This disclosure relates generally to machines, and, more particularly, methods and apparatus to determine work paths for machines.
A machine for construction, agricultural, or domestic applications may be powered by an electric motor, an internal combustion engine, or a hybrid power plant including an electric motor and an internal combustion engine. For example, in agricultural uses an operator may control the machine to harvest crops and/or plant seed, or accomplish some other task in a work area.
An example method disclosed herein includes determining whether the auxiliary machine is to assist the host machine in a plurality of work cells in a work area; based on determining whether the auxiliary machine is to assist the host machine in one of the plurality of work cells, assigning an auxiliary power mode for the one of the plurality of work cells, the auxiliary power mode comprising one of a neutral mode or a power assist mode; and in power assist mode, controlling the auxiliary machine to provide auxiliary tractive power in one of the plurality of work cells, and in neutral mode, controlling the auxiliary machine to free wheel in another one of the plurality of work cells.
An example apparatus disclosed herein includes a power selector to determine whether the auxiliary machine is to assist the host machine in a plurality of work cells in a work area, and, based on whether the auxiliary machine is to assist the host machine in one of the plurality of work cells, to assign an auxiliary power mode for the one of the plurality of work cells, the auxiliary power mode comprising one of a neutral mode or a power assist mode; and a controller to control the auxiliary machine in power assist mode to provide auxiliary tractive power in one of the plurality of work cells and to control the auxiliary machine in neutral mode to free wheel in another one of the plurality of work cells.
An example machine readable storage medium is disclosed herein having machine readable instructions which when executed cause a machine to determine whether the auxiliary machine is to assist the host machine in a plurality of work cells in a work area; based on determining whether the auxiliary machine is to assist the host machine in one of the plurality of work cells, assign an auxiliary power mode for the one of the plurality of work cells, the auxiliary power mode comprising one of a neutral mode or a power assist mode; and in power assist mode, control the auxiliary machine to provide auxiliary tractive power in one of the plurality of work cells, and in neutral mode, control the auxiliary machine to free wheel in another one of the plurality of work cells.
Methods and apparatus for planning a path for a machine to traverse a work area are disclosed herein. Example methods disclosed herein for planning a path for a machine include dividing a work area into one or more work cell(s) and determining potential work paths between the one or more work cell(s). Example methods further include determining cost factors for the one or more work cells associated with operating the machine in several directions defined by the potential work paths through the one or more work cell(s). Example methods further include assigning a power mode for the one or more work cell(s) for one or more potential work path(s) based on the cost factors and estimating a cost for the one or more work path(s) for operating the machine based on the power mode associated with the one or more work cells. Example methods further include selecting a preferential work path based on the cost for the one or more work path(s).
In some examples, determining the cost factors include, but is not limited to, analyzing an estimated load of the machine and/or any units connected to the machine while traversing the corresponding work cell, estimated time for traversing the corresponding work cell, and/or estimated available power remaining in at least one of the machine and/or a second machine connected to the machine while traversing the corresponding work cell.
Assigning a power mode associated with operating the machine in several directions through the work cells may include assigning one or more of a neutral mode, a regenerative braking mode, a power assist mode, an essential assist mode, a charge stop mode, or a forbidden mode to be implemented in the corresponding work cell based on estimated traction or power for the machine to traverse the work cell or potential work path.
In some examples, estimating costs for each of the potential work paths includes calculating an estimated energy consumption and/or estimated energy generation for the machine and/or a second machine connected to the machine. The preferential work path may be the potential work path with a lowest estimated energy consumption or a highest estimated energy generation.
The example host machine 110 includes, among other components, a path planner 102, a controller 104, machine measurement device(s) 106, an internal combustion engine (ICE) 108 and wheels 112. The example host machine 110 may also include an optional user interface 114. In some examples, the wheels 112 may be replaced by or used in addition to other one or more ground engaging element(s) (e.g., one or more tracks). The host machine 110 may also include a generator (not shown) coupled to the ICE 108 for providing off-board electrical power (high and/or low voltage).
The example controller 104 may be used in conjunction with the path planner 102 to control a machine configuration (e.g., the machine configuration 100) associated with the system 200. The example controller 104 may provide steering and/or power controls to ground implements of the machine configuration to enable the machine configuration to traverse a path selected by the path planner 102.
