Abstract: A fixture for interacting with an exhaust system having exhaust pipes and mufflers and an image of the exhaust system, the image having location indicia locating the fixture on the image, displacement data associated with the location indicia indicates an alignment point in space above the image, the fixture comprising at least two stands adapted to lie in a selected positions relative to the image, an alignment mark on the stands, the alignment mark being adapted to align the stands with the location indicia on the image, and at least two modules, a plurality of holders configured differently from one another to be attached to a module, each holder defining a coordinate point that moves relative to the stand and image in response to movement of the module relative to the stand, the plurality of holders including at least one pipe holder configured to receive the exhaust pipe therein to position a central axis of the exhaust pipe at the coordinate point and a muffler holder configured to cooperate with anothe

Abstract: An electronic sensing and control circuit is provided which includes a sensing plate and means for charging the sensing plate to a value dependent upon the capacitance existing between the sensing plate and a remote object. The capacitance between the sensing plate and the object varies with the distance of the object relative to the sensing plate. The sensing plate is periodically discharged and charged producing a useful current proportional to the capacitance and varying with the distance between the sensing plate and the object. Two sensing plates are used to provide first and second signals. The first and second signals are subtracted to derive a lateral displacement signal and added to derive a distance signal. The lateral displacement signal and the distance signal can be used to control the forward, reverse and turning motion of a motorized wheelchair.