matlab debounce,Debounce Signals

Key Behaviors of Debouncer Chart

The key behaviors of the Debouncer chart are:

Intermediate Debounce State Isolates Transients

In addition to the states On and Off, the Debouncer chart contains

an intermediate state called Debounce. The Debounce state isolates

transient inputs by checking whether the signals retain their positive

or negative values, or fluctuate between zero crossings over a prescribed

period of time. The logic works as follows.

If the input signal…Then this state…Transitions

to…And the…Retains positive value for 0.1 secondDebounce.OnOnSwitch turns on

Retains negative value for 0.1 secondDebounce.OffOffSwitch turns off

Fluctuates between zero crossings for 0.3 secondDebounceOff.FaultNote:

The Debounce to Off.Fault transition comes from a higher level

in the chart hierarchy and overrides the transitions from the Debounce.Off

and Debounce.On substates.Chart isolates the input as a transient signal and gives

it time to recover

Temporal Logic Determines True State

The

debouncer design pattern uses temporal logic to:Determine whether the input signal is normal or transient

Give transient signals time to recover and return

to normal state

Use Absolute-Time Temporal Logic.The debouncer design uses the after(n,

sec) operator to implement absolute-time temporal logic

(see Operators for Absolute-Time Temporal Logic). The keyword sec defines

simulation time that has elapsed since activation of a state.

Use Event-Based Temporal Logic.As an alternative to absolute-time temporal logic, you can apply

event-based temporal logic to determine true state in the Debouncer

chart by using the after(n, tick) operator

(see Operators for Event-Based Temporal Logic). The keyword tick specifies

and implicitly generates a local event when the chart awakens (see Control Chart Execution Using Implicit Events).

The Error Generator block in the sf_debouncer model

generates a pulse signal every 0.001 second. Therefore, to convert

the absolute-time temporal logic specified in the Debouncer chart

to event-based logic, multiply the n argument

by 1000, as follows.

Absolute Time-Based LogicEvent-Based Logicafter ( 0.1, sec )after ( 100, tick )

after ( 0.3, sec )after ( 300, tick )

after ( 1, sec )after ( 1000, tick )