Control of Machines with Friction

1. Introduction.- 2. Friction in Machines.- 2.1. The Contemporary Model of Machine Friction.- 2.2. Boundary Lubricants: a Domain of Many Choices.- 2.3. Relaxation Oscillations.- 2.4. Friction Modeling in the Controls Literature.- 2.5. An Integrated Friction Model.- 3. Experiment Design.- 4. Repeatability.- 5. Break-Away Experiments.- 5.1. Experimental Issues in Measuring Break-Away Torque.- 5.2. Building the Compensation Table.- 6. Friction as a Function of Velocity.- 6.1. Analysis of Variance in the Motion Friction Data.- 6.2. Friction at Low Velocities.- 6.3. Friction During Compliant Motion.- 6.4. The Dahl Effect.- 6.5. The Stribeck Effect.- 6.6. Temporal Effects in the Rise and Decay of Friction.- 6.7. Variance in Friction as Process Noise.- 7. Analysis of Stick-Slip.- 7.1. Dimensional Analysis.- 7.2. Perturbation Analysis.- 7.3. The Impact of Static Friction Rising as a Function of Dwell Time.- 7.4. Integral Control.- 8. Demonstrations of Friction Compensation.- 8.1. Open-Loop Motion of One Joint.- 8.2. Open-Loop Motion of Three Joints.- 8.3. Friction Compensated Force Control.- 9. Suggestions Toward Friction Modeling and Compensation.- 9.1. Suggestions on Experimental Technique.- 9.2. Suggestions on Control.- 9.3. Conclusion.- Appendix A: Small Studies.- A.1 Friction as a Function of Motor Angle.- A.2 Joint 2 Motor Alone and Joint 2 Link Alone.- A.3 Trials with Dither.- A.4 Friction as a Function of Load.- A.5 Creep.- A.6 Effects that were not Observed.