I am using AL5 robotic arm. with the standard gripper. If i want to pickup the object (checkers piece) at certain distance how can i do it. I just know length of my arms components and distance of checkers piece from my arm.
in other words how can i set values for motion of servo’s based on distance to reach by the gripper.
If you are asking, how do I calculate the positioning of the arm. It’s done with Inverse Kinematics. This is a mathematical formula for defining the servo positions that will result in the gripper being positioned to the desired coordinates. Here are some examples.
I am using roborealm for vision processing, i am writing other programming in JAVA… i will be connecting my java code to roborealm with inbuilt “socket server” form roborealm…
also when you said it can be done with RIOS how exactly you would do it…
I’m saying RIOS utilizes IK for ease of positioning the arm. RIOS has a socket server as well. I don’t know what you want to do, so it’s difficult to provide advice.
I am creating checkers playing robot for my Masters project.
i use roborealm for image processing part. the information is sent to my java code. which is based on Obj Or designing concepts. I chose java because i am comfortable with java as compared to VB script.
Now i want to calculate the angles between arm’s component based on the distance of checkers piece from robots center.
i figured out that will be more appropriate for masters level instead of hard-coding all the possibilities and the choosing the move from the pool.
Did you look at the links I provided illustrating the IK math? I think that is what you are needing. I know enough about IK to be dangerous. lol I believe you need to determine the angle of the gripper as it relates to the ground plane. This is Forward Kinematics, then use Inverse Kinematics to determine the angles for the elbow and shoulder.
Anyone with more experience with IK can chime in here.
i am setting the angle of gripper to the ground to either -90 or -45 depending the quadrant in which my checker piece relies. i have kinda written the code based on the links you have provided but now i need to more precisely calibrate its working. will let you know if i have any doubts…
just one more question i coded all the equations as in xl file but my results are varying… do you know why ?
i am able to find the angles with the equations given in the links provided by you. but now how can i convert them to appropriate values for servos. in case of roborealm ranging from 500 to 2500 ? i ofund one equation on forums of lynxmotion. but when i apply those values robot doesn’t do positioning as expected.
To find the relationship between the pulses sent to a servo and the angle it moves to you must get a protractor and do some testing. Send it 1500, make that centered, then find the value needed to move it 90°. Each servo is different, analog, digital, etc. There is no magic formula, so you must find the values. After you have established a pulse to angle formula you can try the math again.
With RIOS we establish a separate calibration for each of the axis. Center, CW and CCW limits.
your suggestions worked pretty well, you can see the working on the following link. thanks alot for the help. if i have any doubts i will follow the same topic… thanks again.
I think you need to loosen the passive hinge there it’s not supposed to squeak like that. I think you missed the part in the base assembly where you sand off the imperfections of the plastic balls. This will make the base rotate work smoothly as well.
Can i have any reference to Inverse Kinematics formula… ? as i said before i have implemented one of the examples mentioned by you. but i still wanted to give it another try…
I have already given you 3 solutions to the IK math. If you have a specific question pertaining to the IK math please post them. I’m no math wiz, but there are many here who are.