fix lift runstop drop and adjust homing sensitivity

[aedsinger]

This fixes an issue where the lift would drop when runstopped. The new cancel routine functions were exiting the homing routing prior to resetting the stiffness and other controller params, that are temporarily modified during homing. This logic is now correct.

In addition, on 4032 the homing contact would false positive when started very low. Decreased the sensitivity and tested thoroughly. Should be tested on other robots.

[hello-robot-shehab]

Thank you for the cancel homing fix Aaron!

[hello-bharadwaj]

Test 1: stretch_lift_home -d FAIL

Tested once: Lift started homing and i runstopped midway and the left fell. [I had a clamp so crash was avoided]

hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_lift_home -d
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:23:55] [lift] [INFO]: Starting Lift...
Starting transmit_q thread: /dev/hello-motor-lift
Homing Lift...
[06/18/2026 17:24:11] [lift] [WARNING]: Lift homing failed. Failed to detect contact
[06/18/2026 17:24:12] [hello-motor-lift] [INFO]: Shutting down Stepper on: /dev/hello-motor-lift
Shutting down transmit_q thread /dev/hello-motor-lift

Test 2: stretch_body_server --launch in terminal 1 and stretch_lift_home in terminal 2 PASS

Tested thrice: Lift started homing and i runstopped midway and the lift didnt move.

hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_lift_home
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:26:13] [lift] [INFO]: Homing lift...
[06/18/2026 17:26:15] [lift] [ERROR]: Failed to home joint lift.
hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_lift_home
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:26:34] [lift] [INFO]: Homing lift...
[06/18/2026 17:26:37] [lift] [ERROR]: Failed to home joint lift.
hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_lift_home
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:26:46] [lift] [INFO]: Homing lift...
[06/18/2026 17:26:48] [lift] [ERROR]: Failed to home joint lift.
hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_lift_home
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:26:57] [lift] [INFO]: Homing lift...
[06/18/2026 17:27:05] [lift] [INFO]: Successfully homed lift.

[hello-bharadwaj]

Test 3: stretch_body_server --launch in terminal 1 and stretch_robot_home in terminal 2 PASS

Tested thrice: Started robot homing,, lift startd moving and i runstopped midway and the lift didnt move

hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_robot_home 
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:29:20] [robot] [INFO]: Starting robot homing routine
[06/18/2026 17:29:23] [robot] [ERROR]: Homing routine timed out before completion.
hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_robot_home 
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:29:36] [robot] [INFO]: Starting robot homing routine
[06/18/2026 17:29:38] [robot] [ERROR]: Homing routine timed out before completion.
hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_robot_home 
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:29:51] [robot] [INFO]: Starting robot homing routine
[06/18/2026 17:29:53] [robot] [ERROR]: Homing routine timed out before completion.
hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_robot_home 
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:30:03] [robot] [INFO]: Starting robot homing routine
[06/18/2026 17:30:35] [robot] [INFO]: Homing routine ended.

Test 4: stretch_robot_home -d FAIL

Tested thrice: Started robot homing,, lift started moving and i runstopped midway and there were two different behaviours.

1. Before the lift was past midway it fell a little and stopped itself.
2. After the lift was past midway and closing towards head, it fell directly down to the clamp.

In both cases, the homing script will fail to home lift but continue to home the arm and eoa.

hello-robot@stretch-se4-4034:~/repos/stretch4_body$ stretch_robot_home -d
For use with S T R E T C H (R) from Hello Robot Inc.
---------------------------------------------------------------------

[06/18/2026 17:34:42] [robot] [INFO]: Starting up Robot stretch-se4-4034 of batch francis
[06/18/2026 17:34:42] [lift] [INFO]: Starting Lift...
Starting transmit_q thread: /dev/hello-motor-lift
[06/18/2026 17:34:42] [arm] [INFO]: Starting Arm...
Starting transmit_q thread: /dev/hello-motor-arm
[06/18/2026 17:34:42] [omnibase] [INFO]: Starting Omnibase...
Starting transmit_q thread: /dev/hello-motor-omni-0
Starting transmit_q thread: /dev/hello-motor-omni-1
Starting transmit_q thread: /dev/hello-motor-omni-2
[06/18/2026 17:34:42] [power_periph] [INFO]: Starting PowerPeriph...
Starting transmit_q thread: /dev/hello-power-periph
[06/18/2026 17:34:42] [wrist_pitch] [INFO]: Starting Wrist_pitch...
[ID:021] ping Succeeded. SCServo model number : 10504
[06/18/2026 17:34:42] [wrist_roll] [INFO]: Starting Wrist_roll...
[ID:022] ping Succeeded. SCServo model number : 10504
[06/18/2026 17:34:42] [wrist_yaw] [INFO]: Starting Wrist_yaw...
[ID:020] ping Succeeded. SCServo model number : 10504
[06/18/2026 17:34:42] [stretch_gripper] [INFO]: Starting Stretch_gripper...
[ID:023] ping Succeeded. SCServo model number : 10504
[06/18/2026 17:34:42] [robot] [INFO]: --------- Homing Lift ----
Homing Lift...
[06/18/2026 17:34:57] [lift] [WARNING]: Lift homing failed. Failed to detect contact
[06/18/2026 17:34:58] [robot] [INFO]: --------- Homing Arm ----
Homing Arm...
[06/18/2026 17:34:59] [arm] [INFO]: Hardstop detected at motor position (rad) 0.09569639712572098
[06/18/2026 17:34:59] [arm] [INFO]: Marking Arm position to 0.0 (m)
[06/18/2026 17:35:01] [arm] [INFO]: Arm homing successful
[06/18/2026 17:35:01] [robot] [INFO]: --------- Homing EndOfArm ----
[06/18/2026 17:35:02] [wrist_yaw] [INFO]: Moving to first hardstop (wrist_yaw)...
^CCaught signal 2