Apparatus and method for controlling a hydraulic excavator
US4829418A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1987 |
| Grant date | May 9, 1989 |
| Priority date | — |
| Expiry date | Apr 24, 2007 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02F9/264
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A control for an excavator controls the position of the bucket cutting edge to a desired depth accurately by a calibrating laser receiver mounted on the excavator stick member and passed through a stationary laser plane wherever the stick is moved into or out of a trench. Linear position encoders monitor the length that the actuating cylinders are extended and lookup tables convert the encoder outputs to angle representations for determining the positions of the laser receiver and the cutting edge. Other lookup tables are utilized to avoid time-consuming iterative calculation procedures to provide real-time digital process solutions of trigonometric functions. The apparatus includes a unique laser receiver comprising a plurality of linearly aligned photo receptors with associated circuitry for producing an output representative of the receptor illuminated or, if a group of receptors are illuminated, the centermost receptor illuminated.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.