rezeck
commented
1 year ago Hey @jacobh2299,
Sorry again for the late reply.
It seems to me that the laser is not working properly. In the second figure, the ranges field should be a value close to range_min. The ranges field contains the distance (in meters) for 16 IR sensors. We interpolate these 16 IR sensors (blue) from the 8 real IR sensors (red) on the robot. The field intensities are the light intensity (0-1023) received by the photodiode minus the ambient light intensity. That is, it would be the intensity of light returned after reflecting on an object. The correspondence IR sensor and the position in the robot are given in the following.
This is a video of expected behavior.
In your case, it may be a problem due to a lack of calibration or hardware failure. Please, test the two procedures below and let me know if they worked for you.
Calibration
To calibrate the 8 IR sensors, use the launch file hero_confmode.launch, and the ros service /hero_*/ir_calibration.
The calibration process is done as follows:
1) place an object (preferably white color) at a known distance (d) from one of the IR sensors you want to calibrate;
2) Use the laser topic rostopic echo \hero_*\laser to see the intensity for that sensor;
3) The calibration parameter is obtained by the equation (intensity) * d^2.
4) Repeat this procedure for all sensors and save these 8 values;
5) With the 8 calibration values in hand, run the calibration service:
rosservice call /hero_*/ir_calibration "{IR0: 0.39, IR1: 0.28, IR2: 0.45, IR3: 0.29, IR4: 0.52, IR5: 0.22, IR6: 0.23, IR7: 0.28}"I am still improving this process and the following is an alternative.
You must place 8 objects at the same distance from the 8 IR sensors.
I created a 3d printer part to help with this setup.
After placing the objects, run the script:
rosrun hero_examples hero_ir_calib.py hero_*This is a video showing how to execute this script.
IR Sensor Test If you still don't have any luck, proceed with this process to see if everything is ok with the hardware. Try burning the RangeSensor firmware, and check the output for consistency. Maybe it has an IR sensor soldered upside down. This is a video showing how to proceed with this test.
Please let me know if everything works out. I'm still trying to refine and automate this sensor and actuator calibration step. As soon as I finish this, I will update the tutorial.
Edit 1.0 I just committed some files in the noetic-devel repository. If you find some scripts missing, try to sync with this current commit.
Best, Rezeck
jacobh2299
Hello! I am working with a research lab that has manufactured 5 of your Hero 2.6 robots. We seem to have run into a few issues when it comes to running the example code that you have provided in your github. While trying to run the random.launch python script, our robot only rotates clock-wise. I have a few screenshots of the rostopic laser that was provided of our IRs while uncovered and while covered. Our understanding is that the IRs should be defaulted to 0.5, but it appears that they are not defaulting to that very well. The first image is of the IRs uncovered, while the second image is of the IRs covered. If you could help us understand what we are looking at in the laser rostopic or help explain the random.launch script that you had written I think it would help our debugging process run a bit quicker:
Uncovered IRs:
Covered IRs:
Note that we changed the python script for random.launch to use python3 as we were getting errors regarding Yaml while only using Python 2.x. Changing to python3 resolved the crash issue, but the bot still only rotates clock-wise while running the script.
Thanks! University of Utah Research Team