The example machine measurement devices 106 may be located on the host machine 110 and/or the auxiliary machine 120. In some examples, the machine measurement devices 106 may be located on a server associated with the host machine 110 and/or the auxiliary machine 120. The machine measurement devices 106 may be one or more devices and/or types of devices including a location determination unit, such as a GPS receiver to determine a location of the host machine 110 and/or auxiliary machine 120. An example GPS receiver included in the machine measurement devices 106 may include a receiver with a differential correction device or another location-determining receiver. In some examples, geographic location data created by the path planner 102 or received from the GPS receiver and/or other measurement devices 106 may take the form of a map. The measurement devices 106 of
In the example of
The machine configuration 100 for using the example path planner 102 in accordance with the present disclosure may be used to traverse a work area in a path selected by the path planner 102. The host machine 110 may be used as agricultural equipment, construction equipment, turf care equipment, etc. The host machine 110 of
Accordingly, the path planner 102 may be used to determine and/or select a path for the machine configuration 100 to traverse a work area by providing the selected path to the user interface 114. In some examples, the path planner 102 may provide instructions to a controller 104 of the machine configuration 100 to autonomously control the machine configuration 100. The example controller 104 may use any appropriate techniques for autonomously or semi-autonomously controlling the machine configuration 100 through providing power to the wheels 112, 126 from the ICE 108, the ICE 128, and/or motor(s) 124 and steering any combination of the wheels 112, 126. The controller 104 may be located on the host machine 110, the auxiliary machine 120, and or at a separate location in communication with the host machine 110 and/or auxiliary machine 120. The example path planner 102 is used for planning a work path for the machine configuration 100. The example path planner 102 determines a number of costs (e.g., monetary, time, etc.) for potential work paths for the machine configuration 100 based on a number of cost factors (e.g., topography, soil conditions, estimated load, desired speed of operation, etc.). In some examples, the path planner 102 provides a selected work path and/or potential work paths to the user via the interface 114. Alternatively, the selected work path may be provided to the controller 104 for use or execution.
The example path planner 102 of
The example path generator 240 of
The machine monitor 242 of
The example work area definer 244 of
The example path definer 246 receives the definition of a work area from the work area definer 244. The work path definer 246 determines potential work paths for the machine configuration 100 to traverse and/or complete a task for the entire work area or a portion of the work area. Each potential work path defined by the path definer 246 determines one or more directions of travel for the machine configuration 100 to traverse work cells of the potential work path. In some examples, the desired portion of the work area may include the work area less any obstacle, obstruction, unsafe region, and/or excluded zone, which may be designated as forbidden by the path generator 240, as disclosed herein. Each proposed work path may include a series of generally parallel rows along selected and/or proposed directions. The path definer 246 may also take into account whether a crop, such as a row crop, is present in the work area. Although a user/operator may define the desired portion of the work area, the path planner 102, using the path definer 246 and/or cost analyzer 250, may cooperate with an obstruction avoidance system or a safety system to define or modify the desired portion of the work area.
The example cost analyzer 250 receives the definition of a potential work path from the work path definer 246 and machine status or characteristics from the machine monitor 242. The cost analyzer 250 determines a power mode via power mode selector 252 and estimates cost factors of each work cell via cost estimator 254, as disclosed herein, for each work cell of a potential path based on the direction of travel through the work cells. The power mode determines how the auxiliary machine 120 utilizes its power sources (e.g., the electric motor/generators 124, the ICE 128 and generator 129, etc.) to traverse a work cell. The power mode selector 252 may select an auxiliary power mode for the auxiliary machine 120 from one or more of a neutral mode, a regenerative braking mode, a power assist mode, an essential assist mode, a charge stop mode, and/or a forbidden mode, though other modes may be considered. In some examples, the cost analyzer 250 confirms that the machine 100 has adequate power to traverse the potential work path and may then alter the power mode selected by power mode selector 252 to ensure the host machine 110 with the assistance of the auxiliary machine 120 has enough power and/or traction to traverse the potential work path. The cost analyzer 250 estimates one or more costs for the machine configuration 100 to traverse each of the potential work paths defined by path definer 246. The one or more costs may include without limitation fuel, labor, machine wear, and agronomic impacts.
