How to use initkinematics in the robot joint control?

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Youichi I asked Dec 16, '19 Youichi I commented Dec 17, '19

How to use initkinematics in the robot joint control?

I wrote the following code, but it is not reflected in Current position. How should I program it?

treenode trb;

Object orb = model().find("Robot8");

initkinematics(trb, orb, KINEMATIC_MANAGE_ROTATIONS);

initkinematics(trb, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, KINEMATIC_MANAGE_ROTATIONS);

addkinematic(trb, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, 1,1,time(),KINEMATIC_TRAVEL);

updatekinematics(trb, orb); deactivatekinematics(trb);

Software Version:

FlexSim 18.1.2

robot arm

Answer 1 · 2019-12-16T14:05:58Z

Joerg Vogel answered Dec 16, '19 Youichi I commented Dec 17, '19

The node reference trb must be a real node in the tree. Typically you use a label at the robot for this task.

treenode robot = Model.find(“your own robot”);
robot.labels.assert(“yourKinematicNode”);
treenode trb = robot.labels[“yourKinematicNode”];

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Mischa Spelt commented · Dec 16, 2019 at 02:41 PM

Jörg, it may be worth adding that the last line is only used later in the code, when you need to access the label and already know it exists.

When creating it, I would grab the result from the assert:

treenode trb = robot.labels.assert(“yourKinematicNode”);

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Youichi I commented · Dec 17, 2019 at 09:14 AM

Jörg and Mischa,

Thank you for reply.

I modifed my script. But, I didn't set 10.0 to joint1.

Could you help me.

treenode robot = model().find("Robot8");

treenode trb = robot.labels.assert("variables/robotkinematics");

Object orb = model().find("Robot8");

initkinematics(trb, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0, KINEMATIC_MANAGE_ROTATIONS);
updatekinematics(trb, orb);
deactivatekinematics(trb);

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Brandon Peterson ♦ Youichi I commented · Dec 17, 2019 at 03:22 PM

The kinematic functions define the movement for a single object. Your code is defining the movement of the robot (the base) and not for the robot's joints. The reason that joint1 was not set to 10 is because the definition of the initkinematics() function says that you set the Robot's x location to 10 (y=20,z=30,xr=40,etc.). If you want to create kinematics for different parts of the robot then you will need to create a separate kinematic label for each part of the robot that you want to move.

I have included some highlights from the code on the robot that moves the arm that should help you out (I made some modifications to make it work in Flexscript):

Object robot = Model.find("Robot1");
treenode base = first(robot.find(">visual/drawsurrogate"));
treenode joint1 = first(base);
treenode joint2 = first(joint1);
treenode joint3 = first(joint2);
treenode joint4 = first(joint3);
treenode joint5 = first(joint4);
treenode joint6 = first(joint5);
treenode kinvariable = getvarnode(robot, "robotkinematics");
treenode joint1kin = rank(kinvariable, 1);
treenode joint2kin = rank(kinvariable, 2);
treenode joint3kin = rank(kinvariable, 3);
treenode joint4kin = rank(kinvariable, 4);
treenode joint5kin = rank(kinvariable, 5);
treenode joint6kin = rank(kinvariable, 6);
initkinematics(joint1kin, joint1, 0,0);
initkinematics(joint2kin, joint2, 0,0);
initkinematics(joint3kin, joint3, 0,0);
initkinematics(joint4kin, joint4, 0,0);
initkinematics(joint5kin, joint5, 0,0);
initkinematics(joint6kin, joint6, 0,0);

After the above code that initializes the kinematics for each joint the code goes on to add kinematics for the movement of each joint.

I hope this helps get you on track, Brandon

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Youichi I Brandon Peterson ♦ commented · Dec 17, 2019 at 06:04 PM

Brandon-san,

Thank you so much !

I can now control the flexsim robot in FlexScript.

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