FunctionBay Technical Support Site | TSG (Time Signal Generator)

The TSG (Time Signal Generator) toolkit has been added to RecurDyn. The TSG finds a Drive Signal that causes the MBD system in RecurDyn to produce a measurable system response that is similar to a user-defined Target Signal. The MBD system response can be any value, such as a displacement, a velocity, an acceleration, a force, or a sensor output.

The TSG is designed for virtual testing of mechanical systems. It is often desired to reproduce a known response in a mechanical system in a controlled environment. The known response might have been experimentally measured. It might be a position of a part or the acceleration of it, for example. This known response is referred to as the Target Signal.

In the controlled testing environment, the mechanical system might be driven by inputs to the mechanical system or actuators of a test rig. These inputs are referred to as Drive Signals. In order to reproduce the desired response in the testing environment, appropriate Drive Signals are needed.

For most mechanical systems, manually deriving or calculating the Drive Signals required to produce the Target Signal is very difficult or impossible. Most mechanical systems are highly nonlinear with many complex components that are difficult to predict by hand. A tool that can find the proper Drive Signals is required.

In RecurDyn, the TSG is the tool that finds the drive signal.

Background

In general, the responses of a mechanical system is measured at several places of it. (Acceleration, Velocity, Position, Force and others)
This known response is referred to as the Target Signal.
The measured data from the experiment usually cannot be used for MBD/MFBD model.
- They are the output signal of the specific location, it is difficult to apply it to RecurDyn model directly.
- Most mechanical systems are highly nonlinear with many complex components so that those output signals are difficult to be used in a MBD/MFBD model.
- In order to reproduce the desired response in the testing environment, appropriate Drive Signals are needed.

Procedure of TSG

Create sensors where the response of a real system is measured in a RecurDyn model.
Create actuators to produce the response in a RecurDyn model.
With the iterative simulation, RecurDyn/TSG finds the proper Drive Signal to reproduce the Target Signal.
If the responses of the sensors are similar to the measured Target Signals, then RecurDyn model can be regarded that it is actuated similarly to the real system.

Features

Create virtual sensors in the RecurDyn model in the same location as the sensors used to measure the target signal in the real mechanical system.
Actuator : Drives the system at a various location of the system. It is defined using a Joint Motion or a Force in a MBD model. (using a function, ‘TACT(…)’ in an expression)
Sensor : The response of a system is calculated using sensors. Eventually, the responses of the sensors should match the user-defined Target Signals closely.
Target Signals: User-Defined Signals that was measured from experiment which should be reproduced using the appropriate Drive Signals.
Response Signals: Outputs of RecurDyn at the location of the virtual Sensors. Using iterative simulation, the response signal at the end of the process should match the Target Signals.
Drive Signals: Inputs of MBD model at the location of the virtual actuators.
FRF (Frequency Response Function)

Benefits

The TSG enables RecurDyn to be used as a virtual test rig. It enables RecurDyn to rapidly find the Drive Signal that reproduces the Target Signal in computationally efficient, reduced complexity models.
The simplified virtual test-rig model eliminates various nonlinearities of the actual test environment, and enables faster and simpler dynamic analysis. In addition, the TSG can be combined with RecurDyn's MFBD (Multi Flexible Body Dynamics), allowing the user to perform both stiffness and durability analysis in a single environment of RecurDyn.

TSG Tutorial

TSG Toolkit Tutorial & Example files