Parallel-arm quadruped robot dog

Detailed project video link: https://www.bilibili.com/video/BV1V7421R712/?spm_id_from=333.999.0.0
Hardware Design
: Microcontroller: STM32F103C8T6
Power Supply: 7.4V-12V input, 5V output from XL4005E1 to power the servo, and 3.3V output from RT9013 to power the microcontroller
Communication: NRF24L01
Servo Driver: Option 1: Directly generate 8-channel PWM output through 2 timers; Option 2: Communicate with PCA9685 via IIC to drive the servo.
Program Design Highlights:

Generate cycloidal equations and foot trajectory planning:
sigma=2pi(t-t_T)/(faaiTs);
Xep=((xf-xs)(sigma-(sin(sigma))))/(2pi)+xs;
Zep = h(1-cos(sigma))/2;
Inverse kinematics (cosine theorem, Pythagorean theorem).

A and B are the output axes of the two servo motors, and they are 2a apart. The foot coordinates (x, y) are derived from trajectory planning. L1 and L2 are the arm lengths of the upper and lower arms of the leg.
θ1 and θ2 are the servo motor rotation angles we need to solve for.
Since θ1 = 90° - (β - γ), the solution order is: L3 → β → γ.

Use MPU6050 sensor feedback data to implement attitude control

. Note :

Before assembling the servo motor, download the servo motor return-to-center program, that is, comment out this part in main.c, as shown in the figure.


Note the servo motor pin assignment: FR-front → A6, FR-rear → A7; BR-front → B0, BR-rear → B1; BL-front → B8, BL-rear → B9; FL-front → B6, FL-rear → B7.
More detailed tutorials will follow... to be continued.