CA2588269A1 - Method and apparatus for patterned turf cutting - Google Patents
Method and apparatus for patterned turf cutting Download PDFInfo
- Publication number
- CA2588269A1 CA2588269A1 CA 2588269 CA2588269A CA2588269A1 CA 2588269 A1 CA2588269 A1 CA 2588269A1 CA 2588269 CA2588269 CA 2588269 CA 2588269 A CA2588269 A CA 2588269A CA 2588269 A1 CA2588269 A1 CA 2588269A1
- Authority
- CA
- Canada
- Prior art keywords
- mower
- cutting path
- cutting
- control system
- conduit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- A—HUMAN NECESSITIES
- A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
- A01D—HARVESTING; MOWING
- A01D34/00—Mowers; Mowing apparatus of harvesters
- A01D34/006—Control or measuring arrangements
- A01D34/008—Control or measuring arrangements for automated or remotely controlled operation
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Environmental Sciences (AREA)
- Harvester Elements (AREA)
Description
METHOD AND APPARATUS FOR PATTERNED TURF CUTI'ING
This invention is in the field of turf mowing apparatuses and methods and more panicularly ta a method and apparatus for automatically guiding a mower in order to cut a pattem into the turf of a field.
BACKGROUND
to Golf course, baseball fields and other sporting fields have large expanses of lawn or turf and it has become popular to cut these large areas into a pattern to provide a more professional appearing turf surface. In the simplest patterns, this pattemed turf cutting can consist of parallel stripes mowed into the lawn surface where the color of the grass alternates between adjacent stripes. More complex pattems involve checkerboard and 0 diamond patterns and it is not uncommon to find even more complex cuts involving curves and other cuts.
These pattem.s appear as alternating colorcd "stripes" caused by the light reflecting off of the blades of the grass. When a blade of grass is bent away from a view, light reflects off 20 the wide, lengthy part of the blade of grass, causing the blade of glass to appear lighter in color. Therefore, a stripe or row of mown grass that is bent away a viewer will appear lighter. When a blade of grass is bent towards a viewer, more of the tip of the grass is facing the viewer causing less reflective surface of the grass blade to be facing the viewer and the stripe of grass well appear darker to the viewer. Therefore, a stripe or row of mown grass that is bent towards a viewer will appear darker than a stripe or row of mown grass that is bent away from the viewer. By alternating the direction grass is bent in adjacent stripes or rows, the appearance of alternating stripes of lighter and darker grass can be achieved and this is what allows a person mowing the grass to create a pattetn in the mown turf.
To form these stripes or rows, lawn or turf is bent in a specific direction by mowing it in that direction. By alterrtating the direction that grass is mowed in, i.e. one stripe mowed io in a north direction and an adjacent stripe mowed in a south direction, the appearance of different colored stripes is achieved.
Mowers equipped with mower reels tend to bend the grass being cut in a single direction as a result of the operation of the cutting reel, however, it is also cornmon for a mower to be equipped with a lawn striper tool to further bend the stalks of grass in a particular direction. As opposed to a cutting blade that bends the grass stalks in conjunction with cutting the grass stalks, a lawn striper simply further bends the stalks of grass towards the ground enhancing the appears of striping in the grass surface.
While the principles and theory behind cutting a grass surface into a pattern is well-known, the implementation of it is hardly easy or straightforward. In theory, all it requires to cut a pattem into a field surface is to mow the field surface in alternating directions. However, in practice, it is much more complex and difficult than this. Often, highly expcrienced cutters are necessary to get the pattern just right and it is typically oniy exclusive or professional fields that presently use patterned turf cutting, such as major league baseball fields and upscale golf courses.
There are a number of reasons why pattemed turf cutting is presently not conunon on more sporting and other fields. While on smaller fields in may be easier to achieve relatively straight lines, when the cutting patterns are applied to relatively large fields such as golf courses and baseball fields it is quite difficult to keep the lines straight enough so that the lines do not appear wavy. While applying the pattern to a large field greatly enhances the appearance of the pattern, it creates some problems with getting the "stripes" or pattetn looking straight. Small deviations in a straight cutting line will often mar the whole effect and by a cutter who accidentally deviates from a straight line can often adversely affect the "profe,ssional" look of the pattem. In addition, because an operator of a mowcr tcnds to follow the lines of a prcvious cutting path, small deviations in a first path can cause serious deviations in later adjacent paths, where the operator has used the first path as a guide for cutting the adjacent paths. It takes a very experienced cutter to be able to drive a mower in a straight line in order to achieve the pattem and often the cutter must concentrate fairly intensely for long periods of time to get the pattern to appear straight because with such large mown turf surfaces evcn relatively 2o small deviations can mar the overall effect of the pattern.
Additionally, when the patterns become more complex it is often hard for an operator of a mower to determine where exactly he or she is on the pattem. While from a bird's eye view or standing at one end of a field, it is easy to visualize the overall cutting pattem in a field, it is often quite difficult if not impossible for an operator of a mower in the middle of the field to figure out where in the pattern he or she is and where he or she should go frorn any given spot. This problem is exasperated by the fact that that bent blades of grass often do not appear as vivid in the midst of them as they do when standing at a distance. A person standing on a stripe will not be able to see the stripe as easily as a person standing further away. Often the pattern around the mowers is barely visible to the operator of the mower, if he or she is even able to see the pattern at all. This requires an experienced cutter to visualize the "design" or pattern in his or her mind when cutting the grass stnface and to he able to guide the mower based on the memorized design. This is why patterns such as stripes, checkerboard and diamond are the most commonly seen cutting patterns, with pattems involving curvcs and more intricate cuts reserved for special occasions.
SUNLMARY OF THE IIVVENTION
It is an object of the present invention to provide a systent and method that overcomes problems in the prior art.
The present invention comprises a system and method for directing a mower along a cutting path wherein the cutting path will result in a predetermined pattem to be cut into the surface of a field.
A control system is provided that is operative to store a cutting path in its memory.
When the mower follows the cutting path to cut a field, a pattern is cut into the field, such as altemating stripes, checkerboard or diamonds. The mower begins cutting a field at a starting point on the cutting path and as the mower progresses along the cutting path, the control system will repeatedly determine the position of the mower and compare the mower's actual position to the desired cutting path. If the mower has deviated from the cutting path, the control system will transrnit a correction control signal.
The correction control signal will depend on whether the mower has deviated to the right or left of the 1o desired cutting path. If the if the mower has deviated to the right of the desired cutting path the correction control signal will indicate that the mower must be turned left to once again follow the desired cutting path, and vice versa.
In a first embodiment of the invention, the control system is operatively connected to an automatic steering system. When the control system determincs that the mower is deviating from the desired cutting path, the correction control signal is transmitted to the automatic steering system and the mower is automatically steered in the direction necessary for the mower to once again follow the desired cutting path.
In a second embodiment of the invention, the control system is operatively connected to a user display comprising a left indicator light and a right indicator light.
When the control system detcnnines that the mower is deviating frorn the desired cutting path to the iight of the desired cutting path, a correction control signal is transmitted to the user display and the left indicator light is lit to indicate to the user that he or she should manually turn the mower to the left to regain the desired cutting path and vice versa.
As the mower progresses along the cutting path the control system will continue to check the actual position of the mower against the desircd cutting path and when the cutting path has been completed the mower will be fmished mowing the field.
In this manner, the cutting paths can be generated so that by the mower following the cutting path a pattern such as altemating stripes, checkerboard, diamonds or even a more i0 intricate design can be mowed into the surface of the field. Rather than requiring the operator of the mower to attempt to keep the overall design in his or her memory and figuring out what paths to follow with the mower, in the first embodiment of the invention, the mower can be automatically steered by the control system to make the desired pattem or in the second embodiment of the invention, the operator of the mower is simply by directed by the control system how to steer to result in the desired pattern.
The operator does not need to be able to visualize or even plan the design in his or her head. Rather, the design is cut in the surface of a lawn at the direction of the c.~ontrol systern.
2o DESCRIPTION OF THE DRAWINC'S
While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
Fig. 1 is a perspective view of a mower, as is commonly known in the art;
Fig. 2 is a schematic illustration of a conventional hydrostatic drive system;
Fig. 3 is a schematic illustration of an automatic steering system for a mower with a hydrostatic drive, in accordance with a first embodiment of the present invention;
Fig. 4 is a schematic illustration of the automatic steering system of Fig. 3, incorporated into the hydrostatic drive system of Fig. 2;
Fig. 5 is a schematic illustration of a control system in accordance with the present invention;
Fig. 6 is a flowchart of a software process for creating a cutting path for use in guiding a mower along the cutting path to cut a field into a desired pattern;
Fig. 7 is an illustration of a sample of a field map representing a fairway on a golf course for use in the process illustrated in Fig. 6;
Fig. 8A illustrates an altemating stripe pattem;
Fig. 8B illustrates a checkerboard pattem;
Fig. 8C illustrates a diamond pattern;
Fig. 9 is a diagram a cutting path overlaid on a portion of a field map of a fairway wherein following ehe cutting path with a mower will rcsult in a diamond pattern;
Fig. 10 is a schematic illustration of a conventional computer system;
Fig. 11 is a flow chart of a cutting path process for mowing a field in a specified cutting pattern; and Fig. 12 is an illustration of a user display in accordance with a second embodiment of the present invention.
