Embedded Motion Control 2015 Group 3/Experiments

Experiments

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Experiment 1

Date: Friday May 8

Purpose:

• Working with PICO
• Some calibration to check odometry and LRF data

Evaluation:

• There were problems between the laptop we used and PICO.

Experiment 2

Date: Tuesday May 12

Purpose:

• Calibration
• Do corridor challenge

Calibration:

In the lectures, the claim was made that 'the odometry data is not reliable'. We decided to quantify the errors in the robot's sensors in some way. The robot was programmed to drive back and forth in front of a wall. At every time instance, it would also collect odometry data and laser data. The laser data point that was straight in front of the robot was compared to the odometry data, i.e. the driven distance is compared to the measured distance to the wall in front of the robot. The following figure is the result:

Difference between odometry and LRF

The starting distance from the wall is substracted from the laser data signal. Then, the sign is flipped so that the laser data should match the odometry exactly, if the sensors would provide perfect data. Two things are now notable from this figure:

• The laserdata and the odometry data do not return exactly the same values.
• The odometry seems to produce no noise at all.

The noisy signal that was returned by the laser is presented in the next figure. Here, a part of the laser data is picked from a robot that was not moving.

Static LRF

• The maximum amplitude of the noise is roughly 12 cm.
• The standard deviation of the noise is roughly 5.5 mm
• The laser produces a noisy signal. Do not trust one measurement but take the average over time instead.
• The odometry produces no notable noise at all, but it has a significant drift as the driven distance increases. Usage is recommended only for smaller distances (<1 m)

• Driving through a straight corridor went very well. But we could not succeed the corridor challenge yet.

Experiment 3

Date: Tuesday May 22

Purpose:

• Calibration
• Do corridor challenge

Evaluation:

• Combining the Scan and Drive for path planning was not succesfull.
• Potential field script was not ready yet.

Experiment 4

Date: Tuesday May 29

Purpose:

• Test potential field
• Test path planning

Evaluation:

• Path planning was not very succesfull.
• Potential field did very well in corridors (see video). Intersections need some extra attention.

Experiment 5

Date: Friday June 05 (9.45 am)

Purpose:

• Test potential field & decision intergration

Evaluation:

• Integration is almost done. Still has some problems with crossing intersection and taking corners into (short) dead ends like doors.
• The collision detection behaves somewhat unexpected some times.

Experiment 6

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Purpose:

Evaluation: ..

Experiment 7

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Evaluation: ..