Marie Curie - International Reintegration Grant# 239421

MIEDT: Modelling and Implementation of Expert Driving Techniques towards the Development of New Active Safety Systems for Passenger Vehicles

 

PI: Dr Efstathios Velenis, School of Engineering and Design, Brunel University

 

 

AIM

In this project we study driving techniques used by expert race drivers to control their vehicles under extreme operating conditions. We envision that expert driver knowledge can be modelled mathematically and implemented towards the development of a new generation of active safety systems for passenger vehicles. These new systems will employ expert driving skills to assist the driver, or autonomously control the vehicle close to the limit of its handling performance. In this project we focused on driving techniques used by rally-race drivers, who clearly operate beyond the limits enforced by current active safety systems. With the above vision in mind we set out to fulfil the following objectives:

 

·         Collect expert driver knowledge in the form of empirical guidelines on the execution of expert driving techniques used in rally racing, as well as in the form of driver control commands and vehicle response data during the execution of such expert driving techniques by race drivers.

·         Based on this newly acquired knowledge on rally driving techniques, design a control scheme, which uses driver control inputs (steering, throttle and brake commands), to reliably replicate the expert driving techniques recorded, and implement the control architecture in realistic simulation environments

 

 

 

FACILITIES & TESTING

·         Test Vehicle: 2006 Ford Fiesta ST (FWD, 2.0lt, 150bhp)

·         Racelogic Dual Antenna GPS Receiver (VB20SL) – velocity and sideslip measurement

·         Racelogic Base Station for Differential GPS corrections – position accuracy of 40cm

·         Racelogic CAN-Bus interface (CAN02) – collect engine speed, throttle position and 4 wheel speeds from OBDII connector

·         Racelogic IMU (IMU02) – 3 axis accelerations, 3 axis angular rates

·         Steering angle string potentiometer

·         Front and rear axle brake pressure sensors

·         Testing at Bill Gwynne rally school (www.billgwynne.com) – rally instructors performed a variety of techniques during data collection; additional vehicles from the rally school were instrumented and tested.

 

Test Vehicle during data collection

 

 

CONTROL DESIGN

·         Steady-state cornering conditions considering nonlinear tyre force characteristics and realistic drive-train constraints were numerically calculated.

·         A control architecture was designed to stabilise the vehicle with respect to cornering equilibria near the limit of handling (on or beyond the limit of tyre adhesion) using the same control authority as the human driver, namely steering-throttle-brake control inputs.

·         The control scheme consists of two layers:

In the first layer a linear quadratic regulator stabilises the vehicle using steering angle and wheel speed inputs.

In the second layer a back-stepping, or alternatively a sliding mode control, provides the drive/brake torque necessary to regulate the wheel speeds dictated by the first layer.

 

 

 

IMPLEMENTATION

·         The control architecture was implemented in a high-fidelity simulation environment (CarSim)

·         A variety of steady-state cornering conditions were tested including “drifting” equilibria at aggressive sideslip angles

·         Comparing simulation results with the collected data demonstrated that the controller acts in accordance to the expert driver

 

 

High-fidelity simulation of the stabilization of steady-state “drifting” along a 13m and a 2m turning radius.

Click on the images to view the animation.

 

 

PUBLICATIONS

[1] E. Velenis, E. Frazzoli and P. Tsiotras, “On Steady-State Cornering Equilibria for Wheeled Vehicles with Drift”, 48th IEEE Conference on Decision and Control, Shanghai, China, December 16-18, 2009.

 

[2] E. Velenis, E. Frazzoli and P. Tsiotras, “Steady-State Cornering Equilibria and Stabilization for a Vehicle During Extreme Operating Conditions”, International Journal of Vehicle Autonomous Systems, Special Issue on Autonomous and Semi-Autonomous Control for Safe Driving of Ground Vehicles, vol. 8, no. 2/3, pp. 217-241, 2010.

 

[3] E. Velenis, D. Katzourakis, E. Frazzoli, P. Tsiotras and R. Happee, “Stabilization of Steady-State Drifting for a RWD Vehicle”, 10th International Symposium on Advanced Vehicle Control, Loughborough, UK, August 22-26, 2010.

 

[4] D. Katzourakis, E. Velenis, D. Abbink, R. Happee and E. Holweg, “Race Car Instrumentation for Driving Behaviour Studies”, IEEE Transactions on Instrumentation and Measurement (accepted).

 

[5] A. Scacchioli, J. Lu, P. Tsiotras and E. Velenis, “Accident Avoidance Using Electronic Posture Control Through Differential Braking”, 22nd International Symposium on Dynamics of Vehicles on Road and Tracks, Manchester Metropolitan University, Manchester, UK, August 14-19, 2011 (accepted).

 

[6] D. Katzourakis, E.Velenis and R. Happee, “Driver Control Actions in High Speed Circular Driving”, Driving Assessment Conference, Olympic Valley-Lake Tahoe, CA, USA, June 27-30, 2011 (accepted).