DETAILED DES(.'RIPTION OF THE ILLUSTRATED EMB4DIME'.~1TS
Fig. 1 is a perspective view of a mower that can be used to implement a system and method in accordance with the present invention. Mower 10 is a typical commercial grass mower for cutting the grass on the fairways of golf courses and comprises: a number of cutting reels 12; a left drive wheel 14; a right drive wheel 16;
operator's seat 11; and steering controls 70.
Cutting reels 12 cut the grass to a desired length. The mower 10 is driven by left drive wheel 14 and right drive wheel 16, which are hydrostatically steered and driven by a hydrostatic drive (not shown). An operator sitting in the operator's seat I1 has access to the steering controls 70 and can steer the mower 10.
The Conventional Hydrostatic Steering System of a Commercial Mower Fig. 2 is a schematic illustration of a conventional hydrostatic drive system, such as the hydrostatic drive system that would be incorporated into mower 10, in Fig. 1.
The hydrostatic drive system 50 comprises: a right hydraulic motor 44; a left hydraulic motor 42; a right drive conduit 34; a right return conduit 36; a left drive conduit 32; a left return conduit 37; a valve block 55; a tank 60; a pump 65 and steering controls 70.
In typical operation of the hydrostatic drive system 50, hydraulic fluid from the tank 60 will be pressurized by the pump 65 and the pressurized hydraulic fluid routed to the valve block 55. From the valve block 55, this pressurized hydraulic fluid is routed through the right drive conduit 34 to the right hydraulic motor 44 to drive a right drive wheel 16, as shown in Fig. 1, connected to the right hydraulic motor 44. From the right hydraulic motor 44, the hydraulic fluid is routed back to the routing valve 55 through a right return conduit 36. To drive a left drive wheel 14, as shown in Fig. 1, the pressurized hydraulic fluid is routed through the left drive conduit 32, by the valve block 55, to the left hydraulic motor 42. From the left hydraulic motor 42, the hydraulic fluid is routed back to the routing valve 155 through the left return conduit 37.
An operator controls the mower by entering inputs into the steering controls 70. The steering controls 70 controls the distribution of the flow of the hydraulic fluid by the valve block 55, as commonly known in the art. Based on the operator's steering inputs, the vaive block 55 varies the flow of pressurized fluid to the right wheel hydraulic motor 44 and the left wheel hydraulic motor 42. When an equal flow of hydraulic fluid is provided to the right wheel hydraulic motor 44 and the left wheel hydraulic motor 42, the mower will move in a straight direction of travel. By increasing the flow of pressurized hydraulic fluid to the right wheel hydraulic motor 44, so that more hydraulic fluid is flowing to the right wheel hydraulic motor 44 than the left wheel hydraulic motor 42, the right wheel of the mower is rotated faster than the left wheel causing the mower to tum to the left. Steering the mower to the right is accomplished by increasing the flow of 13 pressurized hydraulic fluid to the left hydraulic motor 42 relative to the right hydraulic motor 44.
Alternatively, the mower can also be tumed by reducing the flow of hydraulic flow to either the right hydraulic motor 44 or the left hydraulic motor 42. For example, the mower can be turned left by left by reducing the aniount of hydraulic fluid flowing to the left wheel hydraulic motor 42 causing the right wheel to rotate faster relative to the left wheel and thereby causing the mower to turn left.
The Auto-steering Components of the Steering System Fig. 3 schematically illustrates an automatic steering system 100 for a mower, in accordance with a first embodiment of the present invention wherein the mower is automatically steered by a control system 300 over part of a cutting path or an entire cutting path by means of control signals received from the control systern 300. The steering system 100 comprises: a left diverting conduit 102, a left tee connection 103; a right diverting conduit 104, a right tee connection 105; a control circuit 110; and a return conduit 120. Generally, although not necessarily, a right flowrate valve 112 and left flowrate valve 114 can also be provided to allow the flowrate of hydraulic flow in the 1o right diverting conduit 104 and left diverting conduit 102 to be adjusted.
Fig. 4 is a schematic illustration of the automatic steering system 100, illustrated in Fig.
3, incorporated into the hydrostatic drive system 50, illustrated in Fig. 2.
The left diverting conduit 102 is operative to contain a flow of hydraulic fluid and is connected into the left drive conduit 32, typically using the left tee connection 103, such that the left divening conduit 102 is operative to divert a portion of a flow of hydraulic fluid out of or away from the left drive conduit 32 so that the portion of the hydraulic fluid that is diverted by the left divert conduit 102 does not drive the left hydraulic motor 42. The right diverting conduit 104 is operative to contain a flow of hydraulic fluid and is connected into the right drive conduit 34, typically using the right tee connection 105, such that the right drive diverting conduit 104 is operative to divert a portion of a flow of hydraulic fluid out of or away from the right drive conduit 34 so that the portion of the hydraulic fluid that is diverted by the right divert conduit 104 does not drive the right hydraulic motor 44.
The control circuit 110 is typically an open center solenoid valve operative to control the flow of hydraulic fluid through the right diverting conduit 104 and the left diverting conduit 102. The control circuit 110, in response a control signal from a control system 300, can open a flowpath and route a flow of hydraulic fluid through either the right diverting conduit 104 or left diverting conduit 102 to the return conduit 120 and back to the tank 60. Although Figs. 2 and 3 show the control circuit 110 as being connected to to both the right divcrting conduit 104 and the left diverting conduit 102, it would be understood by a person skilled in the art that there could be a separate control circuit 110 for each of the right diverting conduit 104 and left diverting conduit 102 and that a single control circuit does not necessarily have to be used to control the flow through both Ihe right diverting conduit 104 and left diverting conduit 102.
The control circuit 110 could comprise one or more valves that simple open or shut a flow path through the control circuit 110 to the return conduit 120 and the control circuit 110 simply routes hydraulic fluid flow through either the right diverting conduit 104 or left diverting conduit 102, for a period of time, to control the steering of the vehicle.
Optionally, if the control circuit 110 simply either stops all flow of hydraulic fluid in the right diverting conduit 104 and the left diverting conduit 102 or opens a fluid flowpath for the right diverting conduit 104 or left diverting conduit 102, the right flowrate valve 112 and left flowrate valve 114 could be used to adjust the flowrate of hydraulic fluid through the right diverting conduit 104 and left diverting conduit 102 when a flow path is opened by the control circuit 110, thereby adjusting the turning rate caused by the steering system 100. The right flowrate valve 112 and left flowrate valve 114 are adjustable flowrate valves that can be adjusted for a set flow rate.
Typically, the right flowrate valve 112 and the left flowrate valve 114 are manually adjustable needle valves allowing the flowrates in the right diverting conduit 104 and the left diverting conduit 102 to be adjusted.
Alternatively, the control circuit 110 could comprise a proportional valve system and the control circuit 110 could be operative to allow varying amounts of fluid flow through the right diverting conduit 104 and the left diverting conduit 102.
The steering system 100 of the present invcntion allows a control systeni 300 to steer a vehicle with a hydrostatic drive, independent of steering inputs from an operator of the vehicle. By inducing hydraulic fluid flow through the right diverting conduit 104, hydraulic fluid flow is diverted away from the right hydraulic motor 44. By reducing the flow of hydraulic fluid to the right hydraulic motor 44, the rotational speed of a right wheel 16, as shown in Fig. 1, being driven by the right hydraulic motor 44 is reduced and the mower wili turn towards the right. Altematively by inducing hydraulic fluid flow through the left diverting conduit 102, hydraulic fluid flow is diverted away from the left hydraulic motor 42, which will in tutn reduce the flow of hydraulic fluid to the left hydraulic motor 42 and cause the mower to turn to the left.
