autoware_mrm_steering_hold_stop_operator

Overview

The autoware_mrm_steering_hold_stop_operator publishes the control command of an in-lane stop MRM that does not depend on any planner or trajectory follower. When the MRM is triggered, it holds the steering angle measured at the MRM start and stops the vehicle with a constant-jerk deceleration computed open-loop from the measured velocity and acceleration.

It subscribes to the same InLaneStopTrigger as the in-lane MRM planner, so it can be used as an alternative publisher of the in-lane stop command source of the control command gate.

• Trigger OFF: mirrors the measured vehicle state (steering, velocity, and acceleration clamped to <= 0) on its own timer, so that the gate input is alive and continuous before the gate switches to it.
• Trigger ON: latches the measured steering angle, velocity, and acceleration, then decelerates open-loop with the target_jerk down to the target_acceleration of the requested profile. The output continues after the velocity reaches zero.
• Required inputs stale: publishes nothing so that the input timeout of the control command gate escalates to its fallback, and reports the reason on ~/debug/status and the error log.

Note that holding the steering angle does not guarantee that the vehicle stays in its lane.

State machine

State	Condition	Output
MIRROR	trigger OFF and required inputs are fresh	measured state
WAITING_INPUT	required inputs are stale before the deceleration	none
DECELERATING	trigger ON and initialized from the fresh inputs	held steering + constant-jerk deceleration

• The required inputs are steering_status and kinematic_state. acceleration is also required at or above low_speed_threshold.
• Once DECELERATING, the deceleration continues even if the inputs become stale.
• Below low_speed_threshold, the acceleration measurement is not used and the deceleration starts directly at target_acceleration.
• A profile change while the trigger is ON updates only the targets. The held steering angle is kept.
• Trigger OFF returns to MIRROR. The next trigger latches the measurements again.

Deceleration profiles

The deceleration constraints are owned by this node as parameters per InLaneStopTrigger profile.

InLaneStopTrigger::profile	Parameters used
PROFILE_MODERATE	profiles.moderate
PROFILE_EMERGENCY	profiles.emergency
others (PROFILE_UNKNOWN)	profiles.moderate with an error log

An unknown profile still decelerates, because not stopping is more dangerous than stopping with the moderate constraints.

Interfaces

Input

Name	Type	Description
~/input/trigger	tier4_system_msgs/msg/InLaneStopTrigger	in-lane stop trigger and deceleration profile (reliable, transient_local, depth 1)
~/input/steering_status	autoware_vehicle_msgs/msg/SteeringReport	measured steering angle
~/input/kinematic_state	nav_msgs/msg/Odometry	measured velocity
~/input/acceleration	geometry_msgs/msg/AccelWithCovarianceStamped	measured acceleration

The trigger is transient_local, so a node restarted during the MRM receives the latest trigger and continues to decelerate. In that case the steering angle is latched again from the measurement after the restart.

Output

Name	Type	Description
~/output/control	autoware_control_msgs/msg/Control	control command for the gate input
~/debug/status	autoware_internal_debug_msgs/msg/Float32MultiArrayStamped	internal state (see below)

~/debug/status layout:

Index	Content
0	state (0: MIRROR, 1: WAITING_INPUT, 2: DECELERATING)
1	trigger (1: ON, 0: OFF)
2	age of steering_status [s] (-1: never received)
3	age of kinematic_state [s] (-1: never received)
4	age of acceleration [s] (-1: never received)
5	held steering angle [rad]
6	commanded velocity [m/s]
7	commanded acceleration [m/s^2]
8	target acceleration of the resolved profile [m/s^2]
9	target jerk of the resolved profile [m/s^3]
10	received InLaneStopTrigger::profile

Parameters

Name	Type	Description	Default	Range
update_rate	float	Output period of the control command [Hz]	33.3	>0.0
input_freshness_timeout	float	Allowed age of steering_status / kinematic_state / acceleration [s]	0.5	>0.0
low_speed_threshold	float	Below this speed the acceleration measurement is not used and the deceleration starts directly at target_acceleration [m/s]	1	≥0.0
profiles.moderate.target_acceleration	float	Target acceleration of the constant-jerk deceleration [m/s^2]		≤0.0
profiles.moderate.target_jerk	float	Target jerk of the constant-jerk deceleration [m/s^3]		≤0.0
profiles.emergency.target_acceleration	float	Target acceleration of the constant-jerk deceleration [m/s^2]		≤0.0
profiles.emergency.target_jerk	float	Target jerk of the constant-jerk deceleration [m/s^3]		≤0.0