How does robot kinematics choose one set of solutions

When I use simulink to simulate, add the control block and the set trajectory before the inverse kinematics of the robot arm, and the result kinematics calculates two sets of solutions, so how do I choose one of the correct ones?

Answer 1

[Karan Singh]

When using Simulink to simulate a robot arm with inverse kinematics, it is common to encounter multiple solutions for the robot's joint angles.

To choose one of the correct solutions, you can consider the following approaches:

1. Joint limits: Check if any of the solutions violate the joint limits of the robot arm. If a solution exceeds the joint limits, it is not physically feasible, and you should discard it.
2. Joint velocity and acceleration: Evaluate the joint velocities and accelerations for each solution. Choose the solution that results in smooth and feasible joint motions. Avoid solutions that lead to abrupt or excessive joint movements.
3. Manipulability: Assess the manipulability of the robot arm for each solution. The manipulability measures the ability of the robot to move in different directions. Higher manipulability indicates better dexterity. You can use manipulability metrics, such as the Jacobian or condition number, to compare the solutions and select the one with better manipulability.
4. Task-specific criteria: Consider any task-specific requirements or constraints. For example, if you need the robot to avoid obstacles or follow a specific trajectory, you can evaluate how well each solution satisfies these criteria

Here are some threads to follow Inverse Kinematic Solver solutions - Help Center - MATLAB & Simulink (mathworks.com) and find more on Quora, and intechopen which gives optimization techniques which converses the best solution.