Setup & Config

The OSCP ROS 2 driver is configured via a YAML file passed at launch time. All parameters are loaded at startup and sent to the IMU over serial before streaming begins.

Config Argument

ros2 launch oscp_imu_ros2 oscp_imu.launch.py config_file:=test.yaml

The config_file argument must point to a YAML file located in oscp_imu_ros2/config/.

YAML Structure (ex. default.yaml)

oscp_imu_node:
  ros__parameters:
    transport: "RS422"
    device: "/dev/ttyUSB0"
    baudrate: 921600
    frame_id: "imu_link"
    pub_accel_in_g: false

    operating_mode: "LOW"

    publish_standard_ros: True            # Default: True
    publish_oscp_raw: True                # Default: True
    publish_oscp_euler: False              # Default: False
    publish_oscp_quat: True               # Default: True
    publish_oscp_rotation_matrix: False    # Default: False
    publish_oscp_gnss: False               # Default: False

    watchdog_timeout_ms: 1000.0
    parser_stats_log_interval_s: 0.0

    gyro_range: "DPS_250"
    accel_range: "G_4"
    incl_range: "G_0_5"

    gyro_filter_mode: "DISABLED"
    gyro_lpf: "C0"
    gyro_hpf: "C0"

    accel_filter_mode: "DISABLED"
    accel_lpf: "C0"
    accel_hpf: "C0"

    ahrs_convention: "NWU"
    ahrs_heading_source: "NONE"

    misalignment: true

ROS Parameters

Transport

Value	Description
`RS422`	RS-422 serial communication
`CAN`	CAN communication

Device

Parameter	Type	Description
`device`	string	Serial port path
`baudrate`	int	Must be `921600` for RS-422 variants except in custom builds
`frame_id`	string	Frame ID used in all published messages
`pub_accel_in_g`	bool	If `true`, publish acceleration in g. If `false`, publish in m/s²

Operating Mode

Value	Output Data Rate
`IDLE`	0 Hz
`LOW`	100 Hz
`MEDIUM`	500 Hz

Output Frame Enables

Parameter	Type	Description
`publish_standard_ros`	bool	Publish `sensor_msgs/Imu`, `MagneticField`, `Temperature`
`publish_oscp_raw`	bool	Publish raw OSCP frame
`publish_oscp_quat`	bool	Publish quaternion OSCP frame
`publish_oscp_euler`	bool	Publish Euler angles OSCP frame
`publish_oscp_rotation_matrix`	bool	Publish rotation matrix OSCP frame

Warning

Enabling too many output frames simultaneously at MEDIUM (500 Hz) may cause controller overruns on the IMU. Refer to the IMU datasheet for guidance.

Watchdog and Parser Statistics

The watchdog monitors the time between successfully received IMU frames. If no valid frame is received within watchdog_timeout_ms, the node reports a communication timeout.

The parser statistics provide information about the received and processed IMU frames, including parser errors and packet-related statistics. They are useful for diagnosing serial communication and packet integrity issues.

parser_stats_log_interval_s controls logging only and does not affect the IMU's output rate or communication behavior.

IMU Configurations

Gyroscope Dynamic Range

Value	Range
`DPS_125`	±125 °/sec
`DPS_250`	±250 °/sec
`DPS_500`	±500 °/sec
`DPS_1000`	±1000 °/sec
`DPS_2000`	±2000 °/sec
`DPS_4000`	±4000 °/sec

Accelerometer Dynamic Range

Value	Range
`G_2`	±2 g
`G_4`	±4 g
`G_8`	±8 g
`G_16`	±16 g

Inclinometer Dynamic Range

Value	Range
`G_0_5`	±0.5 g
`G_1_0`	±1.0 g
`G_2_0`	±2.0 g
`G_3_0`	±3.0 g

Misalignment Correction

Parameter	Type	Description
`misalignment`	bool	Enables gyroscope and accelerometer misalignment correction

Gyroscope Filter

Parameter	Options	Description
`gyro_filter_mode`	`DISABLED`, `LP_ONLY`, `HP_ONLY`, `LP_AND_HP`	Filter mode
`gyro_lpf`	`C0` – `C7`	Low-pass cutoff selection
`gyro_hpf`	`C0` – `C3`	High-pass cutoff selection

Gyroscope Low-Pass Cutoff (gyro_lpf)

Value	Cutoff (Low ODR)	Cutoff (Medium ODR)
`C0`	33 Hz	222 Hz
`C1`	33 Hz	186 Hz
`C2`	33 Hz	140 Hz
`C3`	33 Hz	260 Hz
`C4`	34 Hz	96 Hz
`C5`	31 Hz	49 Hz
`C6`	19 Hz	25 Hz
`C7`	11.6 Hz	12.6 Hz

Gyroscope High-Pass Cutoff (gyro_hpf)

Value	Cutoff
`C0`	16 mHz
`C1`	65 mHz
`C2`	260 mHz
`C3`	1.04 Hz

Accelerometer Filter

Parameter	Options	Description
`accel_filter_mode`	`DISABLED`, `LP_ONLY`, `HP_ONLY`, `LP_AND_HP`	Filter mode
`accel_lpf`	`C0` – `C7`	Low-pass cutoff selection
`accel_hpf`	`C0` – `C7`	High-pass cutoff selection

Accelerometer Low-Pass and High-Pass Cutoff

Value	Cutoff (Low ODR)	Cutoff (Medium ODR)
`C0`	26 Hz	208.25 Hz
`C1`	10.4 Hz	83.3 Hz
`C2`	5.2 Hz	41.65 Hz
`C3`	2.3 Hz	18.5 Hz
`C4`	1.04 Hz	8.33 Hz
`C5`	0.52 Hz	4.17 Hz
`C6`	0.26 Hz	2.08 Hz
`C7`	0.13 Hz	1.04 Hz

AHRS Configuration

Parameter	Options	Description
`ahrs_convention`	`NWU`, `ENU`, `NED`	Earth axis convention for AHRS output frames
`ahrs_heading`	`NONE`, `INTERNAL_MAGNETOMETER`	Heading source used by the AHRS filter

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