All projects
02 / Aug 2022/ Smart India Hackathon, KCG College of Technology
Smart Knee Actuator
Passive knee braces cannot help post-stroke patients at the moment in the gait cycle when the knee needs support.
- Role
- Firmware, electrical and fluid-power design, bench commissioning.
- Stack
- Embedded C, RP2040, TinyML, I2C / BLE, Pneumatics
- Patent
- Indian Patent Application No. 202341027059, published Oct 2024
01
What I built
- 01A powered knee brace that detects the walking phase and fires a pneumatic cylinder to assist the knee, with no manual input.
- 02Bare-metal C firmware on an RP2040 samples an MPU6050 IMU over I2C and flex sensors over ADC, runs an on-device TinyML gait-phase classifier, and drives solenoid-operated 5/2 directional control valves through GPIO.
- 03BLE telemetry for live monitoring.
02
Hardware
- 01RP2040, dual-core ARM Cortex-M0+
- 02MPU6050 IMU (I2C), flex sensor (ADC)
- 035/2 solenoid-operated DCV, double-acting cylinder, FRL unit, 10 bar supply
- 04Li-Po pack with LM2596 buck rail, wiring harness
03
Software
- 01Embedded C
- 02TinyML gait-phase classifier
- 03BLE telemetry
- 04FEA
04
Validation
- 01FEA of the frame under a 500 N load in extension and flexion; a 60 kg user needs under 300 N.
- 02Commissioned on the bench with oscilloscope and DMM, root-causing actuation timing, pressure regulation and sensor calibration faults.
05
Results
- 01Working prototype built for Smart India Hackathon.
- 02Indian patent application 202341027059, published October 2024.
06
Characteristics
| Parameter | Value |
|---|---|
| MCU | RP2040, Cortex-M0+, 264 KB SRAM |
| Sensing | MPU6050 over I2C, flex over ADC |
| Pneumatic supply | 10 bar with FRL unit |
| Actuator | Double-acting cylinder, 5/2 DCV |
| FEA load case | 500 N |
| Power | Li-Po + LM2596 buck |
Links
07
Gallery
