Patent Application
20090219199
This disclosure relates generally to a positioning system and, more particularly, to a positioning system for projecting a site model.
The construction industry often employs computer systems for digitally mapping work sites, particularly for operations such as earth-moving. To facilitate digital mapping, construction personnel typically provide earth-moving machines with global positioning systems (GPS). As an alternative to employing standard surveying teams, construction personnel use a machine with GPS to produce an initial survey of a work site. The machine with GPS moves back and forth across a worksite, collecting three-dimensional GPS coordinates and providing the data to a computer. The computer, which may be located on board of the machine or located remotely, inputs the data into a software application or algorithm to create a three-dimensional model of the actual contours of the worksite. This model provides the initial survey of the work site.
Construction personnel also provide input to the computer corresponding to a final desired design plan for the work site. The computer compares the actual terrain contours and the design plan contours to verify the total amount of earth-moving that construction personnel must perform. When operations such as earth-moving begin, a number of machines with GPS may transmit updated GPS information to the computer, which uses the new coordinates to constantly update the actual contours of the terrain map. The computer periodically compares the actual contours to the design plan for the work site. The computer typically provides the terrain map data to construction personnel through a conventional computer monitor display. The computer displays highlighted areas of the work site that need work such as cutting or filling. Construction personnel use the display to verify the progress of construction work such as, for example, earth-moving. Since construction personnel have substantially real time comparison of actual contours to design plans, they can determine if machines are working in the correct locations.
One shortcoming of the above-described scheme is the difficulty operators have when looking back and forth between the display monitor and the actual worksite visible through the windows of his machine. The display may show a large amount of precise plan lines, which may be difficult for an operator to mentally transpose between the display and the physical changes he is making to the worksite. Additionally, continuously glancing back and forth between the display and the actual worksite for long periods of time may become mentally exhausting and may cause the operator to work less efficiently.
U.S. Pat. No. 5,751,576 (the '576 patent), issued to Monson, discloses an animated map display method for an agricultural product application. The '576 patent describes an animated map display transposing information related to geological or environmental features, physical structures, sensor signals, status information, and other data for distributing an agricultural product onto a field. The data is displayed as a two- or three-dimensional representation that is projected using a heads-up display (HUD) overlaid onto the real-world terrain and environment visible to the operator through the windshield (or windows) of a machine. The animated map display may present information relating to a particular map set as a three-dimensional image corresponding spatially to real-world terrain or environment, as well as including alphanumeric, pictorial, symbolic, color, or textural indicia relating to navigational, sensor, or other data inputs. The machine carries GPS to provide a coordinate location, and conventional computer processes are used to generate the three-dimensional images.
Although the method of the '576 patent may provide a method for displaying agricultural information for two-dimensional operations such as agricultural product placement, it may not provide a method for making calculations for three-dimensional operations and displaying the output from those calculations. The method of the '576 patent may not be configured to display three-dimensional design plans associated with construction work.
The present disclosure is directed to overcoming one or more of the shortcomings set forth above.
In accordance with one aspect, the present disclosure is directed toward a positioning system. The positioning system includes a database for storing a site model. The site model includes data indicative of a desired geography of a site environment and an actual geography of the site environment. The positioning system also includes a first receiver for generating digital signals representing a real time position in three-dimensional space of at least a portion of a machine as the machine traverses the site environment. The positioning system further includes a processor for receiving the signals and updating the site model to determine a difference between the data indicative of the desired geography and the data indicative of the actual geography. The positioning system also includes a display for projecting the site model onto at least one surface of an operator station of the machine so that an operator may simultaneously view the site model and the site environment.
According to another aspect, the present disclosure is directed toward a method for providing positioning data to an operator. The method includes storing data indicative of a desired geography of a site environment. The method also includes storing data indicative of an actual geography of the site environment. The method further includes receiving a real time position in three-dimensional space of at least a portion of a machine as the machine traverses the site environment. The method additionally includes updating the data indicative of the actual geography of the site based on the real time position. The method also includes determining a difference between the data indicative of the desired geography and the data indicative of the actual geography in real time. The method further includes updating and storing the difference. The method additionally includes projecting data onto at least one surface of an operator station so that the data indicative of the desired geography, the data indicative of the actual geography, and the difference may be viewed simultaneously with the site environment by an operator.
