Autonomous Mobile Robots and Multi-Robot Systems

3Motion in the Global Coordinates

Nir Shvalb and Shlomi Hacohen

This chapter considers the models of motion in global coordinates system (in two and three dimensions) such that the robot has complete information about the robot's location and velocity with respect to the origin. Such information is provided by permanent access to global positioning system or to hovering cameras. In particular, the chapter introduces the concept of configuration space and considers transformations of vehicle coordinates; turning radius, instantaneous velocity center, rotation, and translation matrices.

3.1 Models of Mobile Robots

3.1.1 Wheeled Mobile Robots

Numerous types of ground wheeled robots exist; we can roughly categorize them as follows, and shown in Figure 3.1a−f:

1. Car‐like vehicles
2. Bi‐wheeled vehicles
3. Tracked vehicles
4. Omni‐wheeled vehicles
5. Hilare‐type vehicles

Figure 3.1 Types of vehicles.

Car‐like vehicles (or robots) possess three or more wheels and are constructed with at least one steered axle. The motorized wheels are chosen to be standard (a standard wheel is one that is fixed to roll along a straight line path). The various car‐like designs differ from one another by the choice of the steered axle, usually the front axle (see Figure 3.1a) and the choice of the motorized wheels (front drive or rear drive).

Remark

When designing a car‐like vehicle, the set of considerations ...