Abstract: An automatic control system operates to control the spout position on a forage harvester as a function of the position of a crop-receiving wagon and as a function of the relative spout-wagon position. The system includes wagon and spout angle sensors and a variable gain error amplifier for generating an error signal representing the difference therebetween. The gain of the error amplifier is modified according to changes in the wagon position to provide a wagon position dependent amount of free play in the spout-wagon relative position.

Abstract: A tractor-planter guidance aid system including a TV camera mounted on a servo motor at an end of the planter to view a mark in the terrain created by a marker mounted on the other end of the planter. Angle sensors send signals to a control circuit, these signals representing the angle between the tractor and the planter and between the camera and the planter. The control circuit cooperates with the servo motor to maintain the camera in parallel alignment with the tractor. A TV monitor displays the image detected by the camera to the operator of the tractor.

Abstract: A rugged and inexpensive sensor is disclosed for monitoring fuel injection characteristics such as injection pulse timing and width. A clamp is provided with hand grips and expandable jaws for quickly coupling to a fuel injection line. The jaws are biased into engagement with the line but are easily opened for releasing the clamp by urging the hand grips together. A transducer mounted on the clamp senses mechanical vibration caused by pressure pulsations in the line. The transducer is connected to circuitry for providing an output when the signal level from the transducer exceeds a threshold level. The sensor is self-compensating with the threshold level determined automatically from the maximum signal from the transducer. Therefore, different injection lines can be monitored with no manual adjustment of the clamp or circuitry even though the output of the transducer may vary from line to line.