CN104724233A - Directly-driven two-wheeled self-balancing electric vehicle - Google Patents

Abstract

The invention discloses a direct-drive two-wheel self-balancing electric vehicle, which comprises a chassis. A steering rod is installed vertically on the upper part of the chassis. The bottom of the steering rod is connected to a steering potentiometer installed in the chassis. Change the resistance value of the steering potentiometer, the steering potentiometer is connected to the microcontroller through the circuit, the microcontroller is connected to the motor drive module through the circuit, and the motor drive module is connected to the left hub motor and the right hub motor, and the left hub motor and the right hub motor respectively through the circuit The rollers arranged on both sides of the chassis are respectively connected, the microcontroller is connected to the attitude detection module through the circuit, the microcontroller is connected to the wireless communication module through the circuit, the microcontroller is connected to the three-dimensional sensing device through the circuit, and the microcontroller is also connected to the handle through the circuit. The button circuit and liquid crystal display module on the board. The invention has the advantages of simple structure, small volume and low cost.

Description

A direct-drive two-wheel self-balancing electric vehicle

technical field

The invention belongs to the technical field of vehicles and relates to a direct-drive two-wheel self-balancing electric vehicle.

Background technique

With the rapid development of my country's social economy, the process of carization is accelerating, the consumer demand for motor vehicles is gradually strong, and the number of car ownership is soaring. Energy shortage and environmental pollution have become social problems faced by human beings, and traffic jams and car parking problems are also facing severe tests. Therefore, the study of a new type of small, light, energy-saving, convenient and practical, and low-cost intelligent means of transportation will provide a basis for alleviating the problems of high fuel consumption, high energy consumption, large environmental pollution, road traffic congestion, and parking difficulties in my country. an effective solution.

At present, there is a patent related to the direct-drive two-wheel self-balancing electric vehicle: "A Two-wheel Self-balancing Vehicle Driven by a Single Shaft" (CN103600796A), which is characterized in that: the motor fixing frame and the bearing fixing frame are arranged on the car body, The motor is arranged on the motor fixing frame, the motor driving gear is fixedly connected with the motor, the motor driving gear is meshed with the transmission gear, the transmission gear is connected with the transmission shaft, the steering rod is connected with the steering transmission gear, and the steering rack and the wheel steering knuckle are connected to each other. hinged. "A dual-control two-wheel self-balancing smart car" (CN103612695A), is characterized in that: a mechanical structure and a control system installed on the mechanical structure, the control system is operated by hand through both hands or through body coordination The smart car is controlled by the body control operation mode of the activity to realize the smooth operation in the small vertical angle range. "A Variable-Structure Self-Balancing Two-Wheeler" (CN102582738A), is characterized in that the overall structure of the two-wheeler is symmetrical, and consists of four parts: a body device, a driving device, a handlebar device and an electric control device.

The disadvantages of the above invention patents are:

1. Mechanical structure: In the traditional mechanical structure, the wheel bearing is separated from the car body, the mechanical structure is complex, the manufacturing parts are many, and the production cost is high.

2. In terms of control methods: traditional control methods are not flexible, and manual operation or potentiometer adjustment is mostly used, which has low reliability and sensitivity and has great potential safety hazards.

Compared with the prior art, the present invention has the following advantages, such as:

1. The left and right wheels and hubs of the present invention are integrated with 8-inch unilateral shaft brushless motor wheels. Existence: ①The transmission system integrating the transmission shaft and the hub is closed, and the power, transmission and braking devices are integrated into the hub, which simplifies the mechanical part; ②The internal motor directly drives the wheel to rotate. Foreign matter will not enter, and the transmission shaft does not have a chain, so there is no rust or broken chain. It has the advantages of low interference, low driving noise, smooth operation, long life and low maintenance cost. Therefore, the present invention greatly reduces energy consumption, realizes the purpose of low driving noise and light weight of the whole vehicle, and can improve battery life.

