4 DOF Scara robot parametric calibration

Paper details: have already done literature review part, calculated forward kinematics using D-H parameters. I created dataset using points in workspace of Scara robot. Kinematics error model is established and error of end-efffectors X, Y Z positions are calculated according to the given joint angles errors for each point. The error model should be checked. An optimisation code should be written to identify geometric parameters in order reduce these errors. Now, I need: 1. find singularity, using or not using these points depend on you, but you should explain why ) 2. Determine an optimisation algorithm which has to optimise parameters (e.g. links parameters, of 4 DOF Scara robot in order to reduce errors. Identify the kinematic parameters 3. Discard most sensitive areas and apply this algorithm. 4. All codes of algorithm, graphs, calculations are required as additional material