The invention relates to a method and an apparatus for angle measurement or for the determination of an angle of position for an object. The method comprises the use of a beacon having a known position and rotating around its axis, which emits light or reflects light focused thereon. The light emitting from the beacon being determined either previously or for the start of each measurement for a given reference bearing. In the method, the light emitted from the beacon is picked up by a receiver present in an object to be measured, which is provided with elements for determining, by means of the light received from the beacon, the rotational speed of the beacon and further an angular position for the object with respect to said reference bearing. The method is further capable of measuring a distance by using a conventional know base with a receiver at each end, whereby the distance between an object to be measured and the beacon can be determined by working out the triangle or by measuring the peripheral speed between the receivers and by making use of the knowledge about the angular speed of the beacon.

The present invention is an apparatus and method for accurately determining the position of a tool, for example an earthmoving bucket, mounted at the end of an arm which has a plurality of pivot points and is pivotally attached to the base of a machine, for example a piece of construction equipment like the platform of an excavator or other earthmoving machine. The present apparatus includes a plurality of reflectors mounted on the machine for indicating movement of the arm and the tool. Each reflector is operatively adapted for reflecting light back toward a light source. A light transceiver is mounted on the machine in a known relationship to the reflectors. The light transceiver is operatively adapted for transmitting a beam of light to illuminate each of the reflectors, thereby generating reflective light. The light transceiver detects the reflective light and the angular orientation of the reflective light it detects. The light transceiver is also adapted to generate an output signal in response to the reflective light and the angular orientation it detects. A computer computes the position of the tool using the output signals of the light transceiver generated in response to the reflected light and the angular orientation of the reflected light. The present position determining system is relatively simple in construction, inexpensive and readily installed, including on construction equipment like various types of conventional earthmoving machines.

System for positioning a vehicle within a predetermined area, which system is provided with a laser transmitter/receiver and three or more laser reflectors which are located outside and/or inside the predetermined area, the position of the laser transmitter/receiver with respect to the laser reflectors being determined continuously with the aid of a method known per se. The position of a reference point on the vehicle with respect to the laser reflectors is determined continuously with the aid of the laser transmitter/receiver . The vehicle is provided with movable parts with which predetermined work can be carried out and is provided with sensors with which the position of a number of movable parts of the vehicle is measured continuously, which parts are determining for the relative position, with respect to the reference point, of the location where the said work is carried out. Furthermore, a processor is present, which is designed and/or programmed in such a way that said processor processes the output signals from the said sensors and from the laser transmitter/receiver and on the basis of said signals determines the position of the location where the work is being carried out, with respect to the laser reflectors.