Magnet Navigation
The Magnet-Gyro guiding and navigation system, used by Amerden, has a special made magnet position sensor used to find small magnets installed in the floor, and Gyroscope technology to keep the AGV heading direction continuously under control. In addition, there are odometer wheel and steering angle feed back, the same as used on vehicles with Amerden inductive wire guidance system. The magnet sensors give info rmation about the AGV position deviations and updates the odometer distance counting as the magnets are passed.
All this combined makes a system that can guide vehicles with the help of small magnets installed along the guide path, in the floor. A pair of magnets for every five to ten meters of AGV guide path is normally required. The cost to install such guide path is a fraction of the cost of a guide wire installation. About four to eight times less compared with Amerden’s already inexpensive and easy to install wire guidance, and maybe ten to twenty times less expensive than some other older fashioned types of wire guiding systems for AGVs. Magnets can easily be installed in wood floors and other types of environment not well suited for guide wire installation.
Compared with laser guidance the onboard controls are simpler and the vehicle prices much lower. The cost to install magnets in the floor may be less than the installation of laser reflectors required. The software to program vehicles with Magnet-Gyro navigation is an extended version of Amerden P-turn ( Programmable turns) used to let wire guided vehicles move and turn off the guide wire. This proven software, with the ability to program the vehicle movements by teach in procedures, has been further developed for the Magnet-Gyro navigation system.
The Amerden free ranging Magnet-Gyro guidance system has high accuracy by use of high quality components. A low cost is achieved by using a combination of standard components together with our standard control board and standard software. The system is easy to install and program.
The disadvantage with the Magnet-Gyro guidance compared with wire guided systems is higher cost for the onboard navigation. It is five to ten percent increase in vehicle price, and maybe less guiding accuracy and some more programming on site at the system installation.
The magnets in the floor may collect small magnetic particles in the environment; this will however not cause any big problem under normal conditions.
The gyro sensor is a solid state, single axis, angular rate sensor. The gyro sensor gives direction of the vehicle and provides an output voltage proportional to the rate of turn at its sensitive axis. The gyro sensor uses the Coriolis Effect to detect angular rate.
The magnet sensor is micro computer based and is using hall elements to detect magnetic field from magnets. The magnet sensor detects small magnets installed in the floor with high accuracy. The magnet sensor gives X and Y coordinates of the AGV when updating on magnets.
The magnets are rare earth type and normally 10 mm in diameter and 15 mm long. They are installed in a drilled hole in the floor and covered with epoxy giving a smooth and flat floor surface. The distance between the magnets in the floor is depending on the type of vehicle and accuracy demands. Typical is to install a pair of magnets every five to ten meters, and after a programmed turn closer.
Magnet-Gyro guidance is mainly intended for tricycle AGVs. Please contact Amerden for other applications! The Magnet-Gyro guidance system may also be combined with wire guidance, for instance in narrow aisles for backup at manual operation.