|
Kinematic & Compliance Test Rig
The Kinematic & Compliance Test Rig is designed to determine the behaviour of the car’s suspension when subjected to multiple D.O.F. loads while forced to move in different directions.
The excitation can be single or double car’s axle.
The quality of the test system is defined by the rigidity of the reaction frame, the 6 D.O.F. wheel’s movements measurement accuracy and the tire patch point loads measurement accuracy.
Servo2000 has designed and manufactured the single axle , 5 D.O.F. per wheel Titan system.
The D.O.F. for each wheel are : vertical, x movement, y movement, wheel pan rotation and rolling.
Besides those movements the system can apply a rotation of the steering wheel acting directly on it or on the steering column in case the car is not available yet.
To drop down set-up time, the steering movement is performed by means of a retractable arm with at his end a small electrical motor and adapter to steering wheel . The retractable arm is inserted through the driver door’s window glass or passenger for left end drive cars.
For double axis test the car set up is made only once. The car in fact is moved on a rail by means of an 8 meter stroke electromechanical actuator and an hydraulic supported and locked sled.
After the test of the front axle a PLC controlled system moves the car with the rear axle on the test actuator and allow the start of the test.
At completion the sled is unlocked form the frame and moved back in the pick-up area where a car lifter frees the car from the sled and lower at floor level again.
To guarantee the maximum loads / displacements stability the TITAN system is fully electromechanical. | Type Contact Patch Motion | Range | | Vertical (Dz) | +/- 260 mm | | Lateral (Dy) | +/- 75 mm | | Longitudinal (Dx) | +/- 75 mm | | Rotation around Z (Rz) | +/- 45 deg | | Rotation around X (Rx) | +/- 45 deg |
| | | Applied Loads | Range | | Vertical (Fz) | +/- 30000 N | | Lateral (Fy) | +/- 14000 N | | Longitudinal (Fx) | +/- 14000 N | | Aligning torque (Mz) | +/- 2250 Nm | | Torque around X (Mx) | +/- 4000 Nm | | Steering torque) | +/- 100 Nm |
|
Besides the extraordinary rigidity ( the sled moves about 10 micron with 30,000 N applied on both sides) the main peculiarities of the Titan system is the type of measurement for the 6 D.O.F. of the wheel movements and loads.In fact the movements measurement is carried out by an infrared non-touch system manufactured by the company Krypton while the 6 D.O.F. loads are measured by a load platform manufactured by the company IGEL. The load platform has in the middle a conditioning and digital converting unit HUB. The data are transmitted in serial form on a single cable. The receiver reconverts the serial data into a set of data to be used by a DSP to calculate with high accuracy each of the six loads. The use of infrared transmitters that can be daisy chained (each of the dimensions and weight of a button of jacket) allows to measure the 6 D.O.F. movement of the wheel pan , of the wheel centre and the deformation of the car frame above the wheel in order to consider it for mathematical model validation.
As the sled if formed by two parts it can be joined together and test a small axle distance car like the Smart or open and test long axle distance vehicle as the IVECO Ducato. When the sled is open in two parts it allows the use of an adapter frame to mount R&D suspensions which have to be tested before the car is available.
The Titan system allows to program the following INPUT
- Vertical Load/displacement
- Lateral Load/displacement
- Longitudinal Load/displacement
- Aligning Torque / rotation
- Torque around X/rotation
- Steering Torque / rotation
- Combined Load
and to measure all the needed parameters to calculate the following Outputs
- Toe change
- Camber change
- Wheelbase change
- Track change
- Wheel vertical rate
- Steering axis properties
|
