Documentation Center

  • Trial Software
  • Product Updates

Static and Kinetic Friction Library

This example shows a library containing blocks that allow you to actuate a single joint primitive at a time with these types of friction:

  • A mix of static and kinetic contact friction, proportional to static and kinetic friction coefficients and the force normal to the contact surface

  • Kinetic damping friction proportional to joint primitive velocity, either translational or rotational, but with opposite sign

These example library blocks are masked subsystems containing SimMechanics™ and Simulink® blocks.

The mixed static-kinetic friction block makes use of the Joint Stiction Actuator block from the SimMechanics™ Sensors & Actuators Library. If the connected joint primitive locks, that degree of freedom (DoF) is removed from the system. SimMechanics tests for locking and unlocking conditions with algebraic loops (non-time-based simulation steps) that can decrease the accuracy of your simulation, particularly if you use a fixed-step solver. Use such Joint Stiction Actuator blocks only if you need to lock and unlock jonits.

The kinetic damping friction block is a force element that applies a continuous friction force or torque via joint actuation using joint motion measured by a joint sensor.

Copyright 2008 MathWorks, Inc.

Was this topic helpful?