Development of the 3-D Hall Sensor ASIC:
Marquardt's team, in close collaboration with the Fraunhofer Institute for Integrated Circuits, developed a new application-specific integrated circuit (ASIC) for a 3-D Hall sensor that measures the three vector components of a magnetic dipole field. The complete measurement system consists of a magnet attached to the drum in the washing machine and the 3-D Hall sensor ASIC connected to the appliance housing. The Hall sensor measures the direction and strength of the magnetic field, determining the relative movement of the magnet in three dimensions. This information is then communicated to the embedded microcontroller, which applies a proprietary algorithm to determine the drum's movement control mode.

To develop the algorithm, Marquardt's group turned to Maple™. Dr. Allmendinger found Maple to be an invaluable tool that allowed him to work on complex problems such as magnetic field modeling, estimating allowable tolerances for the magnet, and determining whether the tilt of the 3-D Hall Sensor module was within a very small tolerance of approximately two degrees. The resulting algorithm was then converted to C code to drive the controller.
Dr. Allmendinger first worked with Maple while a university student. He was impressed by Maple's ability to work with symbolic mathematics, its powerful graphical tools, its technical documentation interface, and its ability to export to other languages ​​(such as C, MATLAB®, and Java™). Dr. Allmendinger stated: “Maple proved very easy to work with, even with the complex mathematics involved. We found it quite simple to enter and modify equations, determine if they had a solution, then go back and make the necessary changes. I found Maple's user interface very easy and comfortable to use; in particular, the export capabilities and interoperability with other technical programs have improved significantly and are now invaluable for the rapid development of the solution.”

The new 3D positioning system in the Hall sensor offers several advantages. First, its assembly is simple since there is no mechanical connection between the magnet and the sensor. Because the measured values ​​of the three magnetic field components can be recorded simultaneously, the sensor system also offers the option of calculating speed. Overall, the design allows for more responsible management of natural resources. The use of mathematical modeling of the field eliminates the need for traditional 3D planning techniques and allows for the use of a smaller, more economical microcontroller.
Fewer resources are also used by creating a significantly smaller magnet.

Marquardt is currently exploring other applications for its 3D sensor with other well-known clients. These applications include general position sensing in production and automation technology, and multimedia interfaces in the automotive industry, such as the iDrive system in a BMW™ vehicle. The company is also studying further development of this innovative sensor concept, expanding its capability to determine not only the 3D distance of a Hall sensor from a magnet but also a 3D solid angle. This sensor concept will require measuring the magnetic field at two positions. This problem will require a six-dimensional system of equations, and Maplesoft will also be used in the development of this project.
Maplesoft is represented in Spain by Addlink Scientific Software.

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