Hydraulic fluid routed through the right diverting conduit 102 or left diverting conduit 104, by the control circuit 110, is passed back through the return line 120 to the hydraulic fluid tank 60 where it can be rcturned to the pump 65 and reused in the hydrostatic drive system 50. Again, although Figs. 2 and 3 illustrate a single control circuit 110 controlling the flow of hydraulic fluid through the right diverting conduit 104 and the left diverting conduit 102, if a separate control circuit was provided for each of the right diverting conduit 104 and left diverting conduit 102, a separate return line connected to each of the right diverting conduit 4 and the left diverting conduit 102 and retuming to the tank 60 could be used, so that the right diverting conduit 104 and the left diverting conduit 102 do not have to be in relatively close physical proximity and connected to a signal eontral circuit 110.
The Control System Fig. 5 illustrates a control system 300 in accordance with the present invention, that is operative to determine when a mower is deviating from a desired cutting path and transmit correction control signals in response to the mower deviating from the desired cutting path. Control system 300 comprises: a processing unit 310, such as a microprocessor; a GPS receiver 320, operative to determine a position based on GPS
signais; a memory 330, for storage of data; and an input/output interface 340.
Generally, althouglt not necessarily the control system 300 can also incorporate a gyroscopic position unit 350 that uses gyroscopes to determine a direction of travel.
While Fig. 5 illustrates a control system 300 that uses a GPS receiver 320 to determine the position of the vehicle, it is contemplated that the control system 300 could use any type of method for dctermining its position such as dead reckoning, beacon referencing, etc.
The control system 300 is operative to compare an actual position of a mower against a desired cutting path stored in the memory 330 of the control system and transmit correction signals from the input/output interface 340 when the mower has deviated from the desired cutting path. As the mowcr is in operation, the control system 300 will repeatedly receive GPS signals using the GPS receiver 320 and determine the position of the mower. The processing unit 310 will compare the determined position of the vehicle -o with the desired cutting path, to determine if the mower is following the cutting path or if the mower has deviated from the cutting path. Additionally, if the control system 300 comprises a gyroscopic position unit 350, the processing unit 310 will be able to determine the direction of travel of the mower and predict whether the direction of travel will cause the mower to leave the desired cutting path.
When the control system 300 determines that the mower has left the desired cutting path, the control system 300 transmits a correction control signal in order to alter the direction of travel of the mower. Upon the processing unit 310 determining that the mower is not on or is leaving the cutting path, the processing unit 310 will determine which way the mower has to be steered to either keep following the desired cutting path or to get the mower back on the cutting path, and the processing unit 310 will send a correction control signal through thc input/output interface 340.
In a first embodiment of the invention, the correction control signal is transmitted to the stecring system 100, of Fig. 3, in order to automatically steer the mower back to the desired cutting path. The correction control signal is transmitted by the control system 300 to the steering system 100 and to the control circuit 110. Depending upon whether the control system 300 determines that the mower is deviating from a desired cutting path in either a right or left direction, the correction control signal transmitted to the control circuit 110 will open a flow path for either the right diverting conduit 102 or left diverting conduit 102, causing the mower to turn to either the left or right respectively.
The correction control signal transmitted from the control system 300 to the control circuit 110 is typically in the form of a voltage input. When the control circuit 110 receives a voltage input from the control system 300, the control circuit opens a flow path and causes hydraulic fluid to flow through either the right diverting conduit 104 or left diverting conduit 102, until the voltage input stops. The control system 300 turns the t5 vehicle to the right by sending a control signal to the control circuit 110 to open a flowpath for the right diverting conduit 104, causing the right diverting conduit 104 to route a portion of the hydraulic fluid flow away from the right hydraulic motor 44 and tums the vehicle to the left by sending a control signal to the control circuit 110 to open a flowpath for the left diverting conduit 102, causing the left diverting conduit 102 to route a portion of the hydraulic fluid flow away from the left hydraulic motor 42.
Whcn the control system comprises a valve system that is either open or shut valves, the rate of tuming can be altered by the sizing of the valve or valves in the valve system.
Using a larger valve or valves will divert more hydraulic fluid flow away from the hydraulic motors causing the vehicle to turn faster when the valves are opened.
Alternatively, the right flowrate valve 112 and left flowrate valve 114 can be uscd to adjust the flowrate in the right diverting conduit 104 and the left diverting conduit 102 thereby altering the flowrate of hydraulic fluid flow way from the hydraulic motor and allowing the turning rate of the steering system 100 to be adjusted.
Altcrnativcly, control circuit 110 can comprise a proportional valve or valves operative to open various amounts in response to control signals from the control system 300. For example, these control signals can be digital signals or analog signals specifying the degree of opening of the valve that is desired, whereby the amount the proportional valve opens will he based on the control signal from the control system 300. In this manner, the control system 300 would also be able to control the flowrate of hydraulic fluid through the right diverting conduit 104 and left diverting conduit 102 and in turn the turning rate of the vehicle. When the vehicle is oi>ly slightly deviating from the desired path, the control system 300 may only open the proportional valve or valves a slight amount to turn the vehicle slowly. Alternatively, if the vehicle is deviating significantly from the desired path, the control system 300 could open the proportional valve or valves a greater amount to cause the rate of turning of the vehicle to be greater.
In a second embodiment of the invention, the correction control signal will be transmitted to a user display 700, illustrated in Fig. 12. The user display 700 comprises a left indicator light 710 and a right indicator light 720. Depending upon whether the control system 300 determines that the mower is deviating from a desired cutting path in either a right or left direction, the correction control signal transmitted to the user display 700 will indicate to an operator which way to steer the mower, by lighting the left indicator light 710 or right indicator light 720, respectively. The user will then steer the mower in the indicated direction.
Referring again to Fig. 5, the control system 300 will continue to detennine the position of the mower in relation to the cutting path as the mower turns and once t.he mower has moved back to the cutting path the control system 300 will stop sending a control signal to to get the mower once again following the cutting path. Typically, a small correction signal operative to turn the mower in the opposit.c direction is required, when the mower is once again on the cutting path, in order to straighten out the mower on the cutting path.
The cutting path stored in memory 330 of the control system 300 determines the path of travel followed by the mower. In the first embodiment of the invention, the mower can be automatically steered, by the control system 300, along relatively straight parts of the cutting path. When a sharp corner is approached, the control system 300 can indicate to a user to turn and an operator then uses the steering controls 70 to change the direction of the mower. Once the mower is once again facing a relatively straight part of the cutting path, the control system 300 resumes automatically steering the mower.
Alternatively, the control system 300 could be given complete control of the mower, with the control system 300 steering the mower along the entire desired cutting path 330, including any relatively sharp turns, with the operator only required to intervene and use the steering controls 70 in the event of an emergency.
Creating a Cutting Path For the mower to mow a pattern into the turf of a field, the cutting path must be created that will result in the desired pattem. Fig. 6 is a flowchart of a software process 400 for creating a cutting path for use in guiding a mower along the cutting path to cut a field into a desired pattern. Process 400 comprises the steps of: starting 405; loading a map of thc field into memory 410; determining a pattern 420; determining the number of mowers t0 430; overlaying cutting path on the field map 440; and finishing 450.
The method starts 405 and a map of the field to be cut is loaded into memory 410. The field map will be a map of the field to be cut in accurate scaled dimensions and displaying any impediments in the field. It can either be selected from a number of pre-existing field maps in memory or it can be created and loaded for the first time. For example, if the field to be cut is a baseball diamond, the field map will show the dimensions of the outfield to scale along with the start of the infield, the pitchers mound, etc. If the field to be cut is a hole of a golf course, the shape of the hole will have the shape fairway to scale and indicate the cart path, any hazards such as sand traps, water hazards, etc., the grcen and any trccs or shrubs that may appear on the fairway.
Fig. 7 illustrates a sample of a field map 460 representing a fair way on a golf course.
Field map 460 will he rendered to scale and will indicate the relative dimensions of the fair way 465, any water hazards 470, sand trap 475, shrubs 480 and the green 490.
Referring again to Fig. 6, the next step will be to determine a cutting pattertt 420. For example, alternating stripes, checkerboard pattem, diamond pattem, etc. could be chosen, as illustrated in Figs. 8A, 8B and 8C, respectively. If these relatively simple designs are chosen, the pattem could be applied to the field in a repetitive manner until the entire field was covered. Alternatively, if the design is a more complex pattern, it may be i o custom designed for a field.
Next, the number of mowers is determined 430. One mower alone can be used to cut the fields. Altematively, more than one mower could be used to achieve the same result quicker. Additionally, one mower may be used for cutting and a second mower may be used without cutting blades, with only a striper toot to bend the grass.
Finally, the ctrtting pattem will be overlaid on the file map 440. A cutting paths to be followed by the mower will be determined using the cutting width of the inower, the dimensions of the field to be cut, the desired pattern to be cut by the mower and the number of mowers to be used. If the pattem selected is a relatively simple pattem such as aiternating lines, checkerboard or diamonds, the pattetn can be repeatedly overlaid on the field map. However, if the design is more complex or non-repeating, it may have to be superimposed on the field map in a large open area and optionally a repetitive pattern used to fill in the edges. If more than one mower is used, the cutting paths will be divided and each mower will be given half of the cutting paths so that both of the mowers cut a complete pattetn when working in conjunction.
