LeTian-robot2 (wheel-legged robot)

 
1. The source of the project
   is LeTian-robot2 (wheel-leg robot). The inspiration of the project comes from the Ascento robot. The original intention of the design is to learn the control algorithm and realize the final jumping function through the production of the wheel-leg robot. Due to the huge theoretical knowledge of the entire system and the limited ability, the theoretical design, modeling simulation, and physical simulation of the jumping function have not been realized yet. It is expected to be realized before June next year. The functions currently realized include automatic self-balancing, height adjustment, and wireless control. Since ESP32S3 supports offline voice recognition, offline voice recognition will be added to this project in the next step. Offline voice development only supports the ESP-IDF platform.
 
2. The project attribute
  structure design reference is the Ascento robot. The PCB, schematic diagram, 3D model, BOM table, etc. are completely open source.
 
3. Hardware part
   The circuit part of this design was completed by the professional version of LiChuang EDA. CAD and Solidworks were used for drawing.
(1) Supported chip: ESP32-S3-WROOM-1-N8
(2) Pinout: two servo interfaces, two brushless motor interfaces, two IIC interfaces, and four SPI interfaces.
(3) The onboard MPU6050 is designed to be 48*48mm in length and width, and is compact in size.
(4) DRV8313 is used as the driver chip with a peak current of 2.5A. The drive motor can only be a pan/tilt motor (phase resistance is about 10 ohms). (
5) Two servo interfaces, using the XH2.54 3P interface
. (6) ESP32 integrates a one-key download circuit, uses the CH340K serial port chip, and uses the typec interface to communicate with the computer and download programs. (7) ESP32 reserves IO 0 button and RST reset button. (8) Two FPC 0.5mm 8P LCD interfaces are reserved, which can control two 1.28-inch round screens. (9) LM2596 is used as a 5V voltage regulator to power the servos. (10) The power input can use XT60 input, and the power supply uses a 3S lithium battery . 4. Hardware selection                                                                    4010 motor                                                   wheel (directly interference fit with the motor)                                                             servo 5. PCB version (all PCBs are drawn using EasyEDA professional version) V2.0                                                front                                                          and back V2.0 PCB version uses a 3-layer connection method, the main control and the motor drive main control are separated, the motor drive is driven by L6234D, and the motor power supply uses a dual-channel boost chip for separate power supply, which is costly and should not be used. V3.0 (Final Version) (Unfortunately, due to the epidemic, the SMT V3.0 board has been lying in the Cainiao Station and cannot be obtained in a short time. Temporarily, the V2.0 master control and power layer + 4010 motor are used for control. Due to the problem of the left wheel motor, the final control effect is not good. The latest 3.0 version program will be updated after the epidemic improves)                         Master control layer (Note: Please use a wire to connect the back VCC)                                    Power layer (lead out the servo and motor interface)                                 Encoder (AS5600 chip) 4010 MOTOR single-channel simpleFOC control board (reserved serial port 0 communication) 6. Software implementation     Due to the epidemic, the V3.0 version of the PCB cannot be obtained. The hardware version temporarily uses the V2.0 version of the master control + power layer + 4010 motor drive. Therefore, this version of the motor drive is separated from the master control code and is implemented in different master controls. The V3.0 version of the motor drive is fully integrated and completed by an ESP32S3. When the subsequent epidemic improves, the 3.0 version of the code will be debugged.    Code development platform: VScode platformHardware      structureThe    motor drive is implemented using the SimpleFOC algorithm, and the motor runs in torque mode. The main control and motor driver use serial communication to give the target value and read the speed and angle values. The motor is initialized for the first time motor.initFOC(); Delete the parameters in the function, wait for the motor to be powered on, and then fill in the motor direction and deviation angle output by the serial port. Skip the motor self-test next time it is powered on. The main control runs ESP32 RTOS and creates two tasks: serial control of the motor and reading the motor angle information. At the same time, Blinker APP can be used to control it using Bluetooth. Read wheel speed information, MPU6050 information, and perform PID calculations. Give the motor torque value through serial communication, run blinker for Bluetooth control, and update the angles of the servos on both sides at the same time. PID parameter adjustment Blinker APP Due to time and epidemic reasons, the mechanical structure and algorithm will continue to be optimized in the future, stability and anti-interference will be improved, and more functions will be added. At present, self-balancing, height control and tilt angle control have been realized. The next step will be to achieve balance in complex terrain and develop code writing and debugging under the ESPIDF environment. Reference links: https://www.bilibili.com/video/BV15W4y1H7Kb/?spm_id_from=333.999.0.0&vd_source=fa8c62cf1b1a4771b713149461b59df7 https://www.bilibili.com/video/BV15L411b7mH/?spm_id_from=333.337.search-card.all.click&vd_source=fa8c62cf1b1a4771b713149461b59df7 https://www.youtube.com/watch?v=f9GJqqUpL2w All PCBs, schematics, 3D models, and BOM lists are open source. Please like, collect and forward them, and you can also discuss them in the comment area.