Control arrangement for vehicle memory seat

Abstract

A control capable of moving a powered seat bidirectionally along at least one travel path includes memory having a segment for storing the present position of the seat and segment(s) for storing one or more 'memory' or 'recall' positions to which the seat may be automatically directed via appropriate switch actuation and associated logic. The memory is of limited capacity, with a memory segment of less than 2N capacity being utilized for storing the present position data associated with an axis or path of travel. Similar limitations in capacity preferably apply to the memory segments associated with the storage of respective 'recall' positions. The value N is equal to the number of digital signals produced by a displacement sensor during the driven displacement of the seat through the full extent of its travel path in one direction. Compensating means respond to the count in the present position memory reaching a limit for appropriately incrementing or decrementing the count(s) representative of the respective 'recall' positions for maintaining an accurate relation between the stored count data. This arrangement permits the counts in the several memory segments to be initially set to a mid-position, regardless of the actual positioning of the seat. The compensation may be done in hardware with an overflow register or in software by real-time adjustment of the count.