9. Navigation and control system
MiR1000 Shelf Lift User Guide (en) 12/2020 - v.2.1 ©Copyright 2019-2020: Mobile Industrial Robots A/S.
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The robot does not compare the laser scanner data with the entire map, but only around
the area that it expects to be close to based on the IMU and encoder data and its initial
position. This is why it is important that the initial position you place the robot at on the
map is accurate.
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The robot can drive for a short distance without being correctly localized. As it drives, the
estimated positions should converge to a small area, indicating the robot has determined
an accurate estimate. If this does not occur within a set time limit, the robot reports a
localization error.
9.7 Motor controller and motors
The robot keeps adjusting how much power is sent to each motor based on sensory
input. This means the robot can correct its speed when going up slopes or when carrying a
heavier payload, and it can change its driving direction to avoid moving obstacles.
9.8 Brakes
Once the approximated position of the robot determined from localization is the same as the
goal position calculated by the global planner, the robot stops by using the dynamic brake
function.
Figure 9.12. The robot has reached the goal position and stops by engaging the dynamic brake function.
The dynamic brake function stops the robot by short circuiting the power that was used to
rotate the motor. When this happens, the power that was used to drive the robot forward is
now reversed to stop the rotation of the drive wheels.
