Acceleration behaviour

[jmartherose-aldebaran]

Hello,

We've been using the swd_ros2_controller to run our robot equipped with two (left and right) ezWheels with ROS2, and we're observing a behavior where it appears that the time to reach a given speed is constant, no matter the final speed we're trying to achieve, rather than being dependent on time.

For example:

• if we're trying to go at 0.5m/second, the robot will take ~7 second to reach the target speed
• if we're trying to go at 1.5m/second, the robot will take ~7 second to reach the target speed

Is it possible to change it so that instead, we'd have something like:

• if we're trying to go at 0.5m/second, the robot will take ~3.5 seconds to reach the target speed
• if we're trying to go at 1m/second, the robot will take ~7 seconds to reach the target speed

(Which I IIRC is the default behavior expected by ROS navigation-related plugins)

The parameters related to the velocity mode / ramp behavior have been left to default because we're unsure on how to modify them.

Thank you for your help.

[ez-Support]

Hello,

According to your SWD gear ratio .4,
You can test to decrease the acceleration ramps as follow, so the robot will accelerate more slowly:

vl_acc_delta_speed = 100  # 1500
vl_dec_delta_speed = 500  # 1500 (For decelleration, maybe you leave them as they were)

For both wheels in the commissioning:
https://github.com/ezWheelSAS/swd-starter-kit-config/blob/main/commissioning/swd_left_4_commissioning.py#L95
https://github.com/ezWheelSAS/swd-starter-kit-config/blob/main/commissioning/swd_right_5_commissioning.py#L95

[jmartherose-aldebaran]

Thank you for the answer, I will try these parameters ASAP and report back here with the results.