Establishment of a Safety-Preserved Estimation and

Control of Tire/Road Interaction

By Diala Uchenna

OutlineIntroductionObjectivesDesign procedureImplementationResultsConclusion

IntroductionTire/road interaction plays an important role for safe

operation of motor vehicles. The research involves the development, implementation,

and evaluation of a safety-preserved tire/road interaction estimation and control scheme.

The approach of this research is based on the integration of the physical and dynamic tire/road friction models with the distributed tire rubber deformation sensing system.

Based on the sensor-enabled models, on-line estimation and control strategies will be developed to predict the safety limits of tire/road interaction and prevent vehicles from unsafe operation. (Using Model Predictive Control)

ObjectivesThe following three objectives were sought:

a sensor-enabled tire/road interaction Modelling scheme This involved Modelling the Traxxas X0-1 (a Radio

Controlled-RC Car) with the CarSim application as well as the operating/testing environment.

ObjectivesThe following three objectives were sought:

a sensor-enabled tire/road interaction Modelling scheme This involved Modelling the Traxxas X0-1 (a Radio

Controlled-RC Car) with the CarSim application as well as the operating/testing environment.

a tire/road interaction safety-limit estimation and control system This involved designing a controller using the NI

LabVIEW application and myRIO hardware device.

ObjectivesThe following three objectives were sought:

a sensor-enabled tire/road interaction Modelling scheme This involved Modelling the Traxxas X0-1 (a Radio

Controlled-RC Car) with the CarSim application as well as the operating/testing environment.

a tire/road interaction safety-limit estimation and control system This involved designing a controller using the NI

LabVIEW application and myRIO hardware device.research/education integration.

Involving industrial applications and further collaboration with industry.

Design procedureThis involved three stages:

Modelling of the Traxxas X0-1 (RC Car) as well as its test environment with the CarSim application.

Design of the Control strategies with the LabVIEW application and myRIO hardware (On-going).

Integration of the CarSim models in the LabVIEW application for control and measurement operations (On-going).

Design procedure contd…Applications employed during the study

CarSim Software tool used globally by OEMs, suppliers, racing

teams, universities and students to simulate the dynamic behavior of four-and three-wheeled vehicles including cars, race cars, light trucks, light utility vehicles and SUVs.

Predicts the performance of vehicles in response to driver control inputs (steering, throttle, brakes, clutch, and shifting) in a given environment (road geometry, coefficients of friction, wind).

Performance implies vehicle motions, forces, and moments involved in acceleration, handling, and braking.

LabVIEW Stands for Laboratory Virtual Instrumentation Engineering

Workbench, is a graphical computing environment for instrumentation, system design, and signal processing.

NI myRIO is an embedded hardware device designed specifically to enable the design of real, complex engineering systems more quickly.

Design procedure contd…Stage 1

Modelling the Traxxas X0-1 Vehicle Body Suspensions Tyres Powertrain

Modelling the test environment 3D Road geometry and friction Wind & aerodynamic effect

Design procedure contd…The Traxxas X0-1

Design procedure contd…Anatomy of the Traxxas X0-1

Design procedure contd… Vehicle Body

Designed with 3D Max Studio Requires Sprung mass measurements and its coordinate system

Design procedure contd…Suspension

Camber and toe-in settings (Front and rear settings) Spring- ride heights, shock distance , rate etc.

Design procedure contd…Suspension

Camber and toe-in settings (Front and rear settings)

Design procedure contd…Tyres

Spring- ride heights, shock distance , rate and and lookup table etc.

Tyre width, unloaded tyre radius, effective rolling radius.

Design procedure contd… Powertrain

Engine, differential, torque converter and transmission . Electric Powertrain model required …not combustion engine.

Design procedure contd…Powertrain

CarSim’s generic features are highly focused on conventional powertrain systems, engine-torque converter-transmission-differential gear-wheel.

To simulate an in-wheel EV, a motor is modelled in Simulink or LabVIEW and inserted into the CarSim application.

Design procedure contd…Powertrain

The External engine model is used to link up to the collaborating application (LabVIEW).

The imported model replaces the engine block.

Design procedure contd…Modelling the test environment

3D Road geometry and friction Wind & aerodynamic effect

CarSim generic specifications and lookup tables

Design procedure contd…Stage 2

Design of the Control strategies with the LabVIEW application and myRIO hardware

Sample vi showing collaboration.

Design procedure contd…NI myRIO hardware device

To run in HIL, the system model receives measured variables from the myRIO device.

This hardware in turn receives calculated variables from the math model.

ImplementationThe control algorithm will be embedded on the NI myRIO

device via the LabVIEW software.The NI myRIO will be mounted on the Traxxas X0-1 and

function as the logic unit.An iphone will be used as the handheld controller for the

Traxxas X0-1.Communication between the iphone and the Traxxas X0-

1 will be Wireless (myRIO has a wireless feature).Sensors will be attached to the tyres to obtain required

variable measurements for analysis.Measured data will be fed back (Closed loop) to the

controller to compare with the desired system variable to be controlled.

Operating conditions of the dynamic system are altered to obtain desired set points.

ResultsA model (not for an Electric Powertrain) was developed

with specifications of the Traxxas X0-1.A simulation as well as an animation of the model was run.

ConclusionDue to time constraint, a model of the Traxxas

X0-1 (with an engine powertrain) was developed.

This may not represent the model accurately since an electric powertrain is employed.

Further study is on-going on the research and hopefully better results will be achieved.

Thank you