Greetings all I was hoping to get some robot physics simulation people's ideas here.
Looking at the LSL Vehicle API, it seems clear that there is at least an angular motor and a linear motor involved. There may be two angular motors, one for the angular movement and one for the vertical attractor(which may just be a jacobian constraint). In ODE, angular motors are implemented as springs. Sometimes this can cause instability and vibration. The truth is, using ODE's angular motor may or may not be the best solution. There are others. For example, on the ODE-users list currently they're talking about applying torques directly using the Recursive Newton-Euler formulation. " desired joint velocities and accelerations (qp and qpp respectively), then the joint torques can be calculated with: tau = M(q) * qpp + V(q,qp) + G(q) + F(qp) where M(q) is your inertia matrix and V(q,qp) is a vector of the coriolis forces, G(q) is a vector of the gravity forces and F(qp) is a vector of fiction forces. " Recursive Newton-Euler formulation http://www.cours.polymtl.ca/roboop/docs/node146.html A list of some constants in the LSL Vehicle API: ANGULAR_DEFLECTION_EFFICIENCY ANGULAR_DEFLECTION_TIMESCALE ANGULAR_FRICTION_TIMESCALE ANGULAR_MOTOR_DECAY_TIMESCALE ANGULAR_MOTOR_DIRECTION ANGULAR_MOTOR_TIMESCALE BANKING_EFFICIENCY BANKING_MIX BANKING_TIMESCALE BUOYANCY HOVER_EFFICIENCY HOVER_HEIGHT HOVER_TIMESCALE LINEAR_DEFLECTION_EFFICIENCY LINEAR_DEFLECTION_TIMESCALE LINEAR_FRICTION_TIMESCALE LINEAR_MOTOR_DECAY_TIMESCALE LINEAR_MOTOR_DIRECTION LINEAR_MOTOR_OFFSET LINEAR_MOTOR_TIMESCALE VERTICAL_ATTRACTION_EFFICIENCY VERTICAL_ATTRACTION_TIMESCALE Thoughts and patches appreciated. You'll find a mostly logically complete ODEVehicleSettings.cs in OpenSim.Region.Physics.OdePlugin.ODEVehicleSettings.cs that contains all of the constants as well as methods that are plugged in to the physics plugin, but don't take any action in the physics engine yet. This was created to organize vehicle API development. Best Regards Teravus _______________________________________________ Opensim-dev mailing list [email protected] https://lists.berlios.de/mailman/listinfo/opensim-dev
