treadmill automation and physiological control

8/3/2019 Treadmill Automation and Physiological Control

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Treadmill Automation and

Physiological Control systems

OO Ajayi


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Introduction:Background

Rehabilitation therapy is required forneurological impairment

Types of rehabilitation therapy:treadmill rehabilitation

mechatronics

robotic devices,....

Treadmill is used in rehabilitationtherapy-by the healthy and disabled people toenhance fitness, walking, balancing and for retraining,...


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ForSpinal Cord Injured (SCI)

patients (complete &incomplete)

Stroke

Paraplegia

Hemilegia

Requires

two or more physiotherapists

effort + time =costs

RehabilitationTherapy

Introduction:Treadmill Automation


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Treadmill has walking surfacelimitationand this could lead to tripping andfalling,...

balancing problem

safety concerns


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Research

works(TreadmillAutomation)

Mostly in virtual environment

Omni-Directional Treadmill

(Darken and Cockayne, 1997)Sarcos Treadport

(Christensen et al., 1998)

ATLAS System

(Noma and Miyasato, 1998)

impracticable and unhealthy for disabled people



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Omni-Directional Sarcos Treadport

ATLAS System



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Control is common in all physiologicalsystems

Physiological control systems are

implemented-by the interaction of various organsthrough processes and functions in living systems in order tomaintain an equilibrium position

Physiological control systems detects

detect changes

initiate certain changes

prevent dangers

Introduction:Physiological Control Systems


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Forfitness improvement, &

therapeutic innovations

However

limited research on

controlling HR, O2uptake

Physiologicalcontrolsystems



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Research

works(Physiological

Control Systems)

Mostly on HR

HR controlled ergometer

(Jacobsen & Johansen, 1974)Self-biofeedback HR control

(Sada et al. ,1999)

Servo-controlled HR

(Kawada et al., 1999 )

HR control equipment are generally slow



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Introduction:

Goals/Objectives

1. To present a new approach to treadmillautomation and physiological control systems

(serves as a platform for rehabilitation therapy)

2. Experimentally develop models for feedbackcontrollers

3. Implement controllers in real-time to validatesimulation results


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Methodology

Approach is based on Model-Based FeedbackControl System.

Modelling.Identify models from series of experiments

using the treadmill (open-loop).

Control Design.Use the models to design feedback controllers(closed-loop).

Plant*speedSpeed,HR,

Speed,HR,

speedPlant*controller

_

desired

Speed/HR


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Methodology:Experimental set-up

ApparatusTreadmill-Tunturi G300

Ultrasonic range sensor(Polaroid 6500 series)

Polar Heart Rate Monitor(transmitter belt)

PC- Matlab/Simulink,C++, Humusoft Real-timetoolbox, Digital I/O &counter/timer board, serialinterface (RS-232)


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TreadmillAutomation

Physiological Control

Systems

Results:Modelling

Modelling and Identification

0 200 400 600 800 1000 120050

100

150

200

HR

[bpm]

Input and output signals

0 200 400 600 800 1000 12000

1000

2000

3000

Time [sec]

Speed[mm/s]

0 20 40 60 80 100 120 140 160 180 200-2000

-1000

0

1000

Speed[mm/s]

Input and output signals

0 20 40 60 80 100 120 140 160 180 200-100

0

100

200

300

400

500

Time [sec]

Speed[mm/s]


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Results:Speed Controller

0 20 40 60 80 100 120 140 160 180 2000

200

400

600

800

1000

1200

1400

1600

Time [sec]

Speed[mm/s]

Measured speed

PRBS input signal

0 20 40 60 80 100 120 140 160 180 2000

200

400

600

800

1000

1200

1400

1600

Time [sec]

Speed[mm/s]

Measured speed

PRBS reference signal

No load On load

Tracking Response


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Results:Speed Controller

0 20 40 60 80 100 120 140 160 180 2000

200

400

600

800

1000

1200

1400

1600

1800

Time [sec]

Speed[mm/s]

Measured speed


0 20 40 60 80 100 120 140 160 180 2000

200

400

600

800

1000

1200

1400

1600

Time [sec]

Speed[mm/s]

Control signal


Abruptly jumping on and off the treadmill

Disturbance Rejection


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Results:Heart Rate Controller

0 50 100 150 200 250 30070

80

90

100

110

120

130

140

150

160

Time [sec]

HR[bpm]

Reference signal

Measured HR

Tracking Response

Series of square load test Constant load test

0 200 400 600 800 1000 120060

70

80

90

100

110

120

130

140

150

Time [s]

HR[bpm]

Reference signal

Measured HR


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Discussion

Models Capability-Demonstrated that a simple ARX model can beused to model the dynamics of the treadmill andHR from measured input-output open-loop data.

Speed Controller Capability-The speed controller has the capacity to rejectdisturbances.

HR Controller Capability-

The HR controller was designed from one of thesubjects model and implemented on othersubjects. This indicates that the controller isrelatively robust and caters for individual(inter/intra individual) differences.


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Conclusion =FeasibilityLimitations, Potentials...

Treadmill Automation

Speed Tracking

performancesatisfactory.

Hardware limitations

affects theperformance of ourposition controller.

Physiological Control

Systems

Good HR Trackingperformance achieved.

Accurate real-time

control of oxygenuptake duringmoderate treadmillexercise has beenachieved.

treadmill automation and physiological control

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