Apparatus and method for asset tracking

• US 20090198371A1
• Filed: 01/26/2009
• Published: 08/06/2009
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: TotalTrax, Inc.
• Original Assignee: TotalTrax, Inc.
• Inventors: Emanuel, David C., Mahan, Larry G., Ungerbuehler, Richard H.
• Granted Patent: US 8,565,913 B2
• Time in Patent Office: Days
• US Class Current: 700/226
• CPC Class Codes: B66F 9/0755 Position control; Position detectors
• CPC Class Codes: G01S 5/16 using electromagnetic waves other than radio waves
• CPC Class Codes: G06Q 10/087 Inventory or stock management, e.g. order filling, procurement or balancing against orders

Abstract

An apparatus and method for tracking the location of one or more assets, comprising an integrated system that identifies an asset, determines the time the asset is acquired by a conveying vehicle, determines the position, elevation and orientation of the asset at the moment it is acquired, determines the time the asset is deposited by the conveying vehicle, and determines the position, elevation and orientation of the asset at the time the asset is deposited, each position, elevation and orientation being relative to a reference plane. Mobile subsystems, each on a conveying vehicle, identify the location and orientation of that conveying vehicle using an optical position sensor unit viewing an array of optical position markers, determine the identity of the asset from a label, confirm acquisition of the asset, determine the elevation of the asset relative to the reference plane and communicate the tracking information to a fixed-base subsystem.

Claims

1. An apparatus for tracking the location of one or more assets, comprising an integrated system that identifies an asset, determines a time the asset is acquired by a conveying vehicle, determines the position and orientation of the conveying vehicle, determines the position, elevation and orientation of the asset at the moment it is acquired, determines a time the asset is deposited by the conveying vehicle, determines the position and orientation of the conveying vehicle at the time the asset is deposited, and determines the position, elevation and orientation of the asset at the time the asset is deposited, each position, elevation and orientation being relative to a reference plane, the integrated system comprising:

a) a fixed-base subsystem comprising;

1) a host computer having a computational unit, a data storage unit, a wireless local area network interface, a communications network interface and an operator interface,

2) a base station wireless local area network communication unit, connected to the computer, for communicating with one or more mobile communication units;

b) one or more mobile subsystems, each mounted onboard a conveying vehicle, each comprising;

1) a mobile computer device having a computational unit, a data storage unit, a sensor network interface for communicating with a plurality of onboard devices, a wireless local area network interface, and an operator interface; and

2) a plurality of onboard devices comprising;

i) an optical position sensor unit to determine the location in two dimensions and the rotational orientation of the conveying vehicle in a coordinate system on the reference plane;

ii) a load identification sensor device for detecting and identifying a label having a machine readable symbol on an asset and decoding the machine readable symbol;

iii) a load detection device, indicating the presence or absence of an asset on a lifting mechanism of the conveying vehicle, and sensing the distance between the asset and the conveying vehicle;

iv) a lift height detection device for determining the elevation of the lifting mechanism on the conveying vehicle relative to the reference plane;

v) a wireless local area network communication unit for communicating with the base station communication unit; and

vi) a driver interface for displaying material move instructions to the driver, and receiving data from the driver, so that

the fixed-base subsystem communicates with the mobile subsystem on the conveying vehicle to track that conveying vehicle to an origin location of an asset, the asset is detected and identified by the mobile subsystem on the conveying vehicle, the asset is acquired by the conveying vehicle, the load detection device confirms the presence of the asset on the conveying vehicle and the asset'"'"'s onboard position relative to the vehicle, the lift height detection device determines the elevation of the asset relative to the reference plane at the origin location, the conveying vehicle is tracked to deliver the asset to a destination location, the optical position sensor unit determines the location and the rotational orientation of the conveying vehicle, the lift height detection device determines the elevation of the asset relative to the reference plane at the destination location and the mobile communication unit communicates to the fixed-base subsystem the identity of the asset, the time of acquisition and delivery, and the location, elevation and rotational orientation of the asset at the destination location.

2. The apparatus of claim 1 wherein the host computer of the fixed base subsystem operates under the control of instructions stored in the data storage unit to perform the functions of:

a) receiving data from the wireless local area network interface and computing each conveying vehicle'"'"'s instantaneous location and orientation based on data received;

b) storing and managing short term and long term records of conveying vehicle tracking data, including instantaneous location, directional heading, velocity, presence or absence of an asset load, identification of the asset, distance of the asset from the conveying vehicle and elevation of the lifting mechanism;

c) creating a graphical display on the operator interface device of the instantaneous location and load condition of each and every vehicle within the facility;

d) receiving commands from the operator interface; and

e) communicating data to and from external computer units, such as inventory control systems, warehouse management systems, safety systems, via a communications network.

