BananaBot is a kind of five-link dual-wheel balancing robot. It's based on balancing infantry robot in the RoboMaster competition.
BananaBot is a graduate design of Dalian University of Technology.
BananaBot has three main components: the body-box, the legs, and the wheels. The structural design and kinematic model derivation are both based on this.
Here lists more paramaters about robot:
| Parameter Name | Value | Unit |
|---|---|---|
| Mass | 3.9 | kg |
| Maximum Load | 2.5 | kg |
| Maximum Acceleration | 1.0 | m/s² |
| Maximum Linear Velocity | 1.2 | m/s |
| Maximum Jump Height | 0.2 | m |
| Shortest Effective Pendulum Length | 0.12 | m |
| Longest Effective Pendulum Length | 0.32 | m |
| Maximum Left-Right Pendulum Height Difference | 0.15 | m |
| Endurance Time | 1.0 | h |
Here is the hardware connection of BananaBot:
The build of the kinematic model is based on this paper1. The robot is approximated as an inverted pendulum model composed of a body-box, a rigid pendulum rod, and wheels. And we construct the rotational and translational kinematic equations for this system.
The system state variables are defined as: [ \mathbf{x} = [\theta, \dot{\theta}, x, \dot{x}, \phi, \dot{\phi}] \quad (3.10) ]
The system output variables are defined as: [ \mathbf{u} = [T, T_p] \quad (3.11) ]
Simplify using MATLAB symbolic computation and linearize around the equilibrium point. This content can be found in the MATLAB folder, as LQRModule.m.
We have the following main controllers:
- LQR Controller
- Equivalent Pendulum Length Controller
- Fork Controller
- Heading Angle Controller
- Roll Angle Controller
As well as the following observers:
- Body Attitude EKF (Extended Kalman Filter)
- Anti-skid KF (Kalman Filter)
And the transformation:
- VMC Transformation
Among them, the VMC (Virtual Model Control) controller utilizes the statics of a five-bar linkage to achieve bidirectional force mapping between the pendulum and the motors.
- Code generator: STM32CubeMX-6.11.1
- Tools chains: arm-none-eabi-gcc
- Debugger: OpenOCD + GDB(Windows need mingw64)
- STM32CubeH7 Firmware Package V1.11.0 / 04-Nov-2022
- STM32CubeExpansion_AZRTOS-H7 V3.2.0
- OneMessage - Message System
- WHX EKF - AHRS
Software construction list here:
USB and Mavlink haven't been fitted in this version of codes.
Real codes may not 100% fit this picture.
BTW, LVGL files in this project are useless.
Footnotes
-
陈阳, 王洪玺, 张兰勇. 轮腿式平衡机器人控制[J]. 信息与控制, 2023, 52(05): 648-659. https://doi.org/10.13976/j.cnki.xk.2023.2533. ↩