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Narrow Track Vehicle

Abstract:
A reduced-scale three-wheeled tilting vehicle prototype has been developped. It allows to analyze the control of a narrow track vehicle. Several sensors equip the prototype. The multibody model is compared with experimental results.

Keywords: Narrow track vehicle ; Vehicle Dynamics ; Multibody Modeling ; Direct Tilting Control

The interest in Narrow Tilting Vehicle (NTV) has increased recently as it offers the possibility to tackle both traffic congestion and carbon emissions.

With a small footprint, low weigth and narrow track, these vehicles are likely to increase the utilization of existing freeways and parking facilities while being energy efficient. Their large height-to-track ratio leads to a reduced stability and requires tilting towards the inside of a turn while cornering.

For the purpose of research about control of these vehicles, a reduced-scale three-wheeled tilting vehicle prototype has been built.

With the help of multibody simulations, this demonstrator allows to analyze dynamic performances and validate the conception.

Narrow Track Vehicle : propulsion and suspension
Narrow Track Vehicle : propulsion and suspension

Tilting and steering

Mechanical limits of the vehicle steer and tilt at the front suspension are estimated thanks to the modelisation and compared with experiments.

Narrow Track Vehicle : tilt and steer angles
Narrow Track Vehicle : tilt and steer angles

Sensors

First, a strain gauge is put on the front binocular to provide a torque information associated with the actuated tilting degree of freedom of the vehicle.

This sensor was designed on the existing “T” shaped load struture of the vehicle.

Narrow Track Vehicle : torque sensor
Narrow Track Vehicle : torque sensor

Moreover, an other sensor has been built to measure the absolute value of the tilt angle of the frame of the demonstrator.

This position is thus measured directly on the tilting actuator, by means of a gear ratio, transmitting this motion to a potentiometer

Narrow Track Vehicle : tilt sensor
Narrow Track Vehicle : tilt sensor

Results

The behavior of the vehicle in a curve is assessed, using two control schemes: STC and DTC

The prototype moves forward at a constant speed of 1 m/s, while the curvature radius is set between 0m (straight line) and ± 2.5m. For the DTC control, is gives the figures below for an corner entry:

DTC cornering entry of the NTV
DTC cornering entry of the NTV

For varius curvature radii, the vehicle is able to follow the reference:

vehicle behavior with STC control
vehicle behavior with DTC control

Finally, the prototype does not currently allow to test the STC control scheme. Indeed, it would need to disconnect the tilting actuator from the rest of the vehicle.

Dynamic Lab

See also other experimental applications of Robotran : https://www.robotran.be/applications/labo-dyn/

References

Partner institutions

Model contributors

Quentin Docquier, Pierre Ghijselings, Sébastien de Longueville, Sébastien Timmermans, Paul Fisette.