TRACER provides CAN interface for user customization. Users can use it to conduct command control over the vehicle body.

TRACER adopts CAN2.0B communication standard which has a communication baud rate of 500K and Motorola message format. Via external CAN bus interface, the moving linear speed and the rotational angular speed of chassis can be controlled; TRACER will feedback on the current movement status information and its chassis status information in real time.

The protocol includes system status feedback frame, movement control feedback frame and control frame, the contents of which are shown as follows:

Table of Contents

The system status feedback command includes the feedback information about current status of vehicle body, control mode status, battery voltage and system failure. The description is given in Table 3.1.

1. System Status

| Command Name | System Status Feedback Command |

|

| | | --- | --- | --- | --- | --- | |   Sending node |   Receiving node |   ID | Cycle (ms) | Receive- timeout (ms) | | Steer-by-wire chassis | Decision-making control unit |   0x211 |   20ms |   None | | Data length | 0x08 |   |   | | | Position | Function | Data type | Description | | |     byte [0] |   Current status of vehicle body |     unsigned int8 | 0x00 System in normal condition 0x01 Emergency stop mode 0x02 System exception | | |     byte [1] |     Mode control |     unsigned int8 | 0x00 Standby mode 0x01 CAN command control mode 0x02 Remote control mode | | |     byte [2] byte [3] | Battery voltage higher 8 bits Battery voltage lower 8 bits |     unsigned int16 |   Actual voltage X 10 (with an accuracy of 0.1V) | | |   byte [4] | High 8 digits of fault information |     unsigned int16 |     See notes for details【 Table 3.2】 | | |   byte [5] | Low eight bits of fault information | | | | | byte [6] | Reserved |

| 0x00 | | |   byte [7] | Count paritybit (count) |   unsigned int8 |   0 - 255 counting loops | |

2. Failure Information

Table 3.2 Description of Failure Information

bit [0] | Battery under-voltage failure (0: No failure 1: Failure) Protective voltage 22V | | |   bit [1] | Battery under-voltage alarm (0: No alarm 1: Alarm) Alarm voltage 22.5V | | |   bit [2] | RC transmitter disconnection protection (0: Normal 1: RC transmitter disconnected) | | | bit [3] | Motor driver 1 lost connection | | | bit [6] | Motor driver 2 lost connection | | | bit [7] | Reserved | | byte [5] | bit [0] | Motor driver abnormality | | | bit [1:7] | Reserved |

3. Movement Control Feedback Frame

The command of movement control feedback frame includes the feedback of current linear speed and angular speed of moving vehicle body. For the detailed content of protocol, please refer to Table 3.3.

Table 3.3 Movement Control Feedback Frame

| Command Name | Movement Control Feedback Command | | | | | --- | --- | --- | --- | --- | |   Sending node |   Receiving node |   ID |   Cycle (ms) | Receive-timeout (ms) | | Steer-by-wire chassis | Decision-making control unit |   0x221 |   20ms |   None | | Data length | 0x08 |   |   | | | Position | Function | Data type | Description | | |     byte [0] byte [1] | Moving speed higher 8 bits Moving speed lower 8 bits |     signed int16 |     Vehicle speed Unit：mm/s | | |       byte [2] byte [3] | Rotational speed higher 8 bits Rotational speed lower 8 bits |       signed int16 |     Vehicle angular speed Unit： 0.001rad/s | | | byte [4] | Reserved |

| 0x00 | | | byte [5] | Reserved |

| 0x00 | | | byte [6] | Reserved |

| 0x00 | | | byte [7] | Reserved |

| 0x00 | |

4. Movement Control Command

The control frame includes control openness of linear speed and control openness of angular speed. For its detailed content of protocol, please refer to Table 3.4.

Table 3.4 Control Frame of Movement Control Command

Sending node |   Receiving node |   ID |   Cycle (ms) | Receive-timeout (ms) | | Steer-by-wire chassis | Decision-making control unit |   0x111 |   20ms |   500ms | | Data length | 0x08 |   |   | | | Position | Function | Data type | Description | | |   byte [0] byte [1] | Moving speed higher 8 bits Moving speed lower 8 bits |     signed int16 |   Vehicle speed Unit：mm/s Effective value±1800 | | |   byte [2] byte [3] | Rotational speed higher 8 bits Rotational speed lower 8 bits |     signed int16 |   Vehicle angular speed Unit：0.001rad/s Effective value±1000 | | | byte [4] | Reserved | — | 0x00 | | | byte [5] | Reserved | — | 0x00 | | | byte [6] | Reserved | — | 0x00 | | | byte [7] | Reserved | — | 0x00 | |

5. Lighting Control Frame

The light control frame includes current state of front light. For its detailed content of protocol, please refer to Table 3.5.

Table 3.5 Lighting Control Frame

| Command Name | Command Name Lighting Control Frame | | | | | --- | --- | --- | --- | --- | |   Sending node |   Receiving node |   ID |   Cycle (ms) | Receive-timeout (ms) | | Steer-by-wire chassis | Steer-by-wire chassis |   0x121 |   25ms |   500ms | | Data length | 0x08 |   |   | | | Position | Function | Data type | Description | | |   byte [0] |   Lighting control enable flag |   unsigned int8 | 0x00 Control commandinvalid   0x01 Lighting control enable | | |     byte [1] |     Front light mode |     unsigned int8 | 0x00 NC 0x01 NO 0x02 BL mode 0x03 User-defined brightness | | |   byte [2] | Custom brightness of front light |   unsigned int8 | [0,100],where 0 refers to no brightness, 100 refers to maximum brightnes【5】 | | | byte [3] | Reserved |

| 0x00 | | | byte [4] | Reserved |

| 0x00 | | | byte [5] | Reserved |

| 0x00 | | | byte [6] | Reserved |

| 0x00 | | |   byte [7] | Count paritybit (count) |   unsigned int8 | 0

• 255 counting loops, which will be added once every command sent | |

<aside> 💡 Note[5]: This date only valid in custom mode The light control frame includes light control mode and control openness. For its detailed content, please refer to Table 3.6.

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