2. The control method of the present invention is to use the standing posture of the human body to judge the acceleration, deceleration and steering in the four directions of forward, backward, left and right, and adopts a new capacitive digital gyroscope. Compared with the traditional mechanical gyroscope: ① It is easier to collect data, more convenient to process data, and less signal interference; ② Since the output signal of the mechanical gyroscope is an analog signal, it is necessary to amplify, shape and filter the analog signal, and then the MCU will adjust each The AD conversion of the output of each axis needs to occupy 3 (3-axis output) AD channels, requires an accurate reference source, is greatly affected by temperature, and has high requirements for the RC filter circuit, which affects the design and production of the circuit. The use of digital gyroscopes does not require the use of amplification and shaping filter circuits in circuit design, which makes circuit design simple, high acquisition accuracy, controllable tracking speed, good tolerance to ambient temperature, and can effectively improve the stability of the car body and reduce The self-balancing judgment process of the car body improves the safety and comfort of the passengers.

Contents of the invention

The purpose of the present invention is to provide a direct-drive two-wheel self-balancing electric vehicle, which solves the problems of separation of the wheel bearing and the vehicle body in the existing mechanical structure, complicated mechanical structure, large volume and high production cost.

The technical scheme adopted in the present invention includes a chassis, a steering rod is installed vertically on the upper part of the chassis, the steering rod can be telescopically adjusted in height to suit operators of different heights, the bottom of the steering rod is connected to a steering potentiometer installed in the chassis, and the top of the steering rod There is a handle, the operator holds the handle on the handle to control the steering, turns the handle, changes the resistance value of the steering potentiometer, the steering potentiometer is connected to the microcontroller through the circuit, and the microcontroller is connected to the motor drive module through the circuit, and the motor drive module is respectively The left hub motor and the right hub motor are connected through a circuit, and the microcontroller detects the resistance value of the steering potentiometer, so that the differential speed control of the left hub motor and the right hub motor is realized through the motor drive module, and the left hub motor and the right hub motor The rollers on both sides of the chassis are respectively connected, the microcontroller is connected to the posture detection module through the circuit, the tilt posture of the car body is monitored in real time and the data is sent to the microcontroller for processing, the microcontroller is connected to the wireless communication module through the circuit, wireless communication The module is used for data exchange between the system and the host computer during debugging and operation. The microcontroller is connected to the three-dimensional sensing device through the circuit. The three-dimensional sensing device contains a three-axis gyroscope and a three-axis accelerator. The three-axis gyroscope senses the vehicle body attitude signal It is transmitted to the micro-controller and the acceleration signal of the three-axis accelerator for mixed processing, and the mixed signal is output as the basis for judging the attitude of the car body. The circuit includes buttons S1, S2, and S3. S1 calls the data collected by the current gyroscope, S2 is the data of the rotation of the left and right hubs, S3 is the switch button and the confirmation button. The LCD module is used for data display in conjunction with the button circuit. power supply.

Further, the microcontroller adopts an ECU microcontroller module, and the control chip adopts STM32F103RCT6 produced by ST Company as the core control chip.

Further, the left hub motor and the right hub motor are brushless motors.

Further, the liquid crystal display module is a NOKIA 5110 liquid crystal module.

Further, the posture detection module adopts a capacitive MPU-6050 three-dimensional sensing device.

Further, the model of the wireless communication module is ZigBeeCC2530.

The invention has the advantages of simple structure, small volume and low cost.

Description of drawings

Fig. 1 is a schematic diagram of the front structure of the balance car of the present invention;

Fig. 2 is a schematic diagram of the side structure of the balance car of the present invention;

Fig. 3 is a schematic diagram of the circuit module connection of the balance car of the present invention;

Fig. 4 is a control flow chart of the balance car of the present invention.

In the figure, 1. chassis, 2. steering rod, 3. steering potentiometer, 4. handle, 5. microcontroller, 6. motor drive module, 7. left hub motor, 8. right hub motor, 9. roller, 10. Attitude detection module, 11. ZigBeeCC2530 wireless communication module, 12. Three-dimensional sensing device, 13. Button circuit, 14. Liquid crystal display module, 15. Power supply module.