Referring to
Base reference module 40 may include a stationary GPS receiver 41 for the receipt and processing of GPS signals. Base reference receiver 41 may be a high accuracy kinematic GPS receiver. GPS receiver 41 may include a local reference antenna (not shown) and a satellite antenna (not shown). The satellite antenna may receive signals from global positioning satellites 14 (shown in
Position module 50 may include a kinematic GPS receiver 51, similar to GPS receiver 41. Module 50 may also include a matching computer 52 for receiving input from receiver 51 and kinematic GPS software 54 stored permanently or temporarily on computer 52. Module 50 may further include a standard computer monitor screen 56 and a matching transceiver-type digital radio 58 or other suitable communications device, which receives signals from radio 48 in base reference module 40. It is contemplated that position module 50 may provide updated GPS data relating to the three-dimensional location of machine 10.
Update module 60 may include an additional computer 62 for receiving input from position module 50 and one or more digitized site models 64, which may be digitally stored or loaded into the memory of computer 62. Module 60 may also include a dynamic database 66, also stored or loaded into the memory of computer 62. The data associated with model 64 and database 66 may describe various states of work site 12, in three dimensions. Model 64 may include a three-dimensional model of work site 12 as surveyed, as well as the desired three-dimensional plan of work site 12 during various phases of construction or other activity. Model 64 may also include a three-dimensional model of a final design plan for work site 12. Model 64 may further include updated data from module 50 for constructing a three-dimensional model (updated in real time) reflecting physical changes that machine 10 may make to work site 12. Therefore, at any given time, model 64 may include a current three-dimensional plan of the site. Computer 62 may contain algorithms that compare the actual state of work site 12 to the desired end state of work site 12 to calculate amounts and locations of work that still must be completed (e.g., cut volumes and fill volumes). Module 60 may further include a display 65, which may be connected to computer 62. Display 65 may be a heads-up display, as further described below. It is contemplated that module 60 may maintain an updated three-dimensional model of work site 12 to be used by an operator of machine 10 in completing operations such as, for example, construction work.
In an exemplary embodiment, some or all portions of update module 60 may be stationed remotely from machine 10. For example, computer 62, site model(s) 64, and dynamic database 66 may be connected by radio data link to position module 50 and display 65. Position and site update information may then be broadcast to and from machine 10 for display and/or use by operators or supervisors both on and off the machine. It is contemplated that operators may be located in an operator station 16 of machine 10.
In an exemplary embodiment, base reference module 40 may be fixed at a point of known three-dimensional coordinates relative to work site 12. Through GPS receiver 41, base reference module 40 may receive position information from a GPS satellite constellation, using the reference GPS software 44 to derive an instantaneous error quantity or correction factor. This correction factor is broadcast from module 40 to position module 50 on machine 10 via radio link 48,58. Alternatively, raw position data can be transmitted from base reference module 40 to position module 50 via radio link 48,58, and processed by computer 52. GPS receiver 41 may be positioned in any suitable manner known in the art such as, for example, on a tripod as illustrated in
In an exemplary embodiment, GPS receiver 51 may receive position information from the satellite constellation. Kinematic GPS software 54 may combine the signal from GPS receiver 51 and the correction factor from base reference module 40 to determine the position of GPS receiver 51 and machine 10 relative to base reference module 40 and work site 12 within a few centimeters (about an inch). It is contemplated that this position information may be three-dimensional (e.g., latitude, longitude and elevation) and may be available on a point-by-point basis according to a sampling rate of the GPS system.
Because the sampling rate of position module 50 results in a time/distance delay between position coordinate points as the machine moves over the site, dynamic database 66 may use a differencing algorithm to determine and update in real time the path of machine 10. Referring to update module 60, once the digitized plans or models of work site 12 have been loaded into computer 62, dynamic database 66 may generate signals representative of the difference between actual and desired site terrain to display this difference graphically on display 65. For example, profile and/or plan views of the actual and desired site models may be combined on display 65 and the elevation difference between their surfaces may be indicated.
Referring to
As shown in the exemplary embodiments of
In an exemplary embodiment, CRT projector 67 may include a focusing coil 71, which may be located near cathode 68. Focusing coil 71 may focus ray 74 within bulb 69. CRT projector 67 may also include deflecting plates 72. Deflecting plates 72 may direct ray 74 to a given location on face 70. Depending on the location on face 70 at which ray 74 is directed, light ray 76 may be directed out of CRT projector 67 in a certain direction. The voltage of cathode 68 may also be varied to change the intensity of ray 74. Computer 62 may include algorithms for controlling the components of CRT projector 67 to produce light rays 76 of a given direction and intensity.
