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Repeating Sequence

Generate arbitrarily shaped periodic signal

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  • Repeating Sequence block

Libraries:
Simulink / Sources

Description

The Repeating Sequence block outputs a periodic scalar signal having a waveform that you specify using the Time values and Output values parameters. The Time values parameter specifies a vector of output times. The Output values parameter specifies a vector of signal amplitudes at the corresponding output times. Together, the two parameters specify a sampling of the output waveform at points measured from the beginning of the interval over which the waveform repeats (the period of the signal).

By default, both parameters are [0 2]. These default settings specify a sawtooth waveform that repeats every 2 seconds from the start of the simulation and has a maximum amplitude of 2.

Examples

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Open Model

This example shows how you specify a waveform with the Repeating Sequence block. In this model, the block defines the Time values parameter as [0:0.1:0.5] and the Output values parameter as [0 15 25 09 13 17]. The stop time of the simulation is 0.7 second.

  • Input period is 0.5.

  • Output at any time t is the output at time t = t-0.5n, where n = 0,1,2, and so on.

  • Sequence repeats at t = 0.5n.

At t = 0.5, the expected output is equal to the output at t = 0, which is 0. Therefore, the last value in the Output values parameter vector [0 15 25 09 13 17] does not appear.

Extended Examples

Model Fault-Tolerant Fuel Control System

Model Fault-Tolerant Fuel Control System

Combine Stateflow® and Simulink® capabilities to model hybrid systems. This type of modeling is particularly useful for systems that have numerous possible operational modes based on discrete events. Traditional signal flow is handled in Simulink while changes in control configuration are implemented in Stateflow. The model described in this example represents a fuel control system for a gasoline engine. The system is robust in that it detects individual sensor failures, and the control system is dynamically reconfigured for uninterrupted operation.

Two Cylinder Model with Load Constraints

Two Cylinder Model with Load Constraints

Use Simulink® to model a rigid rod supporting a large mass interconnecting two hydraulic actuators. This model eliminates the springs as it applies the piston forces directly to the load.

Simulating Systems with Variable Transport Delay Phenomena

Simulating Systems with Variable Transport Delay Phenomena

Two cases where you can use Simulink® to model variable transport delay phenomena.

Ports

Output

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Output signal specified by the Time values and Output values parameters to create a periodic scalar signal.

Data Types: double

Parameters

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Vector of strictly monotonically increasing time values. The period of the generated waveform is the difference of the last and first values of this parameter.

Programmatic Use

Block Parameter: rep_seq_t
Type: character vector
Values: vector
Default: [0 2]

Vector of output values that specify the output waveform. Each element corresponds to the time value in the Time valuesparameter.

Programmatic Use

Block Parameter: rep_seq_y
Type: character vector
Values: vector
Default: [0 2]

Block Characteristics

Data Types

double

Direct Feedthrough

no

Multidimensional Signals

no

Variable-Size Signals

no

Zero-Crossing Detection

no

Algorithms

The block sets the input period as the difference between the first and last value of the Time values parameter. The output at any time t is the output at time t = t-n*period, where n is an integer. The sequence repeats at t = n*period. The block uses linear interpolation to compute the value of the waveform between the output times that you specify.

Extended Capabilities

Version History

Introduced before R2006a

See Also

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