DAGU robot arm with object Tracking
@ January 12, 2011
Tracks moving objects
Cost to build:
$300
Time to build:
100 hours
Weight:
3000 grams
- CPU: atmega168
- Power source: 12V 3A
- Sensors / input devices: IR compound eyes
Robot Arm with Object tracking Sensor. The IR eye is used as an Object detection and tracking sensor. For more details about the eye see: http://letsmakerobots.com/node/11293. The robot arm will try to keep the distance between the sensor and the object fixed. Based on the data received from the four IR sensors the controller will decide the suitable position of the servo motors to keep the distance between the sensor and the object fixed. The controller used for this project is the Wild thumper controller board. for more details about the controller see: http://letsmakerobots.com/node/24368.
@ Tue, 2011-04-05 11:55
Well Done!
About a year ago I had my assistant try the same thing. It seems to me that anyone wanting to build a robot arm needs to give it sensors of some sort so that it can align itself with an object.
Most robot arms assume that an object will be in a given location and fumble the object if it is slightly out of position. You should be able to use the compound eye to help the arm accurately align the gripper with an object.
@ Tue, 2011-04-05 14:43
pick up an object
Thanks OddBot....
I will try to program the arm to pick up an object when it is in the sensor range then put it in a basket. Whoever, I don't expect much from the compound eye since the measured signals depends greatly on the object color and size which makes the measurements not accurate. I think i must plot some curves for the response of this eye.
if using the Sharp IR sensors the results expectd to be more accurate.
@ Wed, 2011-04-06 02:22
The sensors on Mr. Tidy are
@ Tue, 2011-04-05 11:19
lol
seems like a scared little animal lol
@ Mon, 2011-04-04 18:49
The Robot is now finished
The Robot is now finished and tested. Any comments and/ or suggessions are welcomed.
@ Sun, 2011-01-30 18:16
The 6 servos and the angles
The Dagu robot arm has 6 DOF ( 6 servos). they are:
Range of Motion
Servo motors are controlled by pulse-width modulated signals that control the position of the servo actuator. Servo pulse widths vary from 500 to 2500 microseconds, which corresponds to a servo rotation angle of approximately 0° to 180°. A pulse width of 1500 microseconds will set the servo at the neutral position, or 90°. The range of motion and direction of travel for the servos used in the DAGU arm are summarized below:
Grip Servo
@ Sun, 2011-01-30 17:59
the Grip
if it is required to set accurate position of the robot arm then the Grip length must be calculated in term of grip width. The Grip used in this arm is from DAGU.The grip mechanism uses a scissor action to open and close the gripper, so the grip length changes depending on the grip width. The relationship of length to width was determined to be a third order polynomial( see http://letsmakerobots.com/node/24441):
y = -0.0181x3 + 0.0557x2 - 0.2001x + 10.64
where, y; is the Grip length and x is the grip width
@ Tue, 2011-01-25 17:30
phase #1
Phase #1 of this project is to build the required software that guide the robot arm to specified position in 3-D space. this software will depend on inverse kinematic equations to estimate the joints angles. then, a lookup table will be used to find the required servos pulse widths.
@ Sat, 2011-01-22 18:08
the new controller
I got the new controller last week. however i could not install the software in the CD. it is not working neither in my laptop with windows vista) nor in my desktop( with windows XP sp2). when i tried direct commands it works fine, so i wrote my own software in VB script running on excel sheet.
the overall current drawn is higher than before and the servo speed is very high.
@ Fri, 2011-01-14 16:01
cost
@oddbot:How much does this arm costs ?