Adaptive Knee Joint Control for an Active Amputee Prosthesis

Apresentação em tema: "Adaptive Knee Joint Control for an Active Amputee Prosthesis"— Transcrição da apresentação:

1 Adaptive Knee Joint Control for an Active Amputee Prosthesis
5th Latin American Robotics Symposium – LARS 2008 Salvador, October 29 – 30, 2008 Adaptive Knee Joint Control for an Active Amputee Prosthesis Glauco Garcia Scandaroli, Geovany Araújo Borges, Adson Ferreira da Rocha, and Francisco Assis de Oliveira Nascimento s: Laboratório de Robótica e Automação (LARA)‏ Grupo de Robótica, Automação e Visão Computacional (GRAV)‏ Departamento de Eng. Elétrica - Universidade de Brasília (UnB)‏ 1 1

2 Outline of the presentation
Introduction; Prosthesis Description; System Modeling; Control Strategies; Conclusions & Ongoing Work. 2 2

3 Introduction Rehabilitation robotics:
Restoring lost motor functions; Supporting treatment. Importance of knee in locomotion. Active or Passive knee? Three DOF Prosthesis: More similar to human leg.

4 Prosthesis Description
Thee DOF: Knee (3R15 Otto Bock): Sagittal Plane. Foot: Sagittal Plane; Frontal Plane. Actuators: Servo-Amplifiers + DC Motors. Movements: EMG Signals – Knee; Predictive Model – Foot: Gyrometers + IR.

5 System Modeling Simplified Model based on Free Body Diagram.
Discrete non-linear model: Variable change: Finally:

6 System Modeling Parameter Identification: Batch Least Squares.
Second order approach: First order approach:

7 System Modeling Parameter Identification: Batch Least Squares.
Second order approach: First order approach:

8 . Control Strategies PID Control:
Root-Locus Tuned; Experimentally Tuned. Model Reference Adaptive Control (MRAC). φref . ia,k ia φ controller ν (φk)‏ DAC plant ADC potentiometer

9 Control Strategies PID – Root Locus Tuned:
Kp = , Ki = 0.06, Kd = , CL Poles: s1 = -4.89, s2 = Rise time: 650 ms.

10 Control Strategies PID – Root Locus Tuned:
Kp = , Ki = 0.06, Kd = , CL Poles: s1 = -4.89, s2 =

11 Control Strategies PID – Experimentally Tuned:
Kp = 0.1, Ki = 0.111, Kd = ,

12 Control Strategies PID – Experimentally Tuned:
Kp = 0.1, Ki = 0.111, Kd = ,

13 Control Strategies MRAC: Characteristics of reference model:
First order; Rise time: 300 ms, Null steady-state error. Parameters: θ1 = ; θ2 = ; γ = 1/3.

14 Control Strategies MRAC: Characteristics of reference model:
First order; Rise time: 300 ms, Null steady-state error. Parameters: θ1 = ; θ2 = ; γ = 1/3.

15 Control Strategies MRAC: Characteristics of reference model:
First order; Rise time: 300 ms, Null steady-state error. Parameters: θ1 = ; θ2 = ; γ = 1/3.

16 Conclusions & ongoing work
System Modeling: First order approximation → No transitory losses. Control Strategies: PID Root-Locus → Steady-state error; PID Experimental → Oscillation, MRAC → Small oscillation. Ongoing work: Control of foot joints; EMG Integration.

17 Questions?

18 Thank you for your attention!