1 glauco garcia scandaroli, geovany araújo borges, adson ferreira da rocha, and francisco assis de...
TRANSCRIPT
1
Glauco Garcia Scandaroli, Geovany Araújo Borges, Adson Ferreira da Rocha, and
Francisco Assis de Oliveira Nascimentoe-mails: [email protected], [email protected],
[email protected], [email protected].
Adaptive Knee Joint Control for anActive Amputee Prosthesis
5th Latin American Robotics Symposium – LARS 2008Salvador, October 29 – 30, 2008
Laboratório de Robótica e Automação (LARA)Grupo de Robótica, Automação e Visão Computacional (GRAV)Departamento de Eng. Elétrica - Universidade de Brasília (UnB)
2
Outline of the presentation Introduction;
Prosthesis Description;
System Modeling;
Control Strategies;
Conclusions & Ongoing Work.
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.
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.
System Modeling Simplified Model based on Free Body Diagram.
Discrete non-linear model:
Variable change:
Finally:
System Modeling Parameter Identification:
Batch Least Squares. Second order approach:
First order approach:
System Modeling Parameter Identification:
Batch Least Squares. Second order approach:
First order approach:
Control Strategies
ia,kcontroller ν (φk)
ADC potentiometer
φref
PID Control: Root-Locus Tuned; Experimentally Tuned.
Model Reference Adaptive Control (MRAC).
DAC .ia plantφ
Control Strategies PID – Root Locus Tuned:
Kp = 0.0624, Ki = 0.06, Kd = 0.0024, CL Poles:
s1 = -4.89, s2 = -0.9917. Rise time: 650 ms.
Control Strategies PID – Root Locus Tuned:
Kp = 0.0624, Ki = 0.06, Kd = 0.0024, CL Poles:
s1 = -4.89, s2 = -0.9917.
Control Strategies PID – Experimentally Tuned:
Kp = 0.1, Ki = 0.111, Kd = 0.0011,
Control Strategies PID – Experimentally Tuned:
Kp = 0.1, Ki = 0.111, Kd = 0.0011,
Control Strategies MRAC:
Characteristics of reference model: First order; Rise time: 300 ms, Null steady-state error.
Parameters: θ1 = 0.099481; θ2 = 0.089133; γ = 1/3.
Control Strategies MRAC:
Characteristics of reference model: First order; Rise time: 300 ms, Null steady-state error.
Parameters: θ1 = 0.099481; θ2 = 0.089133; γ = 1/3.
Control Strategies MRAC:
Characteristics of reference model: First order; Rise time: 300 ms, Null steady-state error.
Parameters: θ1 = 0.099481; θ2 = 0.089133; γ = 1/3.
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.
Questions?
Thank you for your attention!