and controls the gear shift motor to perform gear selection of the gearbox, thereby realizing automatic adjustment of the speed of the electric tricycle; When the operating mode of the electric tricycle is in the high-speed forward mode, the central controller is specifically used to judge whether the stator winding current is greater than the maximum current of the drive motor. If so, a drive signal is sent to the drive circuit of the gear shift motor to drive the gear shift motor to automatically lower the gear range of the gearbox by one gear. If the stator winding current is still greater than the maximum current of the drive motor after lowering the gear range by one gear, the gear shift motor is driven to continue to automatically lower the gear range of the gearbox by one gear until the stator winding current meets the maximum current requirement of the motor or the gearbox switches to the first gear; If the stator winding current of the drive motor is still greater than the maximum current of the drive motor after the gear range of the gearbox is lowered to the first gear, the drive voltage of the drive motor is adjusted by reducing the duty ratio of the drive signal of the drive circuit of the drive motor until the drive voltage is zero and the drive motor stops rotating.

2. The multi-stage automatic speed regulation electric tricycle control system according to claim 1, characterized in that The system further includes a throttle grip; The throttle grip is used to input an operation instruction, and the operation instruction is used to instruct the drive motor and the gear shift motor to perform corresponding operations to change the running speed of the electric tricycle; Wherein, the operating modes of the drive motor include six modes: neutral, low speed, medium speed, high speed, reverse gear, and brake. The gear ranges of the gearbox are divided into neutral and first to fifth gears, corresponding to six positions of the gear shift motor.

3. The multi-stage automatic speed regulation control system for an electric tricycle according to claim 2, wherein, The central controller includes an instruction input module, and the instruction input module is used to detect the rotation angle of the throttle grip, so as to determine the operation instruction according to the rotation angle of the throttle grip and determine the operating mode of the electric tricycle in combination with the gear position switch; the drive module includes the drive circuit of the drive motor and the drive circuit of the gear shift motor; The central controller sends drive signals to the drive circuit of the drive motor and the drive circuit of the gear shift motor respectively according to the operating mode of the electric tricycle, the stator winding current of the drive motor, and the gear position state of the gear shift motor, so as to control the drive motor and the gear shift motor to determine the operating mode of the electric tricycle.

4. The multi-stage automatic speed regulation control system for an electric tricycle according to claim 1, wherein when the operating mode of the electric tricycle is in the medium-speed forward mode, the central controller is specifically configured to send a drive signal to the drive circuit of the gear shift motor to adjust the gear range of the gearbox to the 5th gear, and send a drive signal to the drive circuit of the drive motor to drive the drive motor to operate at half of the base speed; The current detection module continuously detects the stator winding current of the drive motor, and drives the gear shift motor to automatically switch the gear range according to the stator winding current until the operating mode of the electric tricycle changes.

5. The multi-stage automatic speed regulation control system for an electric tricycle according to claim 1, wherein when the operating mode of the electric tricycle is in the low-speed forward mode, the central controller is specifically configured to send a drive signal to the drive circuit of the gear shift motor to adjust the gear range of the gearbox to the 5th gear, and send a drive signal to the drive circuit of the drive motor to drive the drive motor to operate at one-fourth of the base speed; The current detection module continuously detects the stator winding current of the drive motor, and drives the gear shift motor to automatically switch the gear range according to the stator winding current until the operating mode of the electric tricycle changes.

6. The control system of the multi-stage automatically speed-adjustable electric tricycle according to claim 1, wherein, The central controller further includes a speed detection module; the speed detection module is used to detect the speed of the drive motor.

7. The multi-stage automatic speed regulation electric tricycle control system according to claim 1, wherein, The gear shift motor is a permanent magnet brushless DC motor with a power not greater than 50W.

8. A control method for an electric tricycle with multi-stage automatic speed regulation, characterized in that, The method is executed by the multi-stage automatic speed regulation control system for an electric tricycle according to any one of claims 1 to 7, and includes: Step S101, detecting the handlebar state of the electric tricycle to determine the operating mode of the electric tricycle; Step S102, in response to the operating mode being in the high-speed forward mode, determining whether the stator winding current of the drive motor is greater than the maximum current of the drive motor. If so, send a drive signal to the drive circuit of the gear shift motor to drive the gear shift motor to automatically lower the gear range of the gearbox by one gear. If the stator winding current is still greater than the maximum current of the drive motor after lowering the gear range by one gear, drive the gear shift motor to continue to automatically lower the gear range of the gearbox by one gear until the stator winding current meets the requirement of the maximum current of the drive motor; Step S103: In response to the operating mode being in the medium-speed forward mode, send a drive signal to the drive circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a drive signal to the drive motor to drive the drive motor to operate at half of the base speed; continuously detect the stator winding current of the drive motor, and determine whether it exceeds the maximum current of the drive motor based on the stator winding current, so as to drive the gear-shifting motor to automatically perform gear range switching until the operating mode changes; Step S104: In response to the operating mode being in the low-speed forward mode, send a drive signal to the drive circuit of the gear-shifting motor to adjust the gear range of the gearbox to the 5th gear, and send a drive signal to the drive circuit of the drive motor to drive the drive motor to operate at one-fourth of the base speed; continuously detect the stator winding current of the drive motor, and drive the gear-shifting motor to automatically perform gear range switching of the gearbox based on the stator winding current until the operating mode changes.

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