The early AGV can just move unidirectionally on automatic mode, so the environment is limited. For meeting the requirement of industrial production, due to the progress of driving units, in recently years, there have been the AGV products can move forward, backward, or with lateral movement and rotation when on auto-driving mode.
Brief introduction of AGV moving
1, Two-wheel differential speed driving unit. For this unit, two driving wheels are installed symmetrically, another supporting wheel is installed at the isosceles triangle vertex. The vehicle drives the two differential driving wheel, so steering wheel are not installed. This vehicle has simple structure, reliable working ability, and in low cost, it can move back and forth, even make the vertical turning on auto-run mode. Comparing with the four-wheel driving vehicle with steering wheel, this vehicle saves the cost of steering wheel and two driving motor, it can even be made smaller thanks to the saved space. This vehicle has been widely used in recently years. For better lateral movement stability, the four-wheel unit with two differential speed driving can be improved like this: add two more supporting wheels up to four, and install at the four corners of the vehicle chassis.
2, Three-wheel driving unit. The front wheel is the steering wheel, and the two supporting back wheels are the powerless, those wheels are installed as a triangle. This vehicle has simple structure, reliable working ability and in low cost. When on manual mode, this vehicle can move back and forth, and turn. When on auto mode, it can just move unidirectionally, the trail of back-middle wheel is out of guidance tape, it looks like dragging trail when on turn.
3, Four-wheel driving unit with steering wheels. The four-wheel driving unit with steering wheels is developed from the three-wheel driving unit. Actually it’s a combination of two three-wheel vehicles. The front or back wheels are for driving and steering. When on auto-mode, this AGV can move in any direction, the wheels can follow the guidance tape, it has better flexibility than the triangle wheel vehicle, so it’s good for the operation on narrow passageway.
4, Other driving units. New driving units have been developed by foreign companies in recent years, and the most representative one is the Mecanum Company of Sweden. This driving unit has new and compact design, the four driving wheels are installed as hinge joints at the four corners of chassis. Complish automatic driving by controlling the turning of the four wheels and using the velocity vector composition principle. Later Mitsui Company of Japan and Mecanum Company cooperated together, improved and put out the better- performance Mitsui-Mecanum Wheel System, which can drive in any direction.