The cost analyzer 250 uses an example power mode selector 252 in order for the cost estimator 254 to estimate a total cost factor value for each work cell of the potential work path. The power mode selector 252 considers the analyzed cost factors and determines one or more potential power modes for an example electric drive (e.g., the motor(s) 124) of the auxiliary machine 120 to use in each work cell of the potential paths. Accordingly, the selected power mode determines how the auxiliary machine 120 is controlled. Based on the analyzed cost factors, the power mode selector 252 may choose from at least one of a neutral mode, regenerative braking mode, power assist mode, essential assist mode, charge stop mode, and/or a forbidden mode; each of these modes is described herein. Other modes may additionally and/or alternatively be used.
The power mode selector 252 may select a neutral mode for a work cell of a potential work path when the cost analyzer 250 determines that the geographic features of the work cell include a generally flat and/or slightly sloped surface. Further, the cost analyzer 250 may determine that the ICE 108 of the host machine 110 has suitable power (beyond traction and/or payload needs) to recharge an electric storage device (e.g., the battery 122), if needed at any time for the remainder of a potential work path. In neutral mode, the motor(s) 124 of the auxiliary machine 120 are “free-wheeling” as they are neither providing power nor braking. In some examples, neutral mode may also allow for the electric drive to engage, discharging available energy, if an opportunity to recharge the electric storage through regenerative braking opportunity, disclosed herein, lies ahead in work cells of the corresponding potential work path, thus potentially saving unnecessary fuel from being used by the ICE 108 and/or the ICE 128.
The power mode selector 252 may select a regenerative braking mode for a work cell of a potential work path when the cost analyzer 250 determines that the geographic features include a declining contour in the work cell. In the regenerative braking mode, the motor(s) 124 of the auxiliary machine 120 enter a braking mode effectively slowing the machine configuration 100 while also charging the battery 122. Therefore, the machine configuration 100 can safely descend a downhill grade and generate additional energy that can be used in upcoming work cells of the corresponding potential work path.
The power mode selector 252 may select a power assist mode for a work cell of a potential work path when the cost analyzer 250 determines that the geographic features include an inclining contour and/or unstable surface conditions (e.g., mud, vegetation, snow, etc.). In such examples, the power assist mode is selected if the ICE 108 of the host machine 110 is able to provide enough traction and payload power by itself, although, the machine configuration 100 would perform at a slower rate, thus affecting costs such as time and/or labor. In some examples, the inclining contour and/or unstable surface conditions are determined based on user input and/or sensors located throughout the work area or on the machine configuration 100. For example, sensors detecting moisture in the soil may be used to determine the surface conditions of the work cell. In some examples, weather services or forecasts may be used by the machine measurement devices 106 to determine surface conditions (e.g., recent precipitation would indicate muddy conditions; recent arid weather would indicate firm surface conditions, etc.).
Accordingly, in power assist mode, the auxiliary machine 120 assists the host machine 110 in traversing the cell by providing additional power for traction, implement operation, and/or payload operation via the motor(s) 124, provided that enough power remains in the battery 122 and/or fuel supply of the ICE 128 of the auxiliary machine 120 to traverse the corresponding potential work path.
The power mode selector 252 may select an essential assist mode for a work cell of a potential work path defined by path definer 246 when the cost analyzer 250 determines that the geographic features include an inclining contour and/or unstable or difficult surface conditions (e.g., mud, vegetation, snow, etc.) in the work cell and the ICE 108 of the host machine 110 cannot provide adequate power for traction, implement operation, and/or payload operation to traverse the work cell at a given speed, or any speed, without assistance. In other words, the host machine 110 would not be able to solely traverse the work path (e.g., work the implement to traverse the work path) without assistance from the auxiliary machine 120. Accordingly, in essential assist mode, the auxiliary machine 120 provides additional power for traction, implement operation, and/or payload operation to assist the host machine 110 via one or more of the motor(s) 124 to enable the machine configuration 100 to traverse the work cell and/or potential work path.
