POSITION CALCULATING SYSTEM AND HAULAGE VEHICLE

• US 20160069675A1
• Filed: 08/27/2015
• Published: 03/10/2016
• Est. Priority Date: 09/04/2014
• Status: Active Grant

• Current Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi Construction Machinery Company Limited (Hitachi, Ltd.)
• Inventors: BANDO, Mikio, ISHIMOTO, Hidefumi, SAITO, Shinjiro
• Granted Patent: US 9,709,391 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01B 21/00 Measuring arrangements or details thereof, where the measuring technique is not covered by the other groups of this subclass, unspecified or not relevant
• CPC Class Codes: G01C 21/16 by integrating acceleration or speed, i.e. inertial navigation
• CPC Class Codes: G01P 3/00 Measuring linear or angular speed; Measuring differences of linear or angular speeds G01P5/00 - G01P11/00 take precedence; direction and speed indication G01P13/045; counting mechanisms G06M

Abstract

Disclosed is a position calculating system for a haulage vehicle including wheels and a body frame mounted on the wheels. The system includes an attitude detection sensor fixed on the body frame, a wheel rotational speed sensor, a loading status information acquiring unit, a correction amount setting unit, a velocity vector calculating unit, and a position calculating unit. The loading status information acquiring unit acquires loading status information indicating whether the body frame is in a loaded state or in an unloaded state . The correction amount setting unit calculates, based on the attitude information, a correction amount required for bringing detection axes in the loaded state into coincidence with corresponding detection axes in the unloaded state. The velocity vector calculating unit calculates the velocity vector of the haulage vehicle. The position calpulating unit calculates a position of the haulage vehicle by using the velocity vector.

Claims

1. A position calculating system for being mounted on a haulage vehicle including wheels and a body frame which is mounted on the wheels via suspensions and carries a body mounted thereon, comprising:

an attitude detection sensor configured to output attitude information indicating an attitude of the body frame relative to the wheels,

a wheel rotational speed sensor that outputs a rotational speed of one of the wheels,

a loading status information acquiring unit configured to acquire loading status information on the body frame, said information indicating whether the body frame is in a loaded state with a load carried thereon or in an unloaded state with the load not carried thereon,

a correction amount setting unit that calculates, based on the attitude information, a correction amount required for bringing detection axes, which are to be used upon outputting the attitude information in the loaded state, into coincidence with corresponding detection axes, which are to be used upon outputting the attitude information in the unloaded state, and that sets the correction amount as a correction amount for use in calculating a velocity vector of the haulage vehicle in the loaded state,

a velocity vector calculating unit that determines, based on the loading status information, whether the body frame is in the loaded state or the unloaded state and that, when the body frame has been determined to be in the loaded state, calculates the velocity vector of the haulage vehicle by using a wheel speed available from the rotational speed of the one wheel, a direction of motion of the haulage vehicle as determined from the attitude information, and the set correction amount, and

a position calculating unit that calculates a position of the haulage vehicle by using the velocity vector.

2. The position calculating system according to claim 1, wherein, when the vehicle is determined to be in the unloaded state based on the loading status information, the correction amount setting unit deletes the calculated correction amount and sets another correction amount expressed in terms of an identity matrix.

3. The position calculating system according to claim 1, further comprising a correction amount storage unit that stores the correction amount calculated beforehand,

wherein, when the body frame is determined to be in the loaded state based on the loading status information, the correction amount setting unit, instead of the calculation of the correction amount, reads the correction amount from the correction amount storage unit and sets the same.

4. The position calculating system according to claim 1, further comprising a map information storage unit that stores map information indicating a travel route which connects a loading point where the load is loaded and an dumping point where the load is dumped,

wherein, based on whether the loading point or the dumping point has been reached based on the position of the haulage vehicle as calculated by the position calculating unit and the map information, the loading status information acquiring unit determines whether the body frame is in the loaded state or in the unloaded state, and generates the loading status information that indicates a result of the determination.

5. The position calculating system according to claim 1, wherein the loading status information acquiring unit compares an output from a suspension pressure sensor, which detects a pressure of one of the suspensions provided in the haulage vehicle, with a threshold level of suspension pressure for use in distinguishing the unloaded state or the loaded state, and based on a result of the comparison, generates the loading status information.

6. A haulage vehicle including wheels and a body frame which is mounted on the wheels via suspensions and carries a body mounted thereon, comprising:

an attitude detection sensor configured to output attitude information indicating an attitude of the body frame relative to the wheels,

a wheel rotational speed sensor that outputs a rotational speed of one of the wheels,

a loading status information acquiring unit configured to acquire loading status information on the body frame , said information indicating whether the body frame is in a loaded state with a load carried thereon or in an unloaded state with the load not carried thereon,

a correction amount setting unit that calculates, based on the attitude information, a correction amount required for bringing detection axes, which are to be used upon outputting the attitude information in the loaded state, into coincidence with corresponding detection axes, which are to be used upon outputting the attitude information in the unloaded state, and that sets the correction amount as a correction amount for use in calculating a velocity vector of the haulage vehicle in the loaded state,

a velocity vector calculating unit that determines, based on the loading status information, whether the body frame is in the loaded state or the unloaded state and that, when the body frame has been determined to be in the loaded state, calculates the velocity vector of the haulage vehicle by using a wheel speed available from the rotational speed of the one wheel, a direction of motion of the haulage vehicle as determined from the attitude information, and the set correction amount, and

a position calculating unit that calculates a position of the haulage vehicle by using the velocity vector.