odom_dataset / metadata /tof_sensor.md
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TOFSense-M ToF Sensor Metadata

Language: English | 简体中文

The dataset ToF topic is /nlink_tofsensem_cascade. It records a six-node Nooploop TOFSense-M cascade using UART query output in 8x8 mode.

Collection Configuration

Field Value
Sensor model Nooploop TOFSense-M
Sensor type Time-of-flight matrix laser ranging sensor
ROS topic /nlink_tofsensem_cascade
ROS message nlink_parser/TofsenseMCascade
Interface UART
Output mode Query
Cascade nodes 6
Pixel mode 8x8
Pixels per node 64
Expected pixels per cascade message 384
Nominal refresh rate 15 Hz per node in 8x8 mode
UART baud rate 921600 bps

Message Layout

nlink_parser/TofsenseMCascade contains nodes, an array of nlink_parser/TofsenseMFrame0.

Each node has:

Field Type Meaning
id uint8 Module ID in the cascade
system_time uint32 Sensor-side system time
pixel_count uint8 Expected to be 64 in this dataset
pixels TofsenseMFrame0Pixel[] Pixel data ordered from index 0 to 63

Each pixel has:

Field Type Unit Meaning
dis float32 mm Distance decoded by the current nlink_parser output
dis_status uint8 code Per-pixel distance status
signal_strength uint16 raw count Return signal strength; larger is stronger

For validity checks, treat a pixel as usable only when dis_status == 0 and dis > 0.

Distance Status Codes

Code Meaning
0 Measurement usable
1 Signal strength too low
2 Phase target
3 Target noise estimate too high
4 Target consistency check failed
5 Measurement not updated
6 Wraparound not performed, usually the first measurement
7 Rate inconsistent
8 Current target signal strength low
9 Large pulse valid range, possibly due to merged targets
10 Usable measurement, but no target was detected in the previous detection
11 Measurement inconsistent
12 Target ambiguous
13 Target detected but data inconsistent, usually when a secondary target exists
255 Target not detected

Sensor Specifications

Parameter Value
Range at 600 lux 1.5 cm to 4 m
Range at 60K lux 1.5 cm to 2 m
Range at 100K lux 1.5 cm to 1.2 m
Distance resolution 1 mm
Typical ranging accuracy +/- 1.5 cm
Typical standard deviation < 1 cm at 4 m indoors / 600 lux
Field of view 45 deg horizontal, 45 deg vertical, 65 deg diagonal
Supported pixel modes 8x8 and 4x4
Refresh rate 15 Hz at 8x8, 60 Hz at 4x4
Laser wavelength 940 nm
Laser class Class 1
Typical power 670 mW
UART supply voltage 3.7 V to 5.2 V
CAN supply voltage 4.2 V to 5.2 V

The fixed ToF-to-base extrinsic is not available in this dataset version. Use calibration/robot_v1_template/tof_to_base.yaml for the explicit calibration status.