Parameters &

Observations

Level 1: Patients Level 2:

Physicians

User Level

Level 3: Developer

User Level

Level 1: Patients Level 2:

Physicians

Level 3: Developer

Use MobileEyes

Change parameters using MobileEyes.

MobileEyes screens the parameter, depending on the type of user.

All values are recorded in millimeter and second

To access the parameters that have any significant change in the behavior of the chair, the Parameter

Priority has to be set to Expert.

The Higher Parameters

Quite fast. Work with speed/velocity parameters

Starts and ends with a jerk.

Turning (especially through a small angle) is not smooth.

Does not go through doorways.

Almost runs into obstacles, before coming to a stop.

Perhaps parameters for rotation?

Padding parameters

Padding parameters

Main Concerns

Perhaps parameters for acceleration?

Each Drive Mode has a different set of parameters e.g.

Changing parameter in one list, has no effect on the parameters of the other list, even though the parameters may have the same name.

Parameter Lists

Parameter list – Express Drive

Robot Config - a short list of speed related parameters.

Path Planning Setting - full list of parameter for Smart Drive.

Parameter list - Smart Drive

• TeleOp Settings - full list of parameter for Smart Drive

List of Modified Parameters

MaxVelTransAccel TransDecel

SideClearanceAtSlowSpeedFrontPaddingAtSlowSpeedFrontPaddingAtFastSpeed

ForwardSideClearanceAtSlowSpeed

Procedural Standards

Did test trials: Number of test trials ranged from 6 to 15.

All test trials were done over a distance of 20ft.

When testing each parameter:

simulate a hospital setting.

judged from a patient’s point of view.

MaxVel Controls the speed of the chair directly.

• In Express Drive: MaxVel = 600

On average 8.3sec to cover a distance of 20ft.

• In Smart Drive: MaxVel = 900

On average 8.6sec to cover a distance of 20ft.

TransAccelIncreasing the value, decreases the time taken by

the wheelchair to reach maximum speed.

• In ExpressMode:TransAccel = 425

Lower value results in jerkier start.

Slows down the wheelchair.Braking distance is 1.5m.

• In Express Mode:TransDecel = 175

If TransDecel < 175, stops smoothly but overshoots goal.

TransDecel

TransDecelOvershooting the Goal

Side Padding Any object at this specified distance from its side,

is considered an obstacle.

• In Express Drive:SideClearanceAtSlowSpeed = 50

• In Smart Drive:ForwardSideClearanceAtSlowSpeed = 25

Both values set to allow the wheelchair to go through door ways.

Front PaddingAny object at this specified distance from its

front, is considered an obstacle.

• In Express Drive:FrontPaddingAtSlowSpeed = 300Applies when speed < than MaxVel.

FrontPaddingAtFastSpeed = =500Applies only if speed of wheelchair is at

maximum.

Results

Starting and ending are smoother.

Speed is comfortable.

Can go through door ways which are at least 33.5 inches (851mm) wide.

Stops at a safe distance from the obstacle.

Turning is smoother than before but still a bit jerky.

Challenges

Overcoming the fear of making changes.

Could not figure out a way to measure the effect of RotVelMax.

Questions?