Load Simulator for
Power Steering System
>>Background<<
In recent years, research on active safety
systems for cars has increased. One
example of such a system is “Lane
Keeping Aid”. In order to be able to test
and evaluate an actuator system for active
safety systems, this test rig has been
developed. The rig has the possibility to
reproduce and repeat real test case
scenarios in a safe way.
The test rig is built with a so-called
“hardware in the Loop” technique, where
the hardware and software cooperate.
Since the driver, a human, is involved in
the simulation; the rig can also be
regarded as a “Human in the Loop”
simulation.
>> Load Simulator <<
When a power steering unit is mounted in a car,
it is exposed to dynamic forces generated by the
connection between the tire and the road. In the
test rig these dynamic forces are simulated with
the help of a vehicle simulation model. The
forces are calculated within the vehicle model
from actual driving conditions, (slip angel,
vehicle speed etc.), and applied with the
hydraulic load cylinder. The configuration of the
power steering unit is nearly identical to the one
mounted in a car with the exception of the power
applied to the hydraulic pump, which is applied
by a frequency modulated electric motor.
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Power Steering Rack
Load Cylinder (Hydraulic)
Hydraulic Pump (PS)
Electronic Box
Frequency Mod. Electric Motor.
Force sensor
Load System Supply
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Marcus Rösth
[email protected]
Mekaniksystem
Copyright M Sethson 2001