Detailed ways

The present invention will be described in detail below in combination with specific embodiments.

The structure of the present invention is shown in Figure 1 and Figure 2, and its circuit module connection is shown in Figure 3. The present invention includes a chassis 1, a steering rod 2 is vertically installed on the upper part of the chassis 1, and the steering rod 2 can be telescopically adjusted in height to adapt to different heights For the operator, the bottom of the steering rod 2 is connected to the steering potentiometer 3 installed in the chassis 1, and the top of the steering rod 2 is provided with a handle 4. The operator holds the handle 4 to control the steering, and turns the handle 4 to change the steering potentiometer 3. The steering potentiometer 3 is connected to the microcontroller 5 through the circuit, the microcontroller 5 is connected to the motor drive module 6 through the circuit, the motor drive module 6 is connected to the left wheel hub motor 7 and the right wheel hub motor 8 through the circuit, and the microcontroller 5 Detect the resistance value of the steering potentiometer 3, so that the differential speed control of the left hub motor 7 and the right hub motor 8 is carried out through the motor drive module 6 to realize steering. The left hub motor 7 and the right hub motor 8 are respectively connected and arranged on both sides of the chassis 1 The roller 9 of the microcontroller 5 is connected to the attitude detection module 10 through the circuit, and the tilt attitude of the car body is monitored in real time and the data is sent to the microcontroller 5 for processing. The microcontroller 5 is connected to the wireless communication module 11 through the circuit, and the wireless communication module 11 is used for data exchange between the system and the upper computer during debugging and operation. The microcontroller 5 is connected to the three-dimensional sensing device 12 through a circuit. The three-dimensional sensing device 12 contains a 3-axis gyroscope and a 3-axis accelerator. The 3-axis gyroscope senses the body attitude signal and transmitted to the micro-controller 5 and the acceleration signal of the 3-axis accelerator for mixed processing, and the mixed signal is output as the basis for judging the body attitude. The micro-controller 5 is also connected to the button circuit installed on the handle 4 13 and a liquid crystal display module 14, the button circuit 13 includes buttons S1, S2, S3, S1 calls the data collected by the current gyroscope, S2 is the data about the rotation of the left and right hubs, S3 is a switch button and a confirmation button, and the LCD module 14 is used to cooperate The button circuit 13 performs data display, and the power supply module 15 supplies power to the system.

Among them, the microcontroller 5 adopts the ECU microcontroller module, and the control chip adopts STM32F103RCT6 generated by ST Company as the core control chip. The left hub motor 7 and the right hub motor 8 are brushless motors. The liquid crystal display module 14 is a NOKIA 5110 liquid crystal module. The posture detection module 10 adopts a capacitive MPU-6050 three-dimensional sensing device. The wireless communication module 11 model is ZigBeeCC2530.

Microcontroller 5 adopts ECU microcontroller module, and the control chip adopts STM32F103RCT6 produced by ST Company as the core control chip. The STM32 series is based on the ARM Cortex-M3 specially designed for embedded applications requiring high performance, low cost, and low power consumption. Core, power supply voltage 3.3V, with AD conversion, PWM (Pulse Width Modulation), DMA (Direct Memory Access), UART (Universal Asynchronous Receiver/Transmitter), timer, interrupt and other functional modules, can realize system data transmission and reception through software programming , processing, storage and other operations to meet the control needs of electric vehicles. The highest operating frequency is 72MHz, which can quickly execute the control code and realize faster and more stable control of the self-balancing vehicle. An 8MHz crystal oscillator is connected to the periphery of the chip to ensure that the chip clock is more accurate.

The liquid crystal display module 14 is a NOKIA 5110 liquid crystal module, and the liquid crystal display module 14 is equipped with a 84x48 dot matrix LCD, which can display 4 rows of Chinese characters, and uses a serial interface to communicate with the main processor, and the number of interface signal lines is greatly reduced, including power supply and Eight signal lines including ground. Support a variety of serial communication protocols, the transmission rate is up to 4Mbps, and the display data can be written at full speed without waiting time. The module and the printed board can be connected by conductive glue instead of connecting cables, and the module can be fixed to the printed board with the metal hook on the module, so it is very easy to install and replace. The LCD controller/driver chip is bonded to the LCD die, and the module is small in size. Using low voltage power supply, the working current is below 200μA during normal display, and has a power-down mode.