Fig. 9 illustrates a cutting path overlaid on a portion of a field map of a fairway wherein following the cutting path with a mower will result in a diamond pattem. The cutting path with make a first cutting path 485 diagonal across the length of the fairway and a second cutting path 490 going diagonal in the other direction across the fairway. By having a mower follow the first cutting path 485 and then the second cutting path 490 a to diamond pattern will be mowed into the fairway. Alternatively, a first mower can be programmed with the first cutting path 485 and a second mower can be programmed with the second cutting path 490. Together the first and second mowers cutting in conjunction will create a diamond pattetn in the mowed fairway.
Referring again to Fig. 6, once the process is completed, a field map of the area to be cut with the cutting paths overlaid on the field map will have been created and the method will finish 450.
In one embodiment of the invention, the software process 400 is run on the control system 300, as shown in Fig. 5. The steps of the process 400 and stored field maps are saved in memory 330 and are implemented by the processing unit 310. A user will make selections for the field map, number of mowers, cutting patterrt, etc. on a display device and interface device (not shown). This embodiment might be particularly useful for such fields as baseball fields or a golf course, where the field maps will not change from time to time or there is a finite number of field maps to choose from, such as an 18 hole golf course and the cutting pattems applied to the ficlds are relatively simple and can be drawn over the existing field maps quite easily.
In an altemative embodiment, the process 400 is implemented on a conventional computer system 500, schematically illustrated in Fig. 10. Conventional computer systcm 500 is suitable for supporting the operation of the process 400 of the present invention. The conventional computer system 500 typically comprises: a processing unit l0 503; a memory storage device 504; an input device 505; a display device 507; and a program module 508.
The processing unit 503 can be any processing unit that is typically known in the art with the capacity to run the program and is operatively connected to the memory storage device 504 such as a local hard-disk, etc. The input device 505 can be any suitable device suitable for inputting data into the computer system 501, such as a keyboard, mouse or data port such as a network connection and is coupled to the processing unit 503 and operative to allow the proccssing unit 503 to receive inforrnation from the input device 505. The display device 507 can be any suitable device coupled to the processing unit 503 and operative for displaying data. The program module 508 is stored in the memory storage device 504 and operative to provide instructions to processing unit 503 to implement the process 400 and the processing unit 503 responsive to the instructions of the program module 508.
Although other intemal components of a computer system 501 are not illustrated, those of ordinary skill in the art will appreciate that many more components and interconnections between them are well known and can be used. As well the computer system 501 need not be limited to only one computer system and may comprise a network of connected computer systems.
By using conventional computer systcm 500, a user would have more flexibility to generate more complex cutting pattetns and apply them to more custonvzed fields, in order to generate a cutting path. Once the cutting path has been generated and stored, it can be saved onto some transportable media and the saved cutting path can be used in control system 300 to have a mower follow the control path.
Directing a Mower to Mow a Pattern into the Turf of a Field Fig. 11 is a flow chart of a cutting path process 600 for mowing a field in a specified cutting pattern. The process 600 comprises: starting 602; loading a cutting path 605;
guiding the mower to a starting point 608; and repeatedly; determining the position of the cutter 610; comparing the position of the mower to the cutting path 620; and transmitting correction control signals to steer the mower if it deviating from the cutting path 640.
The cutting process 600 will start 602 and a cutting path will be loaded 605 into the memory 330 of the control system 300. The cutting path will be a cutting path that has been created using the proccss 400, illustrated in Fig. 6.
Once the cutting path has been loaded 605, a starting point for the control path will be determined and the user will be guided to a starting point 608. The starting point will correspond to a start of a cutting path on the field map.
The operator of the mower will then start the mower moving. As the mower is moving, the control system 300 will guide the mower along the cutting path, by repeatedly determining a position 610, comparing the position to the cutting path 620;
and transmitting correction control signals to steer the mower if it is deviating from its cutting path 640.
For each of these repetitions, the position of the mower is determined 610.
Referring to Fig. 5, the syst.em will repeatedly determine the posilion of the cutter 610.
The processing unit 310 of the control system 300 collects position coordinates for the position of the control system 300 from the GPS receiver 320.
Referting again to Fig. 11, next, the coordinates of the mower will be compared to the cutting path. Referring to Fig. 5, the processing unit 3l0 of the control system 300 compares the coordinates from the GPS receiver 320 to the cutting path stored in the memory 330.
Referring again to Fig. 11, whether or not the mower is on the cutting path will be determined and if the mower is following the cutting path, the method will check to see whether the cutting path is completed 635 and the process will once again dctermine the position of the mower and follow steps 620. 630, etc, if the cutting path has not been completed.
Alternatively, if at 630, it is determined that the mower is no longer on the cutting path, correction signals are transmitted 640 to steer the mower back to the cutting path.
Referring to Fig. 5, when the control system 300 determines that the mower is deviating from the cutting path, the processing unit 310 determines which way the vehicle hat to be steered, based on the position of the mower in relation to the desired cutting path, and the processing unit 310 will send a control signal through the input/output interface 340.
In the first embodiment of the invention, the mower, being used to mow the field, is equipped with the automatic steering system 100, illustrated in Fig. 3, and the control signal transmitted by the control system 300 to the steering system 100 will be transmitted to the control circuit 110 to automatically steer the mower in absence of any input from the operator using the operators controls 70. The control system 300 will determine whether the mower is deviating from the cutting path in either a right or left direction and provide a corresponding control signal to the control circuit 110 to steer the mower back to the cutting path. Based on the control signal, the control circuit 110 will open a flow path for either the right diverting conduit 102 or left diverting conduit 102, causing the mower to turn in the opposite direction back towards the cutting path.
In the second embodiment of the invention, the control signal transmitted through the input/output interface 340 of the control system 300 will be transmitted to a user display 700 as illustrated in Fig. 12 and used to light either a left indicator light 710 or a right indicator light 720. If the control system 300 determines that mower is deviating from the cutting path by drifting to the right of the cutting path, the control signal will activate a left indicator light 710 on the user display 700 to indicate to a user to manually turn the mower to the left to return to the cutting path. If the control system 300 determines that the mower is deviating to the left of the cutting path, the control signal will activate a right indicator light 720 on the user display to indicate to a uscr to manually turn the lo mower to the right to return to the cutting path.
Referring again to Fig. 11, as the mower is moving back to the cutting path, the process 600 will continue to determine the position of the mower 610, compare the coordinates to the cutting path 620 and until the mower is back on the cutting path, the control signal i will continue to be transmitted 640. Once the mower has moved back to the cutting path, when the position of the mower is determined 6l0 and the positioned compared to the cutting path 620, the mower will be determined to be on the path 630 and the control signal will stop being transmitted.
2o As the mower progresses along the cutting path, steps 610, 620, 630, 635 (and when required step 640) will continually be repeated until the mowcr has completed the cutting path, at which time the field will be cut and cutting process 600 will end 650.
Although a system of the present invention can easily be incorporated as original equipment, so that a mower could be manufactured with the control system 300 and, optionally, the steering system 50, outlined herein. Alternatively, the control system could be provided as an aftermarket kit to be added to an existing mower.
The foregoing is considered as illustrativc only of the principles of the invention.
Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in io structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
This invention is in the field of turf mowing apparatuses and methods and more panicularly ta a method and apparatus for automatically guiding a mower in order to cut a pattem into the turf of a field.
BACKGROUND
to Golf course, baseball fields and other sporting fields have large expanses of lawn or turf and it has become popular to cut these large areas into a pattern to provide a more professional appearing turf surface. In the simplest patterns, this pattemed turf cutting can consist of parallel stripes mowed into the lawn surface where the color of the grass alternates between adjacent stripes. More complex pattems involve checkerboard and 0 diamond patterns and it is not uncommon to find even more complex cuts involving curves and other cuts.
These pattem.s appear as alternating colorcd "stripes" caused by the light reflecting off of the blades of the grass. When a blade of grass is bent away from a view, light reflects off 20 the wide, lengthy part of the blade of grass, causing the blade of glass to appear lighter in color. Therefore, a stripe or row of mown grass that is bent away a viewer will appear lighter. When a blade of grass is bent towards a viewer, more of the tip of the grass is facing the viewer causing less reflective surface of the grass blade to be facing the viewer and the stripe of grass well appear darker to the viewer. Therefore, a stripe or row of mown grass that is bent towards a viewer will appear darker than a stripe or row of mown grass that is bent away from the viewer. By alternating the direction grass is bent in adjacent stripes or rows, the appearance of alternating stripes of lighter and darker grass can be achieved and this is what allows a person mowing the grass to create a pattetn in the mown turf.
