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Specify the angle between two body axis vectors as a function of time
Library
Description
The Angle Driver block drives axis vectors defined on two Bodies. You specify fixed base and follower body axis vectors aB, aF in the Body CS on either side of the Driver on each body, then drive the angle between the body axis vectors as a function of time.
The Angle Driver block specifies the angle defined by
as a function of time: = f(t). You connect the Angle Driver to a Driver Actuator block.
The Simulink input signal into the Driver Actuator specifies the time-dependent driving function f(t) and its first two derivatives, as well as their units. If you do not actuate Angle Driver, this block acts as a time-independent constraint that freezes the angle between the two body axes at its initial value during the simulation.
Drivers restrict relative degrees of freedom (DoFs) between a pair of bodies as specified functions of time. Locally in a machine, they replace a Joint as the expression of the DoFs. Globally, Driver blocks must occur topologically in closed loops. Like Bodies connected to a Joint, the two Bodies connected to a Drivers are ordered as base and follower, fixing the direction of relative motion.
You can also connect a Driver block to a Constraint & Driver Sensor, which measures the reaction forces/torques between the driven bodies.
Dialog Box and Parameters
The dialog box has two active areas, Connection parameters and Parameters.
Connection Parameters
0
.The base (B)-follower (F) Body sequence determines the sense of positive motion. Positive rotation is the follower rotating in the right-handed sense about the rotation axis.
Angle Driver base and follower Body Connector Ports
Parameters
[1 0 0]
.WORLD
.See Also
Constraint & Driver Sensor, Driver Actuator, Parallel Constraint, Velocity Driver
See Modeling Constraints and Drivers for more on restricting DoFs with Drivers.
See Checking Schematic Topology and How SimMechanics Works for more on using drivers in closed loops.
See Creating Constraints and Drivers.
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