This paper describes the design and field evaluation of a microcomputer-based ski binding controller built around the Hitachi HD 63P01M1 CMOS microcomputer. Included in the controller are signal conditioning electronics intended to interface with a six load component strain gage dynamometer that measures the loading between the boot and the ski. The controller processes digitized dynamometer signals in order to determine when the boot should be released from the ski. If release is warranted, then the controller generates a release command signal. The controller is powered by a rechargeable battery pack, with a single charge sufficient for an entire day of skiing. In order to conserve battery power, the dynamometer bridges are excited by pulses. The controller also features a first-in first-out buffer memory, which stores about 3.5 s of dynamometer data. The dynamometer data can then be transmitted to an auxilliary tape recorder if desired. The tape recorder is not carried on the ski, however. Packaged in a watertight aluminum housing, the controller is mounted on the ski behind the boot.
The new binding system has been field tested by two test subjects. The instrumentation system both controlled binding release and stored segments of boot loading data. The release control algorithm used in the tests compared measured axial and fore/aft bending moments to constant threshold values. Segments of loading data are presented for one test subject in two test runs distinguished by unstaged falls.