Seeking Advice on a Generic Analytical Method for Inverse Kinematics of Various Robot Manipulators

Question

I’m working on developing a generic analytical method to solve the inverse kinematics (IK) for different types of robotic manipulators. My goal is to create a solution that can handle various robot configurations (6DOF without a spherical wrist, 4DOF SCARA, 7DOF, etc.) by simply changing the Denavit-Hartenberg (DH) parameters for each robot.

Here’s my current approach for 6DOF:

1. Define the DH parameters for the specific robot.
2. Get the overall transformation matrix from the base to the end effectorusing the homogeneous transformation matrices for each link + the DH parameters,
3. Set the overall transformation matrix equal to the desired end effector pose (4x4 matrix).
4. Manipulate(algebraically) the equations to isolate and solve for the unknown joint angles in some doable order. (This step varies depending on the robot's structure.)

However, I’m uncertain if a truly generic solution is feasible given the variety in robot structures and complexities of the equations. I’m looking for advice or confirmation on the following:

• Is it possible to create a single analytical method that works for different types of robots by just changing the DH parameters?
• Are there best practices or techniques to simplify this process for various robot configurations?
• How should I handle specific cases, such as SCARA robots or manipulators with more than six degrees of freedom?

Any insights or suggestions would be greatly appreciated!

Thank you in advance!

Answer 1

Typically, the generic way to solve IK is to use numeric, iterative solvers, rather than analytic. See this previous answer for references.

There is one general analytic solver that I know of: OpenRave, but I have no experience with it.