i was wondering does the ultrasonic sensor have to be exactly in line with an object for it to detect the correct distance? i would think the sound would bounce at the wrong angle and miss the reciever if it were approaching a wall at a slant.
Yes you are correct. However all you need is a bit of flat object in the distance to receive a signal back. Experiment, maybe you can find out the maximum angle at which the sensors recieve signals
Technic-R-C
Try this Tutorial:
An Introduction to Robot Sonar
My ultrasonic sensor detects most slants… I think the ultrasonic sensor is pretty good at detecting objects. It’s WAY better than the lego ultrasonic sensor! That thing was horrible. It read “???” most of the time…
Phew! i thought mine was broken…
thanx for the link Marko
i guess now i have to back up my ultrasonic sensors with bumper switches to avoid crashing into walls, but that kinda defeats the purpose of the ultrasonic sensor…
at least the robot looks smarter when it turns without hitting the wall.
I assume that you tested it with a Surface with good sound reflectance, at a Right Angle to determine the effectiveness of the Ultrasonic Sensor??
I just got me a pair of Parallax PINGS from Radio Shack. I am hooking them up right now.
How did you make out with these? How do they compare to the stock Vex sensor?
What you are asking for is something like a 180Degree Ultrasonic sensor that only existed in Robocop (it is an old show, older than many people in this forum) I feel old now :((.
Robots follow your orders and they can’t deal with what they’re not taught to deal with. So, if you want a sensor that can feel the world around it, then you would need to make the Ultrasonic sensor rotate 180Degree to cover the front side of the Robot. Basically, hook the sensor to a motor that moves to the right 90Degree starting from the center, and then it goes back to the center and moves 90Degree to the left.
Now a lot of questions will be raised in your mind regarding my solution. For example, what if the sensor is pointing in the wrong direction when the robot is heading to the wall? To solve such problem you would need to have another Ultrasonic sensor. We use it in the industry to know the RPM (round per minute) of rotating equipments. I posted some pictures for you to see how to hook it up. Positive with the red wire, Negative with the black, and the white wire with the third wire. This new Ultrasonic sensor can be used to tell the robot if the wheel is moving or not.
At normal conditions the robot is moving forward and the first Ultrasonic sensor is pointing forward, but once the Robot stops moving the second sensor detects the problem. Then the First sensor starts moving 180Degree to know where the blocking object is. From there the robot can navigate to a unblock itself.
I hope my explanation was not confusing. It also requires some coding skills.
What you are asking for is something like a 180Degree Ultrasonic sensor that only existed in Robocop (it is an old show, older than many people in this forum) I feel old now :((.
Robots follow your orders and they can’t deal with what they’re not taught to deal with. So, if you want a sensor that can feel the world around it, then you would need to make the Ultrasonic sensor rotate 180Degree to cover the front side of the Robot. Basically, hook the sensor to a motor that moves to the right 90Degree starting from the center, and then it goes back to the center and moves 90Degree to the left.
Now a lot of questions will be raised in your mind regarding my solution. For example, what if the sensor is pointing in the wrong direction when the robot is heading to the wall? To solve such problem you would need to have another Ultrasonic sensor. We use it in the industry to know the RPM (round per minute) of rotating equipments. I posted some pictures for you to see how to hook it up. Positive with the red wire, Negative with the black, and the white wire with the third wire.
This new Ultrasonic sensor can be used to tell the robot if the wheel is moving or not. At normal conditions the robot is moving forward and the first Ultrasonic sensor is pointing forward, but once the Robot stops moving the second sensor detects the problem. Then the First sensor starts moving 180Degree to know where the blocking object is. From there the robot can navigate to a unblock itself.
I hope my explanation was not confusing. It also requires some coding skills.
Sorry for the delay in responding…
I don’t have a Vex Ultrasonic Sensor (yet) and no one has any Data Sheets or Part Numbers for me to look at.
Look at thread, Ping)) Ultrasonic sensor. I have some fairly good data.
I am currently studying the PIC18F6520/8520/6620/8620/6720/8720 Data Sheet, for information on how the PIC handles all the I/O. It seems that PORTB (which is used for Vex Controller Interrupts #3-#6) detailed on page 106, is actually Bi-Directional, which means that it might be possible to use the PING))) with a single Ground/Power/Signal cable, unlike my current PING))) Setup or the Vex Ultrasonic Sensor. It might be possible to use the Vex Ultrasonic Sensor with a single Ground/Power/Signal cable as well.