Sensor to track moving beacon?
AnthonyRose
BannedPosts: 2
I'm brainstorming a project.
It's a cable cam to follow and film me as I cycle through the woods. The general concept has been implemented by others many times. A carriage with an attached camera rides on pulleys on a cable suspended between two trees. Ideally the camera keeps the subject centered in the video. Sometimes this is implemented with a motor and a remote control, to be controlled be a third party. Sometimes the cable is angled and the carriage moves by gravity.
I would like to implement an autonomous motorized version. This eliminates the need for a third party, and allows uphill movement.
A microcontroller will use some kind of sensors to determine if it needs to speed up or slow down a motor to keep me centered in view. I assume it won't be analyzing video because that would be too costly. Correct me if I'm wrong.
I will be using a GoPro HD camera, which has a very wide angle. It actually looks best only about 4' away. But I'd like the ability to get about 20' away and still track me. I will generally be doing more technical riding and hill climbing. So generally I'll be moving at about 5mph or less, but I may get up to 10mph occasionally.
At first I thought a wiimote IR camera and IR leds could be used. I would wear the IR leds, and the wii camera would track my IR blob. Unfortunately sunlight confuses the wiimote too much.
I then started looking at ultrasonic sensors. I could wear a transmitter that pulses an ultrasonic signal. The carriage could have two ultrasonic receivers mounted on opposite ends, like ears. Based on time of arrival, the microcontroller could determine which way it needs to move.
Any thoughts on this?
Will ultrasonic work?
What would be better?
Visible light would be seen in the video... so that's not preferred.
RF?
Something else?
Thanks for any suggestions.
Ion
It's a cable cam to follow and film me as I cycle through the woods. The general concept has been implemented by others many times. A carriage with an attached camera rides on pulleys on a cable suspended between two trees. Ideally the camera keeps the subject centered in the video. Sometimes this is implemented with a motor and a remote control, to be controlled be a third party. Sometimes the cable is angled and the carriage moves by gravity.
I would like to implement an autonomous motorized version. This eliminates the need for a third party, and allows uphill movement.
A microcontroller will use some kind of sensors to determine if it needs to speed up or slow down a motor to keep me centered in view. I assume it won't be analyzing video because that would be too costly. Correct me if I'm wrong.
I will be using a GoPro HD camera, which has a very wide angle. It actually looks best only about 4' away. But I'd like the ability to get about 20' away and still track me. I will generally be doing more technical riding and hill climbing. So generally I'll be moving at about 5mph or less, but I may get up to 10mph occasionally.
At first I thought a wiimote IR camera and IR leds could be used. I would wear the IR leds, and the wii camera would track my IR blob. Unfortunately sunlight confuses the wiimote too much.
I then started looking at ultrasonic sensors. I could wear a transmitter that pulses an ultrasonic signal. The carriage could have two ultrasonic receivers mounted on opposite ends, like ears. Based on time of arrival, the microcontroller could determine which way it needs to move.
Any thoughts on this?
Will ultrasonic work?
What would be better?
Visible light would be seen in the video... so that's not preferred.
RF?
Something else?
Thanks for any suggestions.
Ion
Comments
No tracking at all. Make several dry runs recording the desired movement and have it play back. It would need to be remote controlled, XBees and a small joystick would work well.
Use the wheel speed to control the cable cam's speed. Would work fine for level ground, might work for what you are doing.
Have a handlebar mounted control to adjust the speed. Three buttons, Start/Stop, Increase and Decrease. Each tap would ramp the speed up or down a certain amount. Start and Stop would also smoothly ramp.
Rich H
http://forums.parallax.com/showthread.php?125661-Sensor-to-track-moving-person
Deja vu!
Rich H
You will need transmit the camera image back to your multiplexer via receiver. You can get these multiplexers from security supply houses or on the internet.
I hope this gives an idea how can be done.