1. State and Parameter Estimation of
Vehicle Dynamics for Navigation and
Sideslip
Fargham Sandhu
PM Dr.Hazlina Binte Selamat
2. GPS Availability and Precision:
GPS availability availability has been questionable since its
creation . Features like Selective Availability have been used to
provide data to only specific locations.
GPS Accuracy provided to general purpose use is not better then
10m due to intentional inaccuracies by (USDoD).
GPS problems in built-up areas and tunnels has always been a
problem due to direct line of sight (LOS) requirement.
Remedy:
To have owned a satellite based navigational system.
Develop GPS free navigational systems.
Problem Statement
3. Design Vehicular Navigational System
That does not depend on GPS data for navigation.
Helps in creating high resolution enhanced
magnetometer-distance charts for complex road layout.
Helps in providing directions in underground roads to
novice drivers.
Research Objectives
4. Study how to create GPS free navigational system
with same or better accuracy than the GPS version.
Create and implement Enhanced magnetometer
based global mapping system.
Use some sort of low dependency GPS solution for
improving the navigational results.
Scope of Study
7. Navigation of vehicle:
Bearing (Heading) of Reference Point
Satellite Angles w.r.t to the Receiver(GPS)
Magnetic North and South pole (Digital Compass)
Distance from Reference point
Distances of each satellite from the Receiver
Distance from Equator and north and south pole.
Navigation
8. Global Navigation
Location of vehicle from the equator or north/south pole and heading in which
direction
Method: Using GPS and Global mapping system or Using magnetometer
with enhanced global map.
Requirement: To globally determine the location of vehicle
Local Navigation
e.g Distance of car from meranti and is travelling in which direction.
Method: using inertial measuring system and incorporating the vehicle
dynamics to find the exact distance travelled and the exact bearing.
Requirement: To assist the driver to reach destination without any required
knowledge of the place.
Vehicular Navigation
9. Lateral slippage of the vehicle due to the loss of friction in
vehicle tires is called sideslip. (β = aTan (Vy / Vx))[10][9][11]
Sideslip can cause heading errors and vehicular instability
when road surface has low friction coefficient.
Higher sideslip results in inaccurate speed estimation
causing false distance travelled. [11]
Requirements:
For both local and global navigation heading errors must be
reduced.
Accurate estimation of distance travelled is required for local
navigation.
Sideslip and Its Requirements
10. Installation of low cost INS system and integration
with barometric pressure sensor and magnetometer
for inertial forces, height and heading measurements
Experimental Setup
Driver Assist
On-board
Computer
Sensor Module
11. Bicycle Model [11]:
Applying longitudinal and lateral Dynamics we get:
Vehicle Model Dynamics
12. All parameters of the vehicle cannot be measured[11][].
State and Parameter Estimation
13. Using Inertial measurement Unit (IMU)[11][4]
Parameter Measurement
Speed Encoders in each wheel measure the speed of each
wheel(Vω)
Steering encoder measures the steering angle input (δ).
14. Lateral velocity can be estimated by using the appropriate
tyre model and vehicle dynamics. [9]
Sideslip can be estimated by using the lateral velocity and
horizontal velocity estimate or measurement.
Solution to the above equation is possible through
Recursive Least Square (RLS)[3] or Kalman Filter(KF) or non-
Linear observer like particle filter (PF)[12]
Lateral velocity and Sideslip
Estimation
