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CPS now compute from a difference of position the 2D speed of cars. The reason I implemented this is because the encoder of car 2 (which is now fixed) was not working and I needed to measure its speed. I made a test to see if this new measurement was reliable. I run car2 with fixed steer and PWM and I compared the speed measured by the encoder and the CPS. in a circle whose diameter I manually measured to be about 200cm. The car completed 5 circles.
Results are in figure speed_cps_encoder.png. The left one is the raw speed, in the right one peaks are removed and the CPS speed is filtered with a average filter window (the window width is 5). The manually computed average speed is 835.66 mm/s, the encoder average speed is 857.69 mm/s and the cps average speed is 895.65 mm/s. In order for the encoder to be the real average speed, the actual diameter should be 5.4 cm greater. In case of the CPS one it should be 14.4cm greater which is less likely.
Few observations:
- peaks in CPS speed are likely to be caused by position leaps between cameras;
- CPS speed average is above the one measured with the encoder.
CAR MODEL
EFFECT OF PWM AND STEER INPUT ON THE SPEED DYNAMICS
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