The power mode selector 252 may select a charge stop mode for a work cell of a potential work path defined by path definer 246 when the cost analyzer 250 determines that an upcoming work cell of the potential work path may require an essential assist but the auxiliary machine 120 may not have adequate energy stored in the battery 122 or fuel tank to traverse the work cell in power assist mode. Accordingly, in charge stop mode, the machine host machine 110 may charge the battery 122 using power from the ICE 108 and/or the ICE 128 and/or an external power source.
The power mode selector 252 may select a forbidden mode for a work cell of a potential work path defined by path definer 246 when the cost analyzer 250 determines that the machine configuration 100 traversing the work cell would violate an operating rule. As an example, the potential work path may require the machine configuration 100 to traverse the work cell in a direction where geographic features, such as a steep side slope, would cause a tipping hazard. In the provided example, the work cell cannot be traversed in the direction defined by the potential work path provided by path definer 246, and the corresponding potential work path may be altered through adjacent work cells of the forbidden cell (e.g., work cells that share a border with the forbidden cell) and further analyzed by the cost analyzer 250. In such examples, the cost analyzer 250 improves safety operations and assists in defining and/or determining limits of operability for the machine configuration 100.
Accordingly, the power mode selector 252 may select power modes based on simulations of operating the machine configuration 100 through each work cell in different directions defined by each corresponding potential work path. The simulations may include without limitation vehicle models, payload models, logistics models, topography models, soil models, tractive surface models, and/or vegetation models.
Within the described simulations, the example power mode selector 252, and subsequently, the cost analyzer 250 may determine which power modes are feasible, possible, and/or most optimal from a cost standpoint, as described herein.
The example cost estimator 254 of
The cost estimator 254 may analyze several different cost factors for each potential work path, including geographic features (e.g., elevation data, topographic data, surface conditions, etc.) associated with different cells in the work area and/or machine characteristics received from the machine monitor 242. For example, if the geographic features indicate that the work cell is generally flat or planar with optimal surface conditions, the cost factors associated with operation of the machine in that work cell may vary insignificantly. As another example, if the geographic features indicate that the work cell has a slope and/or unstable surface conditions (such as mud, snow, vegetation, etc.), the cost factors associated with operating the machine through that cell may vary significantly depending the direction of travel through that cell of the work area. In such examples, the cost estimator 254 may use a minimum stored energy reserve threshold for determining costs when the vehicle finishes traversing an essential traction assist cell for the expected or average case.
The status of the above machine characteristics received from the measurement devices 106 via the machine monitor 242 may affect the cost factors for the machine configuration 100 to traverse the work cell based on the directions defined by a potential work path. For example, the cost estimator 254 analyzes the load, available fuel, and/or energy levels of the machine configuration 100 to make a determination of whether the machine configuration 100 and/or the host machine 110 alone has enough power to traverse one or more work cells of a potential work path based on the direction of travel. If for example the host machine 110 cannot traverse the work cell in one direction defined by the potential work path, the host machine 110 may be able to traverse the work path in the opposite direction, due to a possible change in slope. For example, if the host machine 110 were able to travel downhill, rather than uphill, the host machine 110 would not need to rely on additional power from the auxiliary machine 120, because gravity would likely provide enough assistance and may allow for charging the battery 122 of the auxiliary machine 120 through the use of regenerative braking.
The example cost analyzer 250 of
The example path selector 256 of
The example mapper 258 of
The example user interface 114, which may be used to implement the user interface 114 of
In some examples, one or more of the path planner 102, machine measurement devices 106, or user interface 150 may be geographically separated from the example machine configuration 100. For example, the path planner 102, the machine measurement devices 106, and/or the user interface 114 may be located at a central facility (e.g., a farm building near the work area). In the described example, a user may use the path generator 240 to generate potential work paths or select a work path for the machine configuration 100 to follow for a future task to be completed at the work area. In some examples, the selected path and/or potential paths may be wirelessly communicated to the machine configuration 100 via a wireless communication link (e.g., Bluetooth, wireless local area network (LAN), cellular network, etc.).