Display 65 may be a refractive heads-up display, as shown in
CRT projector 67 may project the data, described above, associated with model 64 and database 66 onto windshields 18. CRT projector 67 may project any desired aspect of model 64. In an exemplary embodiment, CRT projector 67 may project the desired end state of work site 12, the actual state of work site 12 (for verification purposes by the operator), or the amount and location of work to be done (based on the calculations comparing the difference between the actual state and end state). It is contemplated that these aspects of model 64 may be color-coded when projected, so that operators may easily distinguish the desired end state, the actual state, and work remaining to be completed. In an exemplary embodiment, aspects of model 64 may be projected in different colors such as, for example, red, green, and blue, by light ray 76 and combined light 78 as described above. Based on the GPS processing defined above, the images may align with the actual terrain visible to the operator outside of operator station 16. Since windshields 18 may be semi-transparent, the operator may simultaneously view a three-dimensional model of a design plan for work site 12 projected onto windshields 18 and the actual terrain visible beyond windshields 18, where the projected terrain appears to overlay the actual terrain in the perspective of the operator.
In a second exemplary embodiment, display 65 may be a reflective heads-up display, as shown in
The exemplary disclosed positioning system and associated display may help to provide a method for calculating and displaying a site model to an operator. The disclosed positioning system and display may project the site model onto windshields of an operator station so that operators may compare the projected model with the actual conditions of a work site, allowing them to work more efficiently.
Machine-mounted GPS receiver 51 may receive position signals from satellites 14 and an error correction signal from GPS receiver 41 via radios 48,58 as shown in
The coordinates of GPS receiver 41 may be determined in any known fashion, such as GPS positioning or conventional surveying. Work site 12 may be previously surveyed to provide a detailed topographic blueprint (not shown) showing the architect's finished site plan overlaid on the original site topography in plan view. The creation of geographic or topographic blueprints of sites such as landfills, mines, and work sites with optical surveying and other techniques is a well-known art. For example, reference points may be plotted on a grid over the site and may be connected or filled in to produce the site contours on the blueprint. The detail of the map may increase with the amount of reference points taken. The map may be associated with model 64 and stored within database 66.
Systems and software may be currently available to produce digitized, two- or three-dimensional maps of a geographic site. For example, the architect's blueprint may be converted into three-dimensional digitized models of the original site geography or topography. The site contours may be overlaid with a reference grid of uniform grid elements in known fashion. The digitized site plans may be superimposed, viewed in two- or three- dimensions from various angles (e.g., profile and plan), and/or color coded to designate areas in which the site may need to be machined (e.g., removing earth and/or adding earth). Software may also estimate the quantity of earth required to be machined or moved, make cost estimates, and identify various site features and obstacles above or below ground as is known in the art.
Computer 52 of position module 50 may provide computer 62 with updated GPS data. Computer 62 may utilize this data in processing algorithms to update data associated with model 64 stored within database 66. Database 66 may determine the difference between the actual and desired site geographies of model 64 and use the updated GPS data to update and display model 64 in real time with a degree of accuracy measured in centimeters.
Computer 62 may provide data to symbol generator 75, allowing symbol generator 75 to control cathode 68. Cathode 68 may produce ray 74 of electrons, which may be focused by focusing coil 71. Ray 74 may travel through bulb 69 and be directed by deflecting plates 72 to strike the phosphors located on glass face 70 at a certain location, producing light ray 76. Light ray 76 may be emitted from CRT projector 67 in a direction corresponding to the location on glass face 70. Computer 62 may execute algorithms for controlling the components of CRT projector 67 to produce light rays 76 of a given direction and intensity.
In the refractive heads-up display shown in
Three-dimensional positioning system 100 and associated display 65 may help to provide a method for calculating and displaying output describing three-dimensional model 64 to an operator. Display 65 may project output onto windshields 18 of operator station 16 so that operators may immediately compare the projected output with the actual condition of work site 12 without having to look away from windshields 18. The operators may alter their actions based on the comparison while still looking through windshields 18, thereby making the work more efficient.
It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed positioning system and display. Other embodiments will be apparent to those skilled in the art from consideration of the specification and practice of the disclosed method and apparatus. It is intended that the specification and examples be considered as exemplary only, with a true scope being indicated by the following claims.
