Introduction

Active safety systems become increasingly important in passenger cars. TNO builds a Pre-Crash Test System (PCTS) in its VeHIL (Vehicle Hardware In the Loop) laboratory in Helmond. The PCTS should be capable of testing active safety systems that are implemented in passenger cars for a wide variety of scenarios. Such safety systems generally make use of a combination of sensors (often radar), smart control algorithms and actuators, e.g. to autonomously brake to avoid or mitigate a collision.

In the VeHIL laboratory, the Vehicle Under Test (VUT) is put on a rollerbench, and real life scenarios are provided to the active safety system(s) by means of moving objects around the VUT. The VUT itself is not moving, although it drives on the rolls of the rollerbench. A control system ensures that the movement of the objects is coupled to the velocity of the VUT (in the loop). TNO has patented this approach of relative velocity.

Since Collision Mitigation by Braking (CMbB) systems should reduce the impact speed of a collision, actual crashes take place between the objects and the VUT. To avoid high costs and for safety reasons, these crashes are supposed to be ‘mild’, for instance by using balloontargers that are constructed in such a way that radar properties resemble a real car, but no damage results from a crash.  

A Proof-of-Concept system has been designed. A balloontarget is displaced over a length of 80 m by a cable with a maximum speed of 80 km/h. The mass of the balloontarget and the connection equipment to the cable is approximately 200 kg. Accelerations and decelerations of the target are expected up to 10 m/s2. Next step is to incorporate lateral movement (y direction +/- 4 m) and yaw rotation (+/- 135 deg) of the balloontarget. Next to that also the propulsion system (motor and cables) should not interfere with other moving objects in the facility, the so called moving bases.

Your assignment

The objective of this assignment is to determine a solution to the lateral movement, yaw rotation of the balloontarget and the placement of the propulsion system. The goal is to fully automate this movement to be able to control the postion realtime from the fixed world. Therefore the challenge is both the physical (lightweight) construction, but also the communication and power supply towards the moving balloontarget.

The assignment is expected to follow the next project steps (methodical design):

1)       Set up the requirements regarding the PCTS system; the lateral movement and yaw rotation in combination with the requirements of the longitudinal movement.

2)       Define different mechatronical concepts.

3)       Select the most promising concept, detail it and prove that it fulfills the requirements of step 1.

4)       Write a report, draw conclusions and make recommendations towards the final design of the PCTS system. 

The timeline for this assignment is about 6 months. We expect you to have a decent knowledge of mechatronic concepts (university level), a drive to solve challenging problems and good communication skills.

Contact

John Vissers

Phone:                    088 86 62214

Email:                     john.vissers@tno.nl

Hanno Schouten

Phone:                    088 86 65792

Email:                     hanno.schouten@tno.nl