General
descriptionGeneral
description
SYM is a program package for customized robot modeling. It generates C programs for the computation of robot kinematic and dynamic models in symbolic form with the near minimum number of numerical operations, for the given kinematic and dynamic parameters. It can also generate closed-form analytical expressions of dynamic equations. Besides, SYM provides a possibility to simulate the system behaviour for various control laws. SYM runs on PC computer under MS-DOS operating system.
Kinematic models
Sym can generate C language programs for the computation of the homogeneous transformation matrix between the end effector coordinate frame and the base reference frame. It also generates customized programs for the computation of the Jacobian matrix that corresponds to the manipulator tip position and angular velocities of the end-effector. Two types of Jacobian matrices are available: The Jacobian matrix with respect to the base frame, and the Jacobian matrix expressed with respect to the end-effector coordinate frame. SYM takes into account the special structure of each robot mechanism, and minimizes the number of floating point operations required for the model computation. For example, for the computation of the Jacobian matrix with respect to the base frame for 6 degree-of-freedom PUMA robot, the C-code program requires 71 floating point operations, while the computation of the homogeneous transformation matrix requires 69 floating point operations.
Dinamic models
There are five types of robot dynamic models that SYM can generate: complete driving torques in the manipulator joints, the inertial matrix, the vector of gravitational forces, the vector of Coriolis and centrifugal terms, the vector of gravitational, Coriolis and centrifugal terms. The number of floating point operations is minimized. For example, the computation of the complete driving torques for a 6 degree-of-freedom PUMA manipulator requires 340 floating point operations (when each manipulator link is a described by three main moments of inertia).
Control Laws Source Code Generation
There is a variety of available control law structure that SYM can generate starting from the simplest PID regulators to the most complex dynamic control laws, such as computed torque method. The user may define the algebraic expression of the desired control law, and a C program will be generated that perform the computation of the desired control law.
System Simulation
SYM generates the executable image for the system simulation. The simulation includes the dynamics of the mechanical part of the system and actuators (DC motors). The user should specify the parameters that are needed during the simulation: altered dynamic parameters of the system, white noise variance for the measured signals, different sampling periods, initial position, velocity and currents, acquisition data during the simulation. Graphical presentation of the simulation results is included.
Potential users