Patent ID: 7831362
Filing Date: 2010-11-09
Classification: E02F,G01S

Abstract:
1. A position measuring system for a hydraulic excavator comprising a lower travel structure, an upper swing body swingably mounted to said lower travel structure and a front operating mechanism mounted to said upper swing body, the position measuring system comprising: a first means for measuring three-dimensional positions disposed in said upper swing body and measuring positions of said upper swing body in a three-dimensional space when said first three-dimensional position measuring means is in a first state of measurement accuracy; a second means for measuring three-dimensional positions disposed in said upper swing body and measuring positions of said upper swing body in a three-dimensional space independently of said first means when said second three-dimensional position measuring means is in a first state of measurement accuracy; means for computing a position of a monitoring point in the three-dimensional space based on values measured by said first and second position measuring means; means for measuring a yaw angle of said hydraulic excavator; and display means, wherein said position computing means computes the position of the monitoring point based on a coordinate system of said front operating mechanism when both said first and second three-dimensional position measuring means change from said first state of measurement accuracy, and wherein, when the measurement accuracy of both said first and second three-dimensional position measuring means changes from said first state, movement of said upper swing body, which is movement of a front mechanism including swing movement is enabled, and said position computing means displays at said display means that travel of said lower travel structure is prohibited.