In the illustrated example of
While an example manner of implementing the path planner 102 of
A flowchart 300 representative of a process that may be implemented using example machine readable instructions stored on a tangible medium for implementing the machine monitor 242, the work area definer 244, the path definer 246, the power mode selector 252, the cost estimator 254, the cost analyzer 250, the path selector 256, the mapper 258 and/or, more generally, the path generator 240 of
As mentioned above, the example processes of
Additionally or alternatively, the example processes of
The example process 300 that may be executed to implement the path generator 240 of
The number, size, and or shape of the work cells of block 320 in
At block 330 of
At block 340 of
The following example refers to
In
A steep incline in work cells 2 and 3 for Pass 410E is a significant cost factor that may require additional power from as the auxiliary machine 120 via motor/generators 124, and therefore, the power mode selector 252 assigns an essential assist power mode to work cells 2 and 3, as indicated. In some examples, when the power mode selector 252 determines that an essential assist mode is to be implemented by the machine configuration 100 to traverse upcoming work cells, the power mode selector 252 may reassign power modes to previous work cells to ensure that the auxiliary machine 120 has enough energy stored in the battery 122 to traverse the cell. Accordingly, in the example of
In work cell 4 of the work segment 410, for Pass 410E in the example of
In work cells 5-10 of the work segment 410, for Pass 410E in the example of
Referring now to the example machine motor(s) 124100 traveling Pass 410W in the example of
In work cell 4 of the work segment 410, for Pass 410W in the example of
In work cells 3 and 2 of the work segment 410, for Pass 410W in the example of
Finally, in work cell 1 of the segment 410 for Pass 410W, the power mode selector 252 determines that the work segment 400 has a relatively flat surface, and therefore assigns a power mode of neutral, as indicated in
The illustrated example of
Referring back now to
For example, the cost estimator 254 estimates future load levels of the machine configuration 100 when the machine is to traverse each work cell of the potential work paths. As a specific example, if the machine configuration 100 has a load of ten tons, the cost estimator 254 may determine an estimated load of twelve tons for an upcoming work cell of the potential work path. Because an increase in the expected load may have an impact on fuel consumption and/or energy needed to traverse a work cell, the cost estimator 254 may adjust the costs for the machine configuration 100 to traverse that work cell based on those machine characteristics. Therefore, several factors, including measured and estimated, may be used to determine a cost for the machine configuration 100 to traverse the work cells.
In some examples, the cost estimator 254 determines the costs for the machine configuration 100 to traverse each of the cells based on the corresponding power mode selected by power mode selector 252. Table 1 below provides example energy costs for the respective power modes.
In the example of Table 1, it is assumed that the auxiliary machine 120 can generate up to 240 kW of power which may be split between traction and generation of electrical power up to 60 kW. These values are representative of agricultural tractors used for nearly total tractive activities such as tillage. Other example activities may require consideration of other power needs such as auxiliary electric loads, auxiliary mechanical loads (e.g., power take-off), and auxiliary hydraulic fluid loads. These auxiliary power needs reduce the amount of engine power available for traction and storage.
In the illustrated example of Table 1, single values for traction power and/or power for electricity generation are given for each power mode. In some example, a number of traction and/or generation splits of engine power may be used. For example, based on topography and Table 1 values, finer resolution may be obtained by assigning a slope to each power mode in the table and then interpolating traction and generation values based on actual slope at a location. Additional resolution may be obtained by increasing the dimensions considered. For example, adding soil type, soil moisture, and equipment settings such as tillage type and depth to topography.
The allocation of engine power between traction, electrical loads, mechanical loads, hydraulic loads, etc. may be based on analysis of data collected from equipment in the field, engineering calculations, simulations, etc.
Applying the above energy costs of Table 1 to the work segment 410 of
Assuming a fuel consumption of 3 gal/hr at 240 kW and an optimal speed of 5 mph to traverse each work cell, costs are calculated for traversing the work segment 410 of
Referring to Table 3, for the machine configuration 100 to traverse Pass 410E of
Accordingly, at block 350 of
At block 360, the cost analyzer 250 estimates a cost for each of the potential work paths for operating the machine configuration 100 based on the power mode associated with the machine configuration 100 in each of the work cells. In some examples, the cost analyzer 250 estimates a cost for the potential work paths by summing all costs for all cells of the work segments of the work paths, which costs may be based on alternating directions for each pass, to estimate a total cost for the potential work path (e.g., see cost analysis for
At block 370 of
Referring back to the example costs analysis from Tables 1-4, the path selector 256 compares the Totals of Tables 3 and 4, for Passes 410E, 410W of
Accordingly, at block 370 the path selector 256 selects a path based on the cost estimator 254 calculating the above costs for each of the work cells, and the cost analyzer 250 determining a total cost. Following the selection of a path at block 370, the path generator 240 has completed the path planning process.
