Open-loop controllers define vehicle inputs directly without feedback (for example, steering wheel angle vs. time). Open-loop controllers can be used for all vehicle inputs. However, without feedback signals, no mechanism exists for the driver to achieve a desired vehicle response (for example, speed or path following). The vehicle’s properties alone determine its response to the open-loop inputs.
Use Cases:
| • | Using experimental data \ data collected from real life testing such as steering wheel angle or throttle as vehicle inputs. |
| • | Expression driven outputs - ‘SIN(TIME)’ , ’10.85’. |
| • | Identifying vehicle properties like yaw-rate gain. |
| • | Passing the signals computed from user defined controllers thru Altair Driver to the vehicle inputs. |
Supported Driver Output Signal(s) - All
Altair Driver File Keyword Types:
| - | Link MotionView solver-variable |
| - | Link driver signal to user written logic |
| - | Populate driver signals from curve data |
| - | Expression driven driver signal |
| - | Expressions syntax must be consistent with MotionSolve |
| - | Example – ‘SIN(TIME)’ or ‘STEP(TIME, 1,0,1,2)’ |
Example open loop controller block in the Altair Driver File:
[OPEN_LOOP_CONSTANT]
TAG = 'OPENLOOP'
TYPE = 'CONSTANT'
VALUE = 0.5
This creates a constant signal of value, 0.5.
