Abstract: A load control device for a working tool of a construction vehicle in which a signal detected by a speed detector or a traction force detector is fed back to produce a deviation signal between said signal and a desired signal. A memory unit has stored a desired value of speed or traction force for each acceleration and outputs the desired signal corresponding to an acceleration signal from an acceleration detector. The working tool is moved up or down according to the deviation signal and, through the feedback mechanism, the load applied to the working tool is automatically controlled so as to enable the construction vehicle to work at maximum work efficiency without operator's efforts.

Abstract: The control device for an earthwork machine according to the invention is designed for reducing the manufacturing cost of the earthwork machine by eliminating some of the calculating circuitry and the control circuitry. According to the control device, one of the cylinders necessary for carrying out straight excavation is directly manually controlled without using calculating circuitry, and the operations of the cylinders are respectively detected by detecting circuitry. The other two cylinders are also controlled by the arithmetic unit provided in the control device for performing calculation necessary to move the sharp edge of the bucket along a straight line of predetermined inclination in accordance with detected pivoted angles of the boom, arm and bucket.

Abstract: An automatic control device for an earth working equipment is directed to remove influence of acceleration on an inclinometer mounted on a vehicle body and thereby to effect an accurate blade control. An acceleration compensation arithmatic circuit receives outputs of a pair of inclinometer and removes an acceleration component by performing integration twice. This circuit is also designed to remove an integration error. Further, according to the invention, a Doppler radar system and an engine speed/throttle opening system are employed for detection of overload applied to the blade so that one of the detection systems which is most suitable for an actual work can be selected. Furthermore, the device includes both blade height controllers and tilt controllers and performs the two control operations most effectively.

Abstract: An unmanned conveying control system capable of conveying a load between a base position such as a gateway of a warehouse or a predetermined position in a manufacture line in a factory and a storage place in the warehouse or factory as well as loading and unloading of the load in such base position and storage place completely automatically and without an operator. A load conveying way is defined by leader cables along which an unmanned travelling vehicle is guided. Leader cables are provided along load storage lines (lanes) in the warehouse or factory and a central control unit gives out load storage and load delivery instructions and applies a guide signal only to a lane in which the vehicle should be guided. The vehicle detects the state of the load placed in front of the vehicle and transfers the load from the vehicle to a required layer of a stacked load when the vehicle has received the load storage instruction, or from a required layer to the vehicle when it has received the load delivery instruction.

Abstract: In a civil machine comprising a working tool provided on a vehicle with a travelling mechanism and a drive therefor, an automatic control system comprises a stroke detector for detecting the amount of stroke of a lifting cylinder operating to move the working tool up and down, an inclination angle detector for detecting the inclination angle of the vehicle, an arithmetic unit for obtaining data representative of the height of the working tool from the detection signals of the two detectors, and a control for operating the lifting cylinder by using the data to control the position of the working tool with high accuracy.