Motor Controller Module Design
Stilwell Baker was engaged by a U.S. manufacturer to design and manufacture a complex controller module to be used 24/7 in thousands of commercial locations throughout the United States. The customer had never developed a product containing electronic components and their engineering staff had limited knowledge of electronic engineering, or manufacturing circuit board assemblies.
Each controller module is a CAN-bus connected embedded controller used to drive motors on multiple channels, and monitor switch positions and tamper sensors as directed by a kiosk computer. The controller module monitors inputs and reports to the kiosk computer at any change in status. The controller module contains a microcontroller with embedded firmware and accelerometer to detect tamper events and control the functions of the controller module. The controller module has inputs from and outputs to the module hardware, and the CAN-bus provides a communication path to the kiosk computer and other module controllers on the bus. The controller module is an 8 layer, single-sided SMT conformal coated circuit board, and each system contains 12 boards.
In addition to a short development cycle, and a requirement for robust tamper resistance, the preliminary specification stated that the controller module and kiosk computer maintain continuous operation in an uncontrolled outdoor environment for 10 years.
Working in collaboration with the customer, Stilwell Baker generated the detailed specifications for the module controller, and engineered the detailed design to UL, EMC, ESD, Environmental, and MTBF requirements. The engineering team conducted a system FMEA, system level MTBF analysis, wrote firmware, produced prototypes, and managed integration as well as environmental and life cycle testing for the finished product. The new product is on track for a national rollout and Stilwell Baker continues to provide engineering and manufacturing support.