PROBLEM TO BE SOLVED: To output a proper vehicle speed corresponding to a work state.SOLUTION: A vehicle speed detector includes: a reception part which receives satellite signals from a positioning satellite and is attached to a vehicle body having a work device a first vehicle speed calculation part which calculates a first vehicle speed of the vehicle body on the basis of the satellite signals received by the reception part a second vehicle speed calculation part which calculates a second vehicle speed based on a vehicle speed detection part by a rotation number of wheels attached to the vehicle a slip calculation part which calculates a slip ratio on the basis of the first vehicle speed and the second vehicle speed calculated in both vehicle speed calculation parts a main vehicle speed output determination part which determines output of either first vehicle speed or second vehicle speed on the basis of the slip ratio calculated in the slip calculation part and a vehicle speed output part which outputs the vehicle speed determined in the main vehicle speed output determination part.COPYRIGHT: (C)2014,JPO&INPIT【課題】作業状態に応じた適正な車速を出力することができるようにする。【解決手段】測位衛星からの衛星信号を受信し且つ作業装置を備えた車体に取り付けられる受信部と、受信部が受信した衛星信号に基づいて車体の第1車速を算出する第1車速算出部と、車体に設けられた車輪の回転数による車速検出部に基づく第2車速を算出する第2車速算出部と、両車速算出部で算出された第1車速と、第2車速とに基づいてスリップ率を算出するスリップ算出部と、スリップ算出部で算出されたスリップ率に基づいて第1車速と第2車速とのいずれかの出力を決定する主車速出力決定部と、主車速出力決定部で決定された車速を出力する車速出力部とを備えている。【選択図】図1