3. The apparatus of claim 1 wherein the base station wireless local area network communication unit and the mobile local area network communication unit operate in accordance with IEEE standard 802.11b or 802.11g to receive data from each mobile wireless local area network communication unit of each mobile subsystem on each conveying vehicle and the base station wireless local area network communication unit.

4. The apparatus of claim 1 wherein the one or more mobile subsystems each further comprise a mobile onboard computer unit having a computational unit, a data storage unit, a local area network interface and a driver interface, the computer unit operating under control of instructions stored in the data storage unit to receive, analyze, and store data from the optical position sensor unit, the load identification device, the load detection device, the lift height detection device, to display data on the driver interface, to receive instructions from the driver interface and to communicate with the host computer of the fixed-base subsystem through the network interface and the wireless local area network communication unit.

5. The apparatus of claim 1 wherein the optical position sensor unit of the mobile subsystem on the conveying vehicle comprises an upward-facing optical image acquisition unit for viewing one or more of a plurality of unique position markers having identifying indicia and positional reference indicia thereupon, the markers being arranged at predetermined positional locations within a coordinate space so that at least one position marker is within view, the image acquisition unit acquires an image of one or more position markers and the optical position sensor unit analyzes the image to determine the location in two dimensions and the rotational orientation of the conveying vehicle relative to the coordinate system.

6. The apparatus of claim 1 wherein the load identification device for detecting and identifying an asset comprises an optical label reader sensor facing the lifting mechanism of the conveying vehicle that acquires an image of a label on the asset, decodes asset identification information of the bar code symbol, and determines the location and pixel size of the label within the image, thereby also determining the position of the asset relative to the conveying vehicle.

7. The apparatus of claim 1 wherein the load detection device providing the digital signal indicating the presence or absence an asset on a lifting mechanism further generates a signal indicating the distance between the asset and the conveying vehicle.

8. The apparatus of claim 1 wherein the lift height detection device comprises an optical sensor mounted on the conveying vehicle and an optical target mounted on the lifting mechanism to generate a signal corresponding to the elevation of the lifting mechanism above the reference plane.

9. A method of directing the transport of and tracking the location of one or more assets, comprising:

a) one or more mobile subsystems, each on a conveying vehicle, each identifying the location and orientation of that conveying vehicle using an optical position sensor unit,

b) the one or more mobile subsystems each communicating the location and orientation of the respective conveying vehicle to a fixed-base subsystem,

c) a host computer in the fixed-base subsystem selecting a conveying vehicle and communicating with the mobile subsystem on that conveying vehicle to direct and track that conveying vehicle to an origin location of an asset,

d) an asset identification device in the mobile subsystem on the conveying vehicle detecting and identifying a label on the asset,

e) a lifting mechanism on the conveying vehicle acquiring the asset, a load detection device confirming the presence of the asset on the lifting mechanism and determining the position of the asset relative to the conveying vehicle,

f) the host computer in the fixed-base subsystem directing that conveying vehicle to deliver the asset to a destination location and tracking that conveying vehicle,

g) upon deposition of the asset at a destination location, the lift height detection device determining the elevation of the asset relative to the reference plane at the destination location, the load detection device confirming the absence of the asset on the lifting mechanism,

h) the mobile communication unit on the conveying vehicle communicating asset data to the fixed-base subsystem, the asset data comprising the identity, location, elevation and rotational orientation of the asset at the destination, and

i) the host computer storing the asset data in the data storage unit for subsequent use.

10. A method of tracking the location of one or more assets, comprising:

a) one or more mobile subsystems, each on a conveying vehicle, each identifying the location and orientation of that conveying vehicle using an optical position sensor unit,

b) the one or more mobile subsystems each communicating the location and orientation of the respective conveying vehicle to a fixed-base subsystem,

c) upon receipt of an asset delivery request, a host computer in the fixed-base subsystem selecting a conveying vehicle and communicating with the mobile subsystem on that conveying vehicle to track that conveying vehicle to an origin location of an asset,

d) an asset identification device in the mobile subsystem on the conveying vehicle detecting and identifying a label on the asset,

e) a lifting mechanism on the conveying vehicle acquiring the asset, a load detection device confirming the presence of the asset on the lifting mechanism and determining the position of the asset relative to the conveying vehicle,

f) the host computer in the fixed-base subsystem tracking that conveying vehicle to a destination location,

g) upon deposition of the asset at a destination location, the lift height detection device determining the elevation of the asset relative to the reference plane at the destination location, the load detection device confirming the absence of the asset on the lifting mechanism,

h) the mobile communication unit on the conveying vehicle communicating asset data to the fixed-base subsystem, the asset data comprising the identity, location, elevation and rotational orientation of the asset at the destination, and

i) the host computer storing the asset data in the data storage unit for subsequent use.

11. The method of claim 10, wherein the asset delivery request originates from a driver input to the mobile subsystem on a conveying vehicle.

12. The method of claim 10, wherein the asset delivery request originates from the host computer.