Mechanical Brake Torque

Advantages of EV

Original EV FPEV2-Kanon

Front In-wheel motor

Rear In-wheel motor

Configuration of FPEV2-Kanon

Vehicle stability control

Transfer function of half car model from pitching moment to angle

KCsIsM

2

1

Half car model x

rrffa

KCsIs

llmmh

2

)tan)1(tan(2

Parameters Identification Test

Plant model

Anti-dive and anti-lift force

Pitch angle

2DOF Control System

Real Plant

Ax

Ax Pn(s)

P(s)

s

s

C2

C1

xa

xna n n

mnT

mT

bT̂

bT e

*

Feedforward input (Ideal control input to Nominal Plant)

Feedback input (attenuates error caused by modeling error and disturbance)

Reference acceleration

Pitching control

Modeling of pitching motion

Pitch-rate Pitching angle (zoom) Motor torque

Both pitch-rate and pitch-angle are suppressed well. Pitching control start

Braking Distance

Vehicle comfort enhancement

Engine Electric motor

Torque response A few hundreds ms A few ms

Individual control Heavy and big: Impossible Light and small: possible

Measurable torque Nonlinear: Difficult Proportional to current: Easy

Electric vehicle

Improvement of mileage per charge Range extension control system (RECS)

Yaw-rate and slip-angle control based on lateral force sensor and active front steering

T

r

J

m

drFTdt

dJ

Motion equation of wheel

Driving force which is generated by tire can be estimated from above equation by computer.

Fd :Driving force

Angular acceleration →measurable by angular velocity sensor

Motor torque →measurable by current sensor

Inertia of wheel →constant

Non-driving wheel speed

Integration of the acceleration sensor

Optical sensor

Detection methods of vehicle speed

Braking force works to all wheels

No non-driving wheels on decelerating

The integration value diverges

It is expensive and not practical

Slip-ratio estimation without vehicle speed

Traction control based on slip ratio control

•Differentiating

•Substituting right

equations

Acceleration

Vehicle speed is calculated

Wheel speed reference is calculated

Wheel speed control Slip ratio

is estimated

Vehicle motion becomes unstable

There are risks of Side slip and spin

Maximum braking force around optimum slip ratio

Braking distance is shortened

Left slip ratio Right slip ratio

With

ou

t con

trol

With

con

trol

Vehicle velocity,

wheel velocity

(left)

Vehicle velocity,

wheel velocity

(right)

Deceleration

The slip ratio is defined by the wheel speed and vehicle speed.

It is very important value for control.

Experimental results

w/o parameter variance w/ parameter variance

(a) Decoupling control

(b) LFO+YMO LFO: Lateral force observer

YMO: Yaw-moment observer

Side-slip angle is the angle between longitudinal and lateral velocity.

Yaw-rate is angular velocity around the center of axis. Both the side-slip angle and yaw-rate

are affected by two control inputs

We want to control side-slip angle and yaw-rate independently by front active steering and

driving force difference

Decoupling control Disturbance observer called LFO+YMO The control laws of two control inputs:

Side-slip angle and yaw-rate are nominalized by LFO and YMO

Try to enhance the cruising range of EV’s by control technologies (Assumption: EV are installed multiple motors)

Battery Inv. 1

Inv. 4

M1

M4

…

… Vehicle

V

RECS I RECS II

RECS III

Same acceleration Driving force

<RECS1>

<RECS2>

Front motor efficiency map Rear motor efficiency map

Cornering resistance Driving force

<Conventional> <Proposed>

c pc p

The sum of the torque only needs to satisfy the driver demands.

Torque values have several degrees of freedom

Improve the overall efficiency by controlling each driving force

Cornering resistance is reduced by the yaw-moment generated by the torque difference

between left and right motors

FPEV3-coms long

MSHub

Pitching control

Atomic Force Microscope

Nano-stage

Hard Disc Drive Galvano Scanner Ball-screw Drive Stage

We approach next generation nano-scale technology by advanced motion control. ■AFM & HDD : High-speed and high-precision positioning are achieved by perfect tracking control theory and iterative learning control. ■Galvano scanner : High-speed positioning is investigating for three-mass system. ■Ball-screw drive stage : Nonlinear friction is compensated by novel friction compensation which is data based feedforward control. ■Nano-stage : High-bandwidth is achieved by using multi-sensor output.

Position Error

Conventional Proposed

w/ ctr. w/o ctr.

High speed current control for PMSM under voltage limit

Torque Ripple Suppression for PMSM

Motor benches & inverters

Powerelectronics

Torque ripple

Noise

Vibration

Problem

Arbitrary Inverter Output Voltage Generation by Multi-rate PWM

Perfect tracking control method (PTC) based on multi-rate PWM can achieve high

performance.

w/ AF installed RPTC w/o AF

Active Filter (AF) High speed position control

based on multi-rate PWM

Nanoscale Servo Control

Regenerative Brake and Slip Angle Control of Electric Vehicle for Safety Driving Hiroshi Fujimoto (fujimoto@k.u-tokyo.ac.jp)

High road

Low road