Reaction times in traffic: an innovative test method using HBM technology
In traffic, it often comes down to a matter of milliseconds. How do we react at the wheel in dangerous situations? How quick are we to hit the brakes? Situations that are very difficult to recreate in the laboratory. With the aid of HBM measurement technology, Swiss engineer Mauro Balestra has developed a way of recreating dangerous situations in a test vehicle, under real traffic conditions.
Automotive traffic is increasing all over the world, and with it the complexity of the situations that we, as motorists, have to deal with, day in day out. Automotive manufacturers throughout the world are working to further improve vehicle ergonomics and engineering, so that all of us on the road can enjoy the highest level of safety.
But data about drivers’ responses and reaction times obtained under laboratory conditions, in simulators, are not always meaningful, because too many factors are ignored and too little consideration is given to the “human factor”. This is also the conviction of engineer Mauro Balestra, who lives in Tessin, in Switzerland. The reaction of the vehicle driver that is artificially simulated and recorded in the research laboratory, is not the same as actual reactions in a real car and on a real road.
Innovative Test Method
So Mauro Balestra and his consulting engineers at “Balestra CSR-Centro Studi e Ricerca” developed an innovative method of accident diagnosis, in which a test vehicle is fitted with sensors, to analyze the driver’s reactions during a braking maneuver under real traffic conditions. A camera records the movements of the motorist’s face muscles. The pictures taken by the camera are then compared with a variety of measurement data (such as speed, steering wheel position, gas pedal position, pedal brake force, ABS sequence, distance traveled, delay, etc.).
With this test setup, it is possible to measure and analyze the “Perception-Reaction Time” (PRT) of the vehicle driver in different dangerous situations on the road. In other words, Mauro Balestra’s research approach makes it possible to say everything that happens during the driver’s reaction time, how long the reaction time is and how the person in the vehicle really reacts. The first results of the latest research series, carried out by Mauro Balestra together with the catholic university in Milan, are highly promising – and point to factors that have previously been ignored in safety planning.
In the vehicle: the entire measurement chain comes from HBM
The complexity of the measurement task was matched by the clear and well-defined demands that Mauro Balestra made of the measurement technology being used. It had to be reliable, easy to install, and suitable for tests in a moving vehicle. Which is why the engineer decided to deploy the entire HBM measurement chain. The U93 force transducer is used to record the force on the brake pedal, and a type WA displacement sensor is installed on the gas pedal of the vehicle.
Tacho-sensors and speed sensors from other manufacturers were also used, as well as video cameras to record the driver’s face muscles and the traffic situation.
Data acquisition is taken care of by a compact, universal QuantumX MX840A amplifier from HBM, mounted inside the test vehicle.
The PC’s Ethernet interface takes all the measurement data acquired by the QuantumX to the HBM measurement software, catman®AP. When they arrive, the data are not simply read in, they are also synchronized with the video footage from the passenger compartment.
It was not just its compact format that made the QuantumX the ideal choice, it was also the fact that it can be used with all current transducer technologies. Further plus points are its straightforward operation and the precision of the measurement data it collects. Because the transducers are fitted with the TEDS electronic data sheet, the QuantumX detects them automatically and they can be used for measurement immediately.
Simple to set up, professional in operation: whether on the move or integrating video files, the entire HBM measurement chain was always at its best. And revealing new discoveries to make driving in traffic safer.
Recording the measurement data
The data were recorded while driving.
A - Video monitoring
B - Driver’s view of the road (visibility range)
C - Danger simulation
D - Brake force measurement
E - Gas pedal displacement measurement
F - MX840A measurement electronics
G - Displacement, acceleration and speed measurement
H - Laptop
I - catman data recording software
Mon-Fri Test Week Measurements
Test subjects (vehicle drivers)
Test series situations (danger levels)
8 + 1 real danger
Duration of test series (minutes)
Test transducers and sensors
4 + time
Transmission and calculation channels
Speed of measurement (data/seconds)
Time results (Hz)
Data result per section (average)
Total values recorded
Video camera: color, HD
Frame rate (Hz)
HD Images received per section (average)
Total images recorded
"We have been using HBM measurement technology for over 30 years. With the QuantumX amplifier system and catmanEasy software, HBM was also able to offer us a viable and easy-to-install solution for our latest generation of tests." Mauro Balestra, Balestra CSR- Centro Studi e Ricerca.