Multitasking Extension of Processor in the Loop PIL Simulation

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Multitasking Extension of Processor in the Loop
(PIL) Simulation

• Presented by
• Santiago Lentijo

2
Outline

• PIL Definition
• PIL Features
• New Feature Multitasking Capability
• Application Example
• Conclusion

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PIL Definition

• The PIL is a testing procedure for
  micro-controller based control where the real
  final target is adopted for software testing.
• The control software interacts with a simulated
  model of the plant (no real-time constraint)

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System Structure of PIL Simulation
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PIL Simulation
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PIL Features

• Independency between the blocks used in VTB and
  the processor used for the control.
• The communication software is modular, easy to
  customize to any number of inputs and outputs.
• Time length of the control algorithm. (Digital
  Output, VTB Viewable).
• Delay equal to the time length of the control
  algorithm.
• Problems related to the resolution of your
  processor (16 bits, 32 bits, fixed point).

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New Features

• Multitasking capability multiple tasks may be
  executed, apparently simultaneously, on a single
  processor.
• Time step independency and event scheduling the
  master simulator has to be able to do an
  intelligent step management, including time
  increment steps, state roll-back and adjustment
  of the time step.

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PIL Testing Procedure
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Application Example DC Motor Speed Current
Control
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Controller Design

• The DC motor can be represented as

PI Controllers
PI Parameters
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VTB PIL Results Step change of the reference
speed
Motor Speed VTB Result ?15.2µs
Motor Speed PIL Result ?15.5µs
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PIL Experimental Results Step change of the
reference speed
Motor Speed PIL Result ?15.5µs
Motor Speed Experimental Result ?16.15µs
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PIL Results ISampling Instants

• Task 1 is the Speed PI called every 3 ms
• Task 2 is the Current PI called every 0.3 ms

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PIL Results II Time length of the control
algorithm

• Task 1 is the Speed PI Maximum Time 189 µs
• Task 2 is the Current PI Maximum Time 155 µs

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PIL Results IIIMicrocontroller Memory Usage (In
percentage )
Max 69
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Conclusions

• PIL is a new procedure for virtual prototyping at
  signal coupling level.
• PIL allows the user to check the control software
  running together with a simulated model of the
  plant.
• PIL is not performed in real-time, but allows the
  measurement of important quantities such as
  execution time and memory usage that can increase
  confidence in the control software before the
  final testing.

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• Questions ?