To form these stripes or rows, lawn or turf is bent in a specific direction by mowing it in that direction. By alterrtating the direction that grass is mowed in, i.e. one stripe mowed io in a north direction and an adjacent stripe mowed in a south direction, the appearance of different colored stripes is achieved.
Mowers equipped with mower reels tend to bend the grass being cut in a single direction as a result of the operation of the cutting reel, however, it is also cornmon for a mower to be equipped with a lawn striper tool to further bend the stalks of grass in a particular direction. As opposed to a cutting blade that bends the grass stalks in conjunction with cutting the grass stalks, a lawn striper simply further bends the stalks of grass towards the ground enhancing the appears of striping in the grass surface.
While the principles and theory behind cutting a grass surface into a pattern is well-known, the implementation of it is hardly easy or straightforward. In theory, all it requires to cut a pattem into a field surface is to mow the field surface in alternating directions. However, in practice, it is much more complex and difficult than this. Often, highly expcrienced cutters are necessary to get the pattern just right and it is typically oniy exclusive or professional fields that presently use patterned turf cutting, such as major league baseball fields and upscale golf courses.
There are a number of reasons why pattemed turf cutting is presently not conunon on more sporting and other fields. While on smaller fields in may be easier to achieve relatively straight lines, when the cutting patterns are applied to relatively large fields such as golf courses and baseball fields it is quite difficult to keep the lines straight enough so that the lines do not appear wavy. While applying the pattern to a large field greatly enhances the appearance of the pattern, it creates some problems with getting the "stripes" or pattetn looking straight. Small deviations in a straight cutting line will often mar the whole effect and by a cutter who accidentally deviates from a straight line can often adversely affect the "profe,ssional" look of the pattem. In addition, because an operator of a mowcr tcnds to follow the lines of a prcvious cutting path, small deviations in a first path can cause serious deviations in later adjacent paths, where the operator has used the first path as a guide for cutting the adjacent paths. It takes a very experienced cutter to be able to drive a mower in a straight line in order to achieve the pattem and often the cutter must concentrate fairly intensely for long periods of time to get the pattern to appear straight because with such large mown turf surfaces evcn relatively 2o small deviations can mar the overall effect of the pattern.
Additionally, when the patterns become more complex it is often hard for an operator of a mower to determine where exactly he or she is on the pattem. While from a bird's eye view or standing at one end of a field, it is easy to visualize the overall cutting pattem in a field, it is often quite difficult if not impossible for an operator of a mower in the middle of the field to figure out where in the pattern he or she is and where he or she should go frorn any given spot. This problem is exasperated by the fact that that bent blades of grass often do not appear as vivid in the midst of them as they do when standing at a distance. A person standing on a stripe will not be able to see the stripe as easily as a person standing further away. Often the pattern around the mowers is barely visible to the operator of the mower, if he or she is even able to see the pattern at all. This requires an experienced cutter to visualize the "design" or pattern in his or her mind when cutting the grass stnface and to he able to guide the mower based on the memorized design. This is why patterns such as stripes, checkerboard and diamond are the most commonly seen cutting patterns, with pattems involving curvcs and more intricate cuts reserved for special occasions.
SUNLMARY OF THE IIVVENTION
It is an object of the present invention to provide a systent and method that overcomes problems in the prior art.
The present invention comprises a system and method for directing a mower along a cutting path wherein the cutting path will result in a predetermined pattem to be cut into the surface of a field.
A control system is provided that is operative to store a cutting path in its memory.
When the mower follows the cutting path to cut a field, a pattern is cut into the field, such as altemating stripes, checkerboard or diamonds. The mower begins cutting a field at a starting point on the cutting path and as the mower progresses along the cutting path, the control system will repeatedly determine the position of the mower and compare the mower's actual position to the desired cutting path. If the mower has deviated from the cutting path, the control system will transrnit a correction control signal.
The correction control signal will depend on whether the mower has deviated to the right or left of the 1o desired cutting path. If the if the mower has deviated to the right of the desired cutting path the correction control signal will indicate that the mower must be turned left to once again follow the desired cutting path, and vice versa.
In a first embodiment of the invention, the control system is operatively connected to an automatic steering system. When the control system determincs that the mower is deviating from the desired cutting path, the correction control signal is transmitted to the automatic steering system and the mower is automatically steered in the direction necessary for the mower to once again follow the desired cutting path.
In a second embodiment of the invention, the control system is operatively connected to a user display comprising a left indicator light and a right indicator light.
When the control system detcnnines that the mower is deviating frorn the desired cutting path to the iight of the desired cutting path, a correction control signal is transmitted to the user display and the left indicator light is lit to indicate to the user that he or she should manually turn the mower to the left to regain the desired cutting path and vice versa.
As the mower progresses along the cutting path the control system will continue to check the actual position of the mower against the desircd cutting path and when the cutting path has been completed the mower will be fmished mowing the field.
In this manner, the cutting paths can be generated so that by the mower following the cutting path a pattern such as altemating stripes, checkerboard, diamonds or even a more i0 intricate design can be mowed into the surface of the field. Rather than requiring the operator of the mower to attempt to keep the overall design in his or her memory and figuring out what paths to follow with the mower, in the first embodiment of the invention, the mower can be automatically steered by the control system to make the desired pattem or in the second embodiment of the invention, the operator of the mower is simply by directed by the control system how to steer to result in the desired pattern.
The operator does not need to be able to visualize or even plan the design in his or her head. Rather, the design is cut in the surface of a lawn at the direction of the c.~ontrol systern.
2o DESCRIPTION OF THE DRAWINC'S
While the invention is claimed in the concluding portions hereof, preferred embodiments are provided in the accompanying detailed description which may be best understood in conjunction with the accompanying diagrams where like parts in each of the several diagrams are labeled with like numbers, and where:
Fig. 1 is a perspective view of a mower, as is commonly known in the art;
Fig. 2 is a schematic illustration of a conventional hydrostatic drive system;
Fig. 3 is a schematic illustration of an automatic steering system for a mower with a hydrostatic drive, in accordance with a first embodiment of the present invention;
Fig. 4 is a schematic illustration of the automatic steering system of Fig. 3, incorporated into the hydrostatic drive system of Fig. 2;
Fig. 5 is a schematic illustration of a control system in accordance with the present invention;
Fig. 6 is a flowchart of a software process for creating a cutting path for use in guiding a mower along the cutting path to cut a field into a desired pattern;
Fig. 7 is an illustration of a sample of a field map representing a fairway on a golf course for use in the process illustrated in Fig. 6;
Fig. 8A illustrates an altemating stripe pattem;
Fig. 8B illustrates a checkerboard pattem;
Fig. 8C illustrates a diamond pattern;
Fig. 9 is a diagram a cutting path overlaid on a portion of a field map of a fairway wherein following ehe cutting path with a mower will rcsult in a diamond pattern;
Fig. 10 is a schematic illustration of a conventional computer system;
Fig. 11 is a flow chart of a cutting path process for mowing a field in a specified cutting pattern; and Fig. 12 is an illustration of a user display in accordance with a second embodiment of the present invention.
DETAILED DES(.'RIPTION OF THE ILLUSTRATED EMB4DIME'.~1TS
Fig. 1 is a perspective view of a mower that can be used to implement a system and method in accordance with the present invention. Mower 10 is a typical commercial grass mower for cutting the grass on the fairways of golf courses and comprises: a number of cutting reels 12; a left drive wheel 14; a right drive wheel 16;
operator's seat 11; and steering controls 70.
Cutting reels 12 cut the grass to a desired length. The mower 10 is driven by left drive wheel 14 and right drive wheel 16, which are hydrostatically steered and driven by a hydrostatic drive (not shown). An operator sitting in the operator's seat I1 has access to the steering controls 70 and can steer the mower 10.
The Conventional Hydrostatic Steering System of a Commercial Mower Fig. 2 is a schematic illustration of a conventional hydrostatic drive system, such as the hydrostatic drive system that would be incorporated into mower 10, in Fig. 1.
The hydrostatic drive system 50 comprises: a right hydraulic motor 44; a left hydraulic motor 42; a right drive conduit 34; a right return conduit 36; a left drive conduit 32; a left return conduit 37; a valve block 55; a tank 60; a pump 65 and steering controls 70.
