Position measuring system for working machine

• US 20050080559A1
• Filed: 09/29/2003
• Published: 04/14/2005
• Est. Priority Date: 10/02/2002
• Status: Active Grant

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: Fujishima, Kazuo, Ishibashi, Hideto
• Granted Patent: US 7,831,362 B2
• Time in Patent Office: Days
• US Class Current: 701/213
• CPC Class Codes: E02F 9/2045 Guiding machines along a predetermined path for graders E02F3/841; machines for construction of roads E01C19/004
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G01S 19/47 the supplementary measurement being an inertial measurement, e.g. tightly coupled inertial
• CPC Class Codes: G01S 19/54 using carrier phase measurements; using long or short baseline interferometry

Abstract

The invention is intended to provide a position measuring system for a working machine, which can accurately measure the position of a monitoring point and can ensure high working efficiency even when measurement accuracy of a machine-equipped GPS has changed. A panel computer (45) computes the position of the monitoring point, which is set on an operating mechanism, in a three-dimensional space based on values measured by GPS receivers (43, 44) and angle sensors (21, 22, 23). When measurement accuracy of at least one of at least two GPS receivers lowers, the panel computer (45) corrects the computation for the position of the monitoring point based on a yaw angle measured by a gyroscope (25) for measuring the yaw angle of a machine body.

Claims

1. A position measuring system for a working machine comprising a machine body and an operating mechanism, the position measuring system comprising:

at least two three-dimensional position measuring means (43, 44) disposed in said machine body and measuring positions in a three-dimensional space;

position computing means (45) for computing a position of a monitoring point in the three-dimensional space based on values measured by said at least two position measuring means; and

yaw angle measuring means (25) for measuring a yaw angle of said working machine,

said position computing means (45) correcting the computation for the position of the monitoring point based on the yaw angle measured by said yaw angle measuring means (25) when measurement accuracy of at least one of said at least two three-dimensional position measuring means (43, 44) lowers.

2. A position measuring system for a working machine according to claim 1, further comprising:

inclination amount measuring means (24) for measuring an inclination amount of said working machine,

wherein said position computing means (45) corrects the computation for the position of the monitoring point based on the yaw angle (25) measured by said yaw angle measuring means and the inclination amount measured by said inclination amount measuring means (24) when measurement accuracy of at least one of said at least two three-dimensional position measuring means lowers.

3. A position measuring system for a working machine according to claim 1,

wherein, when the correction is executed, said position computing means (45) informs an operator that the correction is being executed.

4. A position measuring system for a working machine according to claim 1,

wherein, when the measurement accuracy of all of said at least two three-dimensional position measuring means (43, 44) lowers, said position computing means (45) informs an operator that travel of said working machine is prohibited.

5. A position measuring system for a working machine according to claim 4,

wherein, when the measurement accuracy of at least one of said at least two three-dimensional position measuring means (43, 44) restores, said position computing means (45) informs an operator that travel of said working machine is enabled.

6. A position measuring system for a working machine according to claim 3, further comprising:

first display means (46) for displaying the position of the monitoring point in accordance with a computation result of said position computing means (45),

wherein notices to be informed to the operator are displayed on said first display means.

7. A position measuring system for a working machine according to claim 3, further comprising:

data output means (47) for outputting position data of the monitoring point obtained as the computation result of said position computing means (45);

data input means (56) disposed in a position different from said working machine and receiving the position data outputted from said data output means; and

second display means (59) for displaying the position of the monitoring point in accordance with the position data received by said data input means,

wherein notices to be informed to the operator are displayed on said second display means.

8. A position measuring system for a working machine according to claim 1,

wherein said operating mechanism (4) comprises a plurality of rotatable members (5, 6, 7),

the monitoring point is set on said operating mechanism,

said position measuring system further comprises angle measuring means (21, 22, 23) for detecting respective angles between adjacent two of said plurality of members of said operating mechanism, and

said position computing means (46) computes the position of the monitoring point in the three-dimensional space based on values measured by said at least two position measuring means (43, 44) and said angle measuring means (21, 22, 23).