2 The Basics

This section provides a brief introduction to the TRACER mobile robot platform, as shown in Figure 2.1 and Figure2.2.

Figure 2.2 Rear View

TRACER is Designed as a complete intelligent module, which along with powerful DC hub motor, enables the chassis of TRACER robot to flexibly move on flat ground of indoor. Anti-collision beams are mounted around the vehicle to reduce possible damages to the vehicle body during a collision.

Lights is mounted at front of the vehicle, of which the white light is designed for illumination in front.

An emergency stop switch is mounted at the rear end of vehicle body, which can shut down power of the robot immediately when the robot behaves abnormally.

Water-proof connectors for DC power and communication interface is provided at the rear of TRACER, which not only allow flexible connection between the robot and external components but also ensures necessary protection to the internal of the robot even under severe operating conditions.

A bayonet open compartment is reserved on the top for users.

2.1 Status indication

Users can identify the status of vehicle body through the voltmeter and lights mounted on TRACER. For details, please refer to Table 2.1.

Table 2.1 Descriptions of Vehicle Status

2.2 Instructions on electrical interfaces

2.2.1 Rear electrical interface

The extension interface at rear end is shown in Figure 2.3, where Q1 is D89 serial port; Q2 is the stop switch; Q3 is the power charging port; Q4 is the extension interface for CAN and 24V power supply; Q5 is the electricity meter; Q6 is the rotary switch as the main electrical switch.

Figure 2.3 Illustration Diagram of Q1 Pins

Figure 2.4 Illustration Diagram of Q4 Pins

The rear panel provides the same CAN communication interface and 24V power interface with the top one (two of them are internally inter-connected). The pin definitions are given in Figure 2.5.

Figure 2.5 Description of Rear Aviation Interface Pins

2.3 Instructions on remote control

FS RC transmitter is an optional accessory of TRACER for manually controlling the robot. The transmitter comes with a left-hand-throttle configuration. The definition and function as shown in Figure 2.6.

Figure 2.6 Schematic Diagram of Buttons on FS RC transmitter

In addition to the two sticks S1 and S2 used for sending linear and angular velocity commands, two switches are enabled by default: SWB for control mode selection (top position for command control mode and the middle position for remote control mode), SWC for lighting control. The two POWER buttons need to be pressed and held together to turn on or turn off the transmitter.

2.4 Instructions on control demands and movements

A reference coordinate system can be defined and fixed on the vehicle body as shown in Figure 2.7 in accordance with ISO 8855.

Figure 2.7 Schematic Diagram of Reference Coordinate System for Vehicle Body

As shown in Figure 2.7, the vehicle body of TRACER is in parallel with X axis of the established reference coordinate system. Following this convention, a positive linear velocity corresponds to the forward movement of the vehicle along positive x-axis direction and a positive angular velocity corresponds to positive right-hand rotation about the z-axis. In the manual control mode with a RC transmitter, pushing the C1 stick (DJI model) or the S1 stick (FS model) forward will generate a positive linear velocity command and pushing C2 (DJI model) and S2 (FS model) to the left will generate a positive angular velocity command.