In typical operation of the hydrostatic drive system 50, hydraulic fluid from the tank 60 will be pressurized by the pump 65 and the pressurized hydraulic fluid routed to the valve block 55. From the valve block 55, this pressurized hydraulic fluid is routed through the right drive conduit 34 to the right hydraulic motor 44 to drive a right drive wheel 16, as shown in Fig. 1, connected to the right hydraulic motor 44. From the right hydraulic motor 44, the hydraulic fluid is routed back to the routing valve 55 through a right return conduit 36. To drive a left drive wheel 14, as shown in Fig. 1, the pressurized hydraulic fluid is routed through the left drive conduit 32, by the valve block 55, to the left hydraulic motor 42. From the left hydraulic motor 42, the hydraulic fluid is routed back to the routing valve 155 through the left return conduit 37.
An operator controls the mower by entering inputs into the steering controls 70. The steering controls 70 controls the distribution of the flow of the hydraulic fluid by the valve block 55, as commonly known in the art. Based on the operator's steering inputs, the vaive block 55 varies the flow of pressurized fluid to the right wheel hydraulic motor 44 and the left wheel hydraulic motor 42. When an equal flow of hydraulic fluid is provided to the right wheel hydraulic motor 44 and the left wheel hydraulic motor 42, the mower will move in a straight direction of travel. By increasing the flow of pressurized hydraulic fluid to the right wheel hydraulic motor 44, so that more hydraulic fluid is flowing to the right wheel hydraulic motor 44 than the left wheel hydraulic motor 42, the right wheel of the mower is rotated faster than the left wheel causing the mower to tum to the left. Steering the mower to the right is accomplished by increasing the flow of 13 pressurized hydraulic fluid to the left hydraulic motor 42 relative to the right hydraulic motor 44.
Alternatively, the mower can also be tumed by reducing the flow of hydraulic flow to either the right hydraulic motor 44 or the left hydraulic motor 42. For example, the mower can be turned left by left by reducing the aniount of hydraulic fluid flowing to the left wheel hydraulic motor 42 causing the right wheel to rotate faster relative to the left wheel and thereby causing the mower to turn left.
The Auto-steering Components of the Steering System Fig. 3 schematically illustrates an automatic steering system 100 for a mower, in accordance with a first embodiment of the present invention wherein the mower is automatically steered by a control system 300 over part of a cutting path or an entire cutting path by means of control signals received from the control systern 300. The steering system 100 comprises: a left diverting conduit 102, a left tee connection 103; a right diverting conduit 104, a right tee connection 105; a control circuit 110; and a return conduit 120. Generally, although not necessarily, a right flowrate valve 112 and left flowrate valve 114 can also be provided to allow the flowrate of hydraulic flow in the 1o right diverting conduit 104 and left diverting conduit 102 to be adjusted.
Fig. 4 is a schematic illustration of the automatic steering system 100, illustrated in Fig.
3, incorporated into the hydrostatic drive system 50, illustrated in Fig. 2.
The left diverting conduit 102 is operative to contain a flow of hydraulic fluid and is connected into the left drive conduit 32, typically using the left tee connection 103, such that the left divening conduit 102 is operative to divert a portion of a flow of hydraulic fluid out of or away from the left drive conduit 32 so that the portion of the hydraulic fluid that is diverted by the left divert conduit 102 does not drive the left hydraulic motor 42. The right diverting conduit 104 is operative to contain a flow of hydraulic fluid and is connected into the right drive conduit 34, typically using the right tee connection 105, such that the right drive diverting conduit 104 is operative to divert a portion of a flow of hydraulic fluid out of or away from the right drive conduit 34 so that the portion of the hydraulic fluid that is diverted by the right divert conduit 104 does not drive the right hydraulic motor 44.
The control circuit 110 is typically an open center solenoid valve operative to control the flow of hydraulic fluid through the right diverting conduit 104 and the left diverting conduit 102. The control circuit 110, in response a control signal from a control system 300, can open a flowpath and route a flow of hydraulic fluid through either the right diverting conduit 104 or left diverting conduit 102 to the return conduit 120 and back to the tank 60. Although Figs. 2 and 3 show the control circuit 110 as being connected to to both the right divcrting conduit 104 and the left diverting conduit 102, it would be understood by a person skilled in the art that there could be a separate control circuit 110 for each of the right diverting conduit 104 and left diverting conduit 102 and that a single control circuit does not necessarily have to be used to control the flow through both Ihe right diverting conduit 104 and left diverting conduit 102.
The control circuit 110 could comprise one or more valves that simple open or shut a flow path through the control circuit 110 to the return conduit 120 and the control circuit 110 simply routes hydraulic fluid flow through either the right diverting conduit 104 or left diverting conduit 102, for a period of time, to control the steering of the vehicle.
Optionally, if the control circuit 110 simply either stops all flow of hydraulic fluid in the right diverting conduit 104 and the left diverting conduit 102 or opens a fluid flowpath for the right diverting conduit 104 or left diverting conduit 102, the right flowrate valve 112 and left flowrate valve 114 could be used to adjust the flowrate of hydraulic fluid through the right diverting conduit 104 and left diverting conduit 102 when a flow path is opened by the control circuit 110, thereby adjusting the turning rate caused by the steering system 100. The right flowrate valve 112 and left flowrate valve 114 are adjustable flowrate valves that can be adjusted for a set flow rate.
Typically, the right flowrate valve 112 and the left flowrate valve 114 are manually adjustable needle valves allowing the flowrates in the right diverting conduit 104 and the left diverting conduit 102 to be adjusted.
Alternatively, the control circuit 110 could comprise a proportional valve system and the control circuit 110 could be operative to allow varying amounts of fluid flow through the right diverting conduit 104 and the left diverting conduit 102.
The steering system 100 of the present invcntion allows a control systeni 300 to steer a vehicle with a hydrostatic drive, independent of steering inputs from an operator of the vehicle. By inducing hydraulic fluid flow through the right diverting conduit 104, hydraulic fluid flow is diverted away from the right hydraulic motor 44. By reducing the flow of hydraulic fluid to the right hydraulic motor 44, the rotational speed of a right wheel 16, as shown in Fig. 1, being driven by the right hydraulic motor 44 is reduced and the mower wili turn towards the right. Altematively by inducing hydraulic fluid flow through the left diverting conduit 102, hydraulic fluid flow is diverted away from the left hydraulic motor 42, which will in tutn reduce the flow of hydraulic fluid to the left hydraulic motor 42 and cause the mower to turn to the left.
Hydraulic fluid routed through the right diverting conduit 102 or left diverting conduit 104, by the control circuit 110, is passed back through the return line 120 to the hydraulic fluid tank 60 where it can be rcturned to the pump 65 and reused in the hydrostatic drive system 50. Again, although Figs. 2 and 3 illustrate a single control circuit 110 controlling the flow of hydraulic fluid through the right diverting conduit 104 and the left diverting conduit 102, if a separate control circuit was provided for each of the right diverting conduit 104 and left diverting conduit 102, a separate return line connected to each of the right diverting conduit 4 and the left diverting conduit 102 and retuming to the tank 60 could be used, so that the right diverting conduit 104 and the left diverting conduit 102 do not have to be in relatively close physical proximity and connected to a signal eontral circuit 110.
The Control System Fig. 5 illustrates a control system 300 in accordance with the present invention, that is operative to determine when a mower is deviating from a desired cutting path and transmit correction control signals in response to the mower deviating from the desired cutting path. Control system 300 comprises: a processing unit 310, such as a microprocessor; a GPS receiver 320, operative to determine a position based on GPS
signais; a memory 330, for storage of data; and an input/output interface 340.
Generally, althouglt not necessarily the control system 300 can also incorporate a gyroscopic position unit 350 that uses gyroscopes to determine a direction of travel.
While Fig. 5 illustrates a control system 300 that uses a GPS receiver 320 to determine the position of the vehicle, it is contemplated that the control system 300 could use any type of method for dctermining its position such as dead reckoning, beacon referencing, etc.
The control system 300 is operative to compare an actual position of a mower against a desired cutting path stored in the memory 330 of the control system and transmit correction signals from the input/output interface 340 when the mower has deviated from the desired cutting path. As the mowcr is in operation, the control system 300 will repeatedly receive GPS signals using the GPS receiver 320 and determine the position of the mower. The processing unit 310 will compare the determined position of the vehicle -o with the desired cutting path, to determine if the mower is following the cutting path or if the mower has deviated from the cutting path. Additionally, if the control system 300 comprises a gyroscopic position unit 350, the processing unit 310 will be able to determine the direction of travel of the mower and predict whether the direction of travel will cause the mower to leave the desired cutting path.
When the control system 300 determines that the mower has left the desired cutting path, the control system 300 transmits a correction control signal in order to alter the direction of travel of the mower. Upon the processing unit 310 determining that the mower is not on or is leaving the cutting path, the processing unit 310 will determine which way the mower has to be steered to either keep following the desired cutting path or to get the mower back on the cutting path, and the processing unit 310 will send a correction control signal through thc input/output interface 340.