The posture detection module 10 is used to monitor the tilt posture of the vehicle body in real time. The module uses a capacitive MPU-6050 three-dimensional sensing device, which integrates a 3-axis sensor gyroscope and a 3-axis accelerometer. The MPU-6050's full-scale angular velocity sensing ranges are ±250, ±500, ±1000 and ±2000°/sec(dps), which can accurately track fast and slow motions, and user-programmable accelerometer full-scale sensing Ranges are ±2g, ±4g, ±8g and ±16g. Product transmission can be through I ² C up to 400kHz or SPI up to 20MHz. It transmits the sensed body attitude signal to the ECU microcontroller through the I ² C port for processing. At the same time, the module has a built-in temperature sensor Meter and oscillator with ±1% variation to meet system requirements.

ZigBeeCC2530 wireless communication module 11 is used for data exchange between the system and the upper computer during debugging and running. Zigbee is a low-power personal area network protocol based on the IEEE802.15.4 standard. The technology specified in this agreement is a short-range, low-power wireless communication technology, which is characterized by short-distance, low complexity, self-organization, low power consumption, and high data rate, and is mainly suitable for automatic control and remote control. It can be embedded in various devices, and the communication can be realized simply and conveniently through the UART interface of the ECU microcontroller.

The liquid crystal display module 14 is used for human-computer interaction during the operation of the balance car, so that the driver can clearly understand the current vehicle speed and operation mode.

The motor drive module 6 is used to drive the left and right brushless motors, namely the left hub motor 7 and the right hub motor 8 to rotate normally. Design of motor drive module 6: Since the rotor of the brushless motor is a permanent magnetic steel, it is connected with the output shaft together with the shell, and the stator is a winding coil, and the commutating brush used for alternately changing the electromagnetic field of the brushless motor is removed. When the brushless motor rotates, it relies on changing the alternating frequency and waveform of the current wave input to the stator coil of the motor to form a magnetic field that rotates around the geometric axis of the motor around the winding coil. This magnetic field drives the permanent magnet on the rotor to rotate, thereby Realize the rotation of the motor. The drive circuit of the brushless motor is mainly a bridge drive, through the three-phase bridge circuit, according to a specific timing, the switch tubes Q7~Q12. The design uses the IR2101S driver chip to drive the high-power field effect transistor IRF3205, and the main control chip STM32F103RCT6 outputs the PWM signal to control the on-off of the bridge, so as to achieve the alternating current on the stator coil of the motor, thereby driving the motor. IRF3205 is a high-power field effect transistor with extremely low on-resistance and fast slew rate. The voltage between the drain and source of IRF3205 can reach up to 55V, the gate turn-on voltage is 10V, and the maximum current can be 110A. Since the turn-on voltage of IRF3205 needs to reach 10V, the project uses IR2101S to drive. Through its bootstrap boost circuit, the control voltage can reach more than 10V, and the bridge can be normally turned on and off according to the input signal of STM32F103RCT6 to achieve the purpose of driving the brushless motor. . Fig. 4 is the software control flow of the present invention.

The electric vehicle of the present invention has the advantages of adopting a novel capacitive digital gyroscope. Compared with the traditional mechanical gyroscope, the collected data is more stable and reliable, the data processing is more convenient, the signal interference is smaller, the circuit design is simple, the collection accuracy is high, the tracking speed is controllable, the environmental temperature tolerance is good, and the car body can be effectively improved. It reduces the judgment of self-balancing during the start-up process of the car body, and improves the safety and comfort of the passengers. The left and right wheels and hubs of the present invention are integrated with 8 inches of unilateral shaft brushless motor wheels. The problems of complex mechanical structure and complex automatic intelligent control of the existing invention are solved, and the appearance is more concise and elegant. The present invention adopts lithium battery to supply power. Lithium batteries have the advantages of high storage energy density, light weight, relatively long service life, low self-discharge rate, no memory effect, strong high and low temperature adaptability, and environmental protection, which can increase battery life and reduce carbon emissions.