At block 380 of
Referring now to the example of
For the following example, in
Referring to
As an example of determining the costs of traversing the work segments 410, 420, 430, of
Accordingly, for this example, totaling costs from Table 3 once (Pass 420E) and Table 4 twice (once for Pass 410W, once for Pass 430W), yields a total cost for traversing the work segments 410, 420, 430. For the second potential work path, assuming that the total costs apply in a similar fashion to work segment 410 of
Referring now to
Referring to
Referring to
In some examples, the ICE 808 may be configured to provide power mechanically to the wheels 810 of the machine 800. In such examples, the controller 804 may instruct the battery 814 to provide additional power to the motor(s) 812 when the power mode selector 222 selects a power assist mode or an essential assist mode, described herein, thus increasing an overall power output to the wheels 812. Additionally, the controller 804 may instruct the motor(s) 812 to generate energy for storage in the battery 808 when the power mode selector selects a regenerative braking mode, described herein.
The ICE 808 and generator 809 may be configured to provide electric current to the motor(s) 812 to drive/engage the wheels 810. In such examples, when the power mode selector 222 selects power assist mode or essential assist mode, as described herein, the controller 804 may instruct any wheels that are free-wheeling to engage/drive in order to provide additional traction and/or payload power. The controller 804 may instruct the motor(s) 112 to enter a regenerative braking mode according to the power mode selector 222, in which case the motor(s) 112 generate energy for storage in the battery 814.
The system 900 of the instant example includes a processor 912. For example, the processor 912 can be implemented by one or more microprocessors or controllers from any desired family or manufacturer.
The processor 912 includes a local memory 913 (e.g., a cache) and is in communication with a main memory including a volatile memory 914 and a non-volatile memory 916 via a bus 918. The volatile memory 914 may be implemented by Synchronous Dynamic Random Access Memory (SDRAM), Dynamic Random Access Memory (DRAM), RAMBUS Dynamic Random Access Memory (RDRAM) and/or any other type of random access memory device. The non-volatile memory 916 may be implemented by flash memory and/or any other desired type of memory device. Access to the main memory 914, 916 is controlled by a memory controller.
The processor platform 900 also includes an interface circuit 920. The interface circuit 920 may be implemented by any type of interface standard, such as an Ethernet interface, a universal serial bus (USB), and/or a PCI express interface.
One or more input devices 922 are connected to the interface circuit 920. The input device(s) 922 permit a user to enter data and commands into the processor 912. The input device(s) can be implemented by, for example, a keyboard, a mouse, a touchscreen, a track-pad, a trackball, isopoint and/or a voice recognition system.
One or more output devices 924 are also connected to the interface circuit 920. The output devices 924 can be implemented, for example, by display devices (e.g., a liquid crystal display, a cathode ray tube display (CRT), a printer and/or speakers). The interface circuit 920, thus, typically includes a graphics driver card.
The interface circuit 920 also includes a communication device such as a modem or network interface card to facilitate exchange of data with external computers via a network 926 (e.g., an Ethernet connection, a digital subscriber line (DSL), a telephone line, coaxial cable, a cellular telephone system, etc.).
The processor platform 900 also includes one or more mass storage devices 928 for storing software and data. Examples of such mass storage devices 928 include floppy disk drives, hard drive disks, compact disk drives and digital versatile disk (DVD) drives.
The coded instructions 932, which may implement the coded instructions 300 of
From the foregoing, it will be appreciated that the above disclosed methods, apparatus and articles of manufacture provide a method and apparatus for selecting an path for one or more machines to traverse a work area defined by work cells, wherein the one or more machines have electric drives with the ability to charge, provide power, or free wheel through the work cells depending on cost factors associated with both the work area and the machine itself.
Although certain example methods, apparatus and articles of manufacture have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus and articles of manufacture fairly falling within the scope of the claims of this patent.