In a first embodiment of the invention, the correction control signal is transmitted to the stecring system 100, of Fig. 3, in order to automatically steer the mower back to the desired cutting path. The correction control signal is transmitted by the control system 300 to the steering system 100 and to the control circuit 110. Depending upon whether the control system 300 determines that the mower is deviating from a desired cutting path in either a right or left direction, the correction control signal transmitted to the control circuit 110 will open a flow path for either the right diverting conduit 102 or left diverting conduit 102, causing the mower to turn to either the left or right respectively.
The correction control signal transmitted from the control system 300 to the control circuit 110 is typically in the form of a voltage input. When the control circuit 110 receives a voltage input from the control system 300, the control circuit opens a flow path and causes hydraulic fluid to flow through either the right diverting conduit 104 or left diverting conduit 102, until the voltage input stops. The control system 300 turns the t5 vehicle to the right by sending a control signal to the control circuit 110 to open a flowpath for the right diverting conduit 104, causing the right diverting conduit 104 to route a portion of the hydraulic fluid flow away from the right hydraulic motor 44 and tums the vehicle to the left by sending a control signal to the control circuit 110 to open a flowpath for the left diverting conduit 102, causing the left diverting conduit 102 to route a portion of the hydraulic fluid flow away from the left hydraulic motor 42.
Whcn the control system comprises a valve system that is either open or shut valves, the rate of tuming can be altered by the sizing of the valve or valves in the valve system.
Using a larger valve or valves will divert more hydraulic fluid flow away from the hydraulic motors causing the vehicle to turn faster when the valves are opened.
Alternatively, the right flowrate valve 112 and left flowrate valve 114 can be uscd to adjust the flowrate in the right diverting conduit 104 and the left diverting conduit 102 thereby altering the flowrate of hydraulic fluid flow way from the hydraulic motor and allowing the turning rate of the steering system 100 to be adjusted.
Altcrnativcly, control circuit 110 can comprise a proportional valve or valves operative to open various amounts in response to control signals from the control system 300. For example, these control signals can be digital signals or analog signals specifying the degree of opening of the valve that is desired, whereby the amount the proportional valve opens will he based on the control signal from the control system 300. In this manner, the control system 300 would also be able to control the flowrate of hydraulic fluid through the right diverting conduit 104 and left diverting conduit 102 and in turn the turning rate of the vehicle. When the vehicle is oi>ly slightly deviating from the desired path, the control system 300 may only open the proportional valve or valves a slight amount to turn the vehicle slowly. Alternatively, if the vehicle is deviating significantly from the desired path, the control system 300 could open the proportional valve or valves a greater amount to cause the rate of turning of the vehicle to be greater.
In a second embodiment of the invention, the correction control signal will be transmitted to a user display 700, illustrated in Fig. 12. The user display 700 comprises a left indicator light 710 and a right indicator light 720. Depending upon whether the control system 300 determines that the mower is deviating from a desired cutting path in either a right or left direction, the correction control signal transmitted to the user display 700 will indicate to an operator which way to steer the mower, by lighting the left indicator light 710 or right indicator light 720, respectively. The user will then steer the mower in the indicated direction.
Referring again to Fig. 5, the control system 300 will continue to detennine the position of the mower in relation to the cutting path as the mower turns and once t.he mower has moved back to the cutting path the control system 300 will stop sending a control signal to to get the mower once again following the cutting path. Typically, a small correction signal operative to turn the mower in the opposit.c direction is required, when the mower is once again on the cutting path, in order to straighten out the mower on the cutting path.
The cutting path stored in memory 330 of the control system 300 determines the path of travel followed by the mower. In the first embodiment of the invention, the mower can be automatically steered, by the control system 300, along relatively straight parts of the cutting path. When a sharp corner is approached, the control system 300 can indicate to a user to turn and an operator then uses the steering controls 70 to change the direction of the mower. Once the mower is once again facing a relatively straight part of the cutting path, the control system 300 resumes automatically steering the mower.
Alternatively, the control system 300 could be given complete control of the mower, with the control system 300 steering the mower along the entire desired cutting path 330, including any relatively sharp turns, with the operator only required to intervene and use the steering controls 70 in the event of an emergency.
Creating a Cutting Path For the mower to mow a pattern into the turf of a field, the cutting path must be created that will result in the desired pattem. Fig. 6 is a flowchart of a software process 400 for creating a cutting path for use in guiding a mower along the cutting path to cut a field into a desired pattern. Process 400 comprises the steps of: starting 405; loading a map of thc field into memory 410; determining a pattern 420; determining the number of mowers t0 430; overlaying cutting path on the field map 440; and finishing 450.
The method starts 405 and a map of the field to be cut is loaded into memory 410. The field map will be a map of the field to be cut in accurate scaled dimensions and displaying any impediments in the field. It can either be selected from a number of pre-existing field maps in memory or it can be created and loaded for the first time. For example, if the field to be cut is a baseball diamond, the field map will show the dimensions of the outfield to scale along with the start of the infield, the pitchers mound, etc. If the field to be cut is a hole of a golf course, the shape of the hole will have the shape fairway to scale and indicate the cart path, any hazards such as sand traps, water hazards, etc., the grcen and any trccs or shrubs that may appear on the fairway.
Fig. 7 illustrates a sample of a field map 460 representing a fair way on a golf course.
Field map 460 will he rendered to scale and will indicate the relative dimensions of the fair way 465, any water hazards 470, sand trap 475, shrubs 480 and the green 490.
Referring again to Fig. 6, the next step will be to determine a cutting pattertt 420. For example, alternating stripes, checkerboard pattem, diamond pattem, etc. could be chosen, as illustrated in Figs. 8A, 8B and 8C, respectively. If these relatively simple designs are chosen, the pattem could be applied to the field in a repetitive manner until the entire field was covered. Alternatively, if the design is a more complex pattern, it may be i o custom designed for a field.
Next, the number of mowers is determined 430. One mower alone can be used to cut the fields. Altematively, more than one mower could be used to achieve the same result quicker. Additionally, one mower may be used for cutting and a second mower may be used without cutting blades, with only a striper toot to bend the grass.
Finally, the ctrtting pattem will be overlaid on the file map 440. A cutting paths to be followed by the mower will be determined using the cutting width of the inower, the dimensions of the field to be cut, the desired pattern to be cut by the mower and the number of mowers to be used. If the pattem selected is a relatively simple pattem such as aiternating lines, checkerboard or diamonds, the pattetn can be repeatedly overlaid on the field map. However, if the design is more complex or non-repeating, it may have to be superimposed on the field map in a large open area and optionally a repetitive pattern used to fill in the edges. If more than one mower is used, the cutting paths will be divided and each mower will be given half of the cutting paths so that both of the mowers cut a complete pattetn when working in conjunction.
Fig. 9 illustrates a cutting path overlaid on a portion of a field map of a fairway wherein following the cutting path with a mower will result in a diamond pattem. The cutting path with make a first cutting path 485 diagonal across the length of the fairway and a second cutting path 490 going diagonal in the other direction across the fairway. By having a mower follow the first cutting path 485 and then the second cutting path 490 a to diamond pattern will be mowed into the fairway. Alternatively, a first mower can be programmed with the first cutting path 485 and a second mower can be programmed with the second cutting path 490. Together the first and second mowers cutting in conjunction will create a diamond pattetn in the mowed fairway.
Referring again to Fig. 6, once the process is completed, a field map of the area to be cut with the cutting paths overlaid on the field map will have been created and the method will finish 450.
In one embodiment of the invention, the software process 400 is run on the control system 300, as shown in Fig. 5. The steps of the process 400 and stored field maps are saved in memory 330 and are implemented by the processing unit 310. A user will make selections for the field map, number of mowers, cutting patterrt, etc. on a display device and interface device (not shown). This embodiment might be particularly useful for such fields as baseball fields or a golf course, where the field maps will not change from time to time or there is a finite number of field maps to choose from, such as an 18 hole golf course and the cutting pattems applied to the ficlds are relatively simple and can be drawn over the existing field maps quite easily.
In an altemative embodiment, the process 400 is implemented on a conventional computer system 500, schematically illustrated in Fig. 10. Conventional computer systcm 500 is suitable for supporting the operation of the process 400 of the present invention. The conventional computer system 500 typically comprises: a processing unit l0 503; a memory storage device 504; an input device 505; a display device 507; and a program module 508.