At the same time, the present invention is a small, light, energy-saving, convenient and practical, and low-cost intelligent transportation tool, which can alleviate the problems of large fuel consumption, high energy consumption, large environmental pollution, road traffic congestion, and parking difficulties in my country. . The car uses electric energy as the power source, and has two wheels side by side. It is a small, light, energy-saving, convenient and practical, and low-cost intelligent transportation tool. , road traffic congestion, parking difficulties and other issues to provide an effective solution.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Any simple modifications made to the above embodiments according to the technical essence of the present invention, equivalent changes and modifications, all belong to this invention. within the scope of the technical solution of the invention.

Claims (6)

1. a direct-driving type double-wheel self-balancing battery-driven car, it is characterized in that: comprise chassis (1), chassis (1) upper vertical is provided with deflecting bar (2), deflecting bar (2) can stretch adjustment highly, to adapt to the operating personal of differing heights, deflecting bar (2) bottom is mounted on and turns to potential device (3) in chassis (1), deflecting bar (2) top is provided with handle (4), operating personal is held and carry out course changing control on handle (4), swing handle (4), change the resistance value turning to potential device (3), potential device (3) is turned to connect microcontroller (5) by circuit, microcontroller (5) connects motor drive module (6) by circuit, motor drive module (6) connects left wheel hub motor (7) and right wheel hub motor (8) respectively by circuit, microcontroller (5) detects the resistance value size turning to potential device (3), thus by motor drive module (6) to left wheel hub motor (7) and right wheel hub motor (8) carry out differential control realization turn to, left wheel hub motor (7) and right wheel hub motor (8) are connected the roller (9) being arranged on chassis (1) both sides respectively, microcontroller (5) connects attitude detection module (10) by circuit, the lateral attitude of Real-Time Monitoring car body also sends the data to microcontroller (5) and processes, microcontroller (5) connects wireless communication module (11) by circuit, wireless communication module (11) for system in commissioning process with the data exchange of upper computer, microcontroller (5) connects three-dimensional sensing device (12) by circuit, three-dimensional sensing device (12) inside comprises three-axis gyroscope and three axle accelerators, (3) axle gyroscope senses vehicle body attitude signal and is transferred to microcontroller (5) and carries out mixed processing with the Acceleration Signal of three axle accelerators, export the foundation that mixed signal judges as vehicle body attitude, microcontroller (5) is also mounted on key circuit (13) on handle (4) and LCD MODULE (14) by circuit, key circuit (13) comprises button S1, S2, S3, S1 calls the data that current gyro gathers, S2 is the data of left and right hub rotation, S3 is switching key and confirms button, LCD MODULE (14) carries out data display for coordinating key circuit (13), power module (15) is powered to system.

2. according to direct-driving type double-wheel self-balancing battery-driven car a kind of described in claim 1, it is characterized in that: described microcontroller (5) adopts ECU micro controller module, control chip is that the STM32F103RCT6 of ST company generation is as kernel control chip.

3. according to direct-driving type double-wheel self-balancing battery-driven car a kind of described in claim 1, it is characterized in that: described left wheel hub motor (7) and right wheel hub motor (8) are brushless motor.

4. according to direct-driving type double-wheel self-balancing battery-driven car a kind of described in claim 1, it is characterized in that: described LCD MODULE (14) is NOKIA 5110 Liquid Crystal Module.

5. according to direct-driving type double-wheel self-balancing battery-driven car a kind of described in claim 1, it is characterized in that: described attitude detection module (10) adopts the three-dimensional sensing device of condenser MPU-6050.

6., according to direct-driving type double-wheel self-balancing battery-driven car a kind of described in claim 1, it is characterized in that: described wireless communication module (11) model is ZigBeeCC2530.