An AGV controller for the Intelligent Transport Systems Laboratory.
Report 2003.TL.6782, Transport Technology, Logistic Engineering.
The motion control of a vehicle following some predescribed path involves
the control of its position and velocity at every instant of its travel.
In a simple Feedback Control technique for an Automated Guided Vehicle
(AGV), this translates to a precise measurement of its present position
and the desired position along the path at several instances of time. A
feedback comparison can then be made between these two positions for
generating an error signal, which can be used to correct the AGV motion.
Comparisons of both the lateral positioning and longitudinal positioning
or heading along the path are necessary for an effective control strategy.
With a small-generated error signal on the system, accurate and repeatable
system performance can be achieved.
The mini AGVs do not have a very fast dynamics. A simpler linear kinematic
model has been used to generate the actuator inputs (steering signal and
motor voltage) for position and speed control using feedback control
technique. The interaction between the controller and the real mini AGV is
studied with emulation tests. Emulation studies are meant to measure the
performance of the system before going into full-scale implementation,
which make it possible to make changes in the Mini AGV system or the
control system if necessary. Testing with emulation must reflect the real
situation as much as possible. The AGV position observation from camera
system is reported to the base station control system with some
inaccuracies. The emulation model includes this discrepancy for a valid
representation of the field mini AGV system.
The thesis describes the model on which the controller is based. The
optimal control parameters are chosen with matlab simulation and validated
in an emulation model. The performance of the controlled Mini AGV is
studied with an emulation model and conclusions are drawn.
Reports on Logistic Engineering (in Dutch)
, TU Delft