The processing unit 503 can be any processing unit that is typically known in the art with the capacity to run the program and is operatively connected to the memory storage device 504 such as a local hard-disk, etc. The input device 505 can be any suitable device suitable for inputting data into the computer system 501, such as a keyboard, mouse or data port such as a network connection and is coupled to the processing unit 503 and operative to allow the proccssing unit 503 to receive inforrnation from the input device 505. The display device 507 can be any suitable device coupled to the processing unit 503 and operative for displaying data. The program module 508 is stored in the memory storage device 504 and operative to provide instructions to processing unit 503 to implement the process 400 and the processing unit 503 responsive to the instructions of the program module 508.
Although other intemal components of a computer system 501 are not illustrated, those of ordinary skill in the art will appreciate that many more components and interconnections between them are well known and can be used. As well the computer system 501 need not be limited to only one computer system and may comprise a network of connected computer systems.
By using conventional computer systcm 500, a user would have more flexibility to generate more complex cutting pattetns and apply them to more custonvzed fields, in order to generate a cutting path. Once the cutting path has been generated and stored, it can be saved onto some transportable media and the saved cutting path can be used in control system 300 to have a mower follow the control path.
Directing a Mower to Mow a Pattern into the Turf of a Field Fig. 11 is a flow chart of a cutting path process 600 for mowing a field in a specified cutting pattern. The process 600 comprises: starting 602; loading a cutting path 605;
guiding the mower to a starting point 608; and repeatedly; determining the position of the cutter 610; comparing the position of the mower to the cutting path 620; and transmitting correction control signals to steer the mower if it deviating from the cutting path 640.
The cutting process 600 will start 602 and a cutting path will be loaded 605 into the memory 330 of the control system 300. The cutting path will be a cutting path that has been created using the proccss 400, illustrated in Fig. 6.
Once the cutting path has been loaded 605, a starting point for the control path will be determined and the user will be guided to a starting point 608. The starting point will correspond to a start of a cutting path on the field map.
The operator of the mower will then start the mower moving. As the mower is moving, the control system 300 will guide the mower along the cutting path, by repeatedly determining a position 610, comparing the position to the cutting path 620;
and transmitting correction control signals to steer the mower if it is deviating from its cutting path 640.
For each of these repetitions, the position of the mower is determined 610.
Referring to Fig. 5, the syst.em will repeatedly determine the posilion of the cutter 610.
The processing unit 310 of the control system 300 collects position coordinates for the position of the control system 300 from the GPS receiver 320.
Referting again to Fig. 11, next, the coordinates of the mower will be compared to the cutting path. Referring to Fig. 5, the processing unit 3l0 of the control system 300 compares the coordinates from the GPS receiver 320 to the cutting path stored in the memory 330.
Referring again to Fig. 11, whether or not the mower is on the cutting path will be determined and if the mower is following the cutting path, the method will check to see whether the cutting path is completed 635 and the process will once again dctermine the position of the mower and follow steps 620. 630, etc, if the cutting path has not been completed.
Alternatively, if at 630, it is determined that the mower is no longer on the cutting path, correction signals are transmitted 640 to steer the mower back to the cutting path.
Referring to Fig. 5, when the control system 300 determines that the mower is deviating from the cutting path, the processing unit 310 determines which way the vehicle hat to be steered, based on the position of the mower in relation to the desired cutting path, and the processing unit 310 will send a control signal through the input/output interface 340.
In the first embodiment of the invention, the mower, being used to mow the field, is equipped with the automatic steering system 100, illustrated in Fig. 3, and the control signal transmitted by the control system 300 to the steering system 100 will be transmitted to the control circuit 110 to automatically steer the mower in absence of any input from the operator using the operators controls 70. The control system 300 will determine whether the mower is deviating from the cutting path in either a right or left direction and provide a corresponding control signal to the control circuit 110 to steer the mower back to the cutting path. Based on the control signal, the control circuit 110 will open a flow path for either the right diverting conduit 102 or left diverting conduit 102, causing the mower to turn in the opposite direction back towards the cutting path.
In the second embodiment of the invention, the control signal transmitted through the input/output interface 340 of the control system 300 will be transmitted to a user display 700 as illustrated in Fig. 12 and used to light either a left indicator light 710 or a right indicator light 720. If the control system 300 determines that mower is deviating from the cutting path by drifting to the right of the cutting path, the control signal will activate a left indicator light 710 on the user display 700 to indicate to a user to manually turn the mower to the left to return to the cutting path. If the control system 300 determines that the mower is deviating to the left of the cutting path, the control signal will activate a right indicator light 720 on the user display to indicate to a uscr to manually turn the lo mower to the right to return to the cutting path.
Referring again to Fig. 11, as the mower is moving back to the cutting path, the process 600 will continue to determine the position of the mower 610, compare the coordinates to the cutting path 620 and until the mower is back on the cutting path, the control signal i will continue to be transmitted 640. Once the mower has moved back to the cutting path, when the position of the mower is determined 6l0 and the positioned compared to the cutting path 620, the mower will be determined to be on the path 630 and the control signal will stop being transmitted.
2o As the mower progresses along the cutting path, steps 610, 620, 630, 635 (and when required step 640) will continually be repeated until the mowcr has completed the cutting path, at which time the field will be cut and cutting process 600 will end 650.
Although a system of the present invention can easily be incorporated as original equipment, so that a mower could be manufactured with the control system 300 and, optionally, the steering system 50, outlined herein. Alternatively, the control system could be provided as an aftermarket kit to be added to an existing mower.
The foregoing is considered as illustrativc only of the principles of the invention.
Further, since numerous changes and modifications will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all such suitable changes or modifications in io structure or operation which may be resorted to are intended to fall within the scope of the claimed invention.
Claims
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2588269 CA2588269A1 (en) | 2007-05-09 | 2007-05-09 | Method and apparatus for patterned turf cutting |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA 2588269 CA2588269A1 (en) | 2007-05-09 | 2007-05-09 | Method and apparatus for patterned turf cutting |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2588269A1 true CA2588269A1 (en) | 2008-11-09 |
Family
ID=39971138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2588269 Abandoned CA2588269A1 (en) | 2007-05-09 | 2007-05-09 | Method and apparatus for patterned turf cutting |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA2588269A1 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE2050119A1 (en) * | 2020-02-06 | 2021-08-07 | Husqvarna Ab | Control arrangement, robotic lawnmower, and method of operating robotic lawnmower |
-
2007
- 2007-05-09 CA CA 2588269 patent/CA2588269A1/en not_active Abandoned
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| SE2050119A1 (en) * | 2020-02-06 | 2021-08-07 | Husqvarna Ab | Control arrangement, robotic lawnmower, and method of operating robotic lawnmower |
| SE544518C2 (en) * | 2020-02-06 | 2022-06-28 | Husqvarna Ab | Control arrangement, robotic lawnmower, and method of operating robotic lawnmower |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6907336B2 (en) | Method and system for efficiently traversing an area with a work vehicle | |
| US7010425B2 (en) | Path planner and a method for planning a path of a work vehicle | |
| US8954216B2 (en) | Work machine and components thereof | |
| US5050771A (en) | Repeatable pattern field spraying control | |
| US7953526B2 (en) | Robotic vehicle controller | |
| US5394678A (en) | Electronic control for turf maintenance vehicle | |
| US7343230B2 (en) | Method of operating an automated land maintenance vehicle | |
| US4920733A (en) | Self-propelled, walk-behind, hydraulic motor-operated mower | |
| EP1522823B1 (en) | Modular path planner | |
| US6804597B1 (en) | Automatic guidance system for towed farm implements | |
| US7707810B2 (en) | Apparatus and method to vary the reel speed versus ground speed of an agricultural windrower | |
| BR102018013160B1 (en) | SYSTEM FOR AUTOMATIC SPEED CONTROL, AND METHOD FOR AUTOMATICALLY CONTROLLING THE SPEED OF A WORK VEHICLE | |
| US20080087488A1 (en) | System and Method for Automatic Steering | |
| AU2010201508A1 (en) | Robotic watering unit | |
| US20050015189A1 (en) | Guidance system for towed farm implements | |
| US20210344371A1 (en) | System for optimized use of device with tool driven by a prime mover | |
| CA2588269A1 (en) | Method and apparatus for patterned turf cutting | |
| US20070012462A1 (en) | Golf bunker trimmer with cutter guards | |
| US7331167B1 (en) | Mow/speed interlock system for riding mowers | |
| US11219160B2 (en) | Riding mower with a cutting guide | |
| US7877971B1 (en) | Mower trimmer combination for facilitating simultaneous mowing and edge trimming in a single pass | |
| JP7473360B2 (en) | Automatic control device | |
| JP7387347B2 (en) | Farming support system | |
| WO2016002081A1 (en) | Lawn mower | |
| US20220121202A1 (en) | Power equipment device with driver-assisted semi-autonomous operation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |