Patent Grant
7413380
This application claims priority to and the benefit of U.S. provisional patent application Ser. No. 60/447,169, filed Feb. 12, 2003; U.S. provisional patent application Ser. No. 60/447,218, filed Feb. 12, 2003; U.S. patent application Ser. No. 10/777,466, filed Feb. 12, 2004, now abandoned; U.S. patent application Ser. No. 10/777,491, filed Feb. 12, 2004, now abandoned; U.S. patent application Ser. No. 10/916,187, filed on Aug. 11, 2004, now U.S. Pat. No. 7,012,394; U.S. patent application Ser. No. 10/935,205, filed on Sep. 7, 2004; now U.S. Pat. No. 6,997,642 issued on Feb. 14, 2006; co-pending U.S. patent application Ser. No. 11/331,793, filed on Jan. 12, 2006; and co-pending U.S. patent application Ser. No. 11/400,862, filed on Apr. 10, 2006, each of which applications and/or patents is incorporated herein by reference in its entirety.
The invention relates to turf conditioning systems and method, in general and particularly to an aeration subsystem servicing one or more areas of interest of a golf course having a control module providing intermittent cycles of turf aeration, and/or a simple electronic intermittent control circuit for doing the same to lower operating costs without sacrificing effectiveness.
Prior systems are known for treating soil and turf by blowing and/or sucking air through a perforated duct network located underneath the turf. A high-pressure high-volume air pump or blower unit arrangement is typically used to move air into the soil profile or remove moisture from the soil profile. For example, commonly owned U.S. Pat. Nos. 5,433,759; 5,507,595; 5,542,208; 5,617,670; 5,596,836; and 5,636,473, the disclosure of each of which is incorporated herein by reference, show different versions of equipment used for this purpose. Since an air pump or non-reversing blower discharges air from one connection and pulls in air from another, changing the system from a blowing function to a suction function requires disconnecting the duct network from the pressure outlet of the blower and connecting it to the suction inlet. For this purpose, various valves and/or couplings can be used to avoid the hassles involved with selectively connecting and disconnecting the duct network from the various ports of the blower. Manual operations limit the degree to which the usage can be automated. In addition, considerable judgment is involved in knowing when to blow air into the duct network and when to remove air from the duct network by applying a partial vacuum. For example, blowing air into the duct network when there is too much moisture in the soil profile can severely damage parts of the turf.
Commonly owned U.S. Pat. No. 6,273,638, the disclosure of which is incorporated herein by reference, discloses additional features of an air handling system that includes an air handling device connectable to a duct network that is underneath a grass field, at least one sensor disposed to measure a variable associated with the field, and a control module connected to the air handling device to control operating parameters of the air handling device responsive to an output from the sensor. The variables associated with the field include temperature and moisture. The operating parameters of the air handling device include direction of the air flow, temperature of the air directed into the duct network, and the time of operation of the unit. The system optionally includes programmable control logic so that the sensor output automatically controls the operating parameters of the system. The sensor output can be viewed on the computer display to allow a user to manually control the operating parameters if desired.
The prior turf treatment systems are most commonly known for the ability to remove excess water from the soil profile to improve playability on golf greens and sports fields. For example, a system manufactured by SubAir Systems of Graniteville, S.C., has been featured during major golf tournaments citing its ability to quickly return the greens to firm and fast conditions and for keeping fairways and pedestrian areas free from standing water. This feature minimizes downtime in play and makes the course safer for spectators during times of inclement weather.
Some sports fields, including the soccer field of Manchester United (U.K.), the soccer field of Kilmarnock (U.K.), the baseball and softball fields at the University of Nebraska, and the football field of the Denver Broncos in Denver, Colo., have employed similar methods of operation to those described herein. However, the varied conditions found in golf courses are appreciably different from the conditions found in a single unvarying expanse such as a football, a baseball, a softball or a soccer field, requires novel application of the systems and methods to golf courses.
Not as well known in managing golf course turf are the agronomic benefits that are obtained by introducing fresh air into the soil profile. Fresh air is introduced in the profile whenever excess moisture is removed. Excess moisture and low levels of oxygen are major contributors to turf disease. Turf can suffer even when the level of moisture in the soil profile is not excessive due to poor air quality within the soil profile. There are several reasons for this owing to the fact that plant roots require oxygen for respiration. Through the process of respiration the plant uses up available oxygen located in the pore space between sand particles in the profile and replaces it with carbon dioxide. The deterioration of soil air quality is accelerated when the plant is under stress since the rate of plant respiration increases. Oxygen is also depleted and additional gases are generated as a byproduct of decomposing organic matter within the soil profile due to microbial activity. Microbial activity will vary depending on weather conditions with warm, moist weather being the ideal. Lastly, gases such as methane and hydrogen sulfide may exist in surrounding soil naturally. Because soil air quality can vary independent of soil moisture levels it is beneficial to exchange soil gases on a regular and frequent basis to ensure optimum growing conditions for turf. However, the general industry practice has migrated to turf treatment primarily after rain events. Some golf courses do turf treatments once or twice a week, but this will not achieve optimal results especially when the turf is under stress.
Accordingly, an object of the present invention is to provide an automatic turf conditioning system which can not only remove excess water from golf greens and the like, but can condition the root zone to promote healthy grass as well.
Another object of the invention is to automatically control aeration of a soil profile growing sports turf to increase the oxygen and reduce carbon dioxide in the profile to promote the healthy growth of turf.
The above objectives are accomplished according to the present invention by providing a system and method for conditioning and oxygenating turf of a playing field, such as golf course greens, having a soil profile which includes an aeration subsystem having a plurality of perforated aeration conduits disposed below the turf in fluid communication with the turf. An air blower unit is operatively connected to the aeration conduits for establishing one of a vacuum in a vacuum mode and air under pressure in a pressure mode in the conduits. A control module controls the operation of the blower unit to establish one of the vacuum mode and pressure mode in the aeration conduits in response to sensing an ambient air temperature. Advantageously, the control module operates the blower unit in repetitive cycles of intermittent operation wherein each cycle includes a blower-on mode and a blower-off mode during the one of a vacuum mode and pressure mode. The blower-on mode operates the blower for a first time interval and the blower-off mode discontinues operation of the blower for a second time interval during each of the cycles.
A simplified form of the invention may be advantageously provided when one or more areas are being controlled individually rather than from a central location. In this case, the control module may consist of a simplified intermittent control circuit for automatically controlling the operation of the blower unit. The control circuit may include a repeat cycle timer for operating the blower unit in repeat cycles of intermittent operation. A thermal switch circuit is connected to the cycle timer for operating the blower unit in response to the ambient air temperature in one of a vacuum mode and a pressure mode during the cycles of intermittent operation. The cycle timer operates the blower for a first time interval in the blower-on mode and ceases operation of the blower for a second time internal during each repeat cycle. The intermittent control circuit preferably includes a time delay circuit for delaying operation of the blower unit in a pressure mode to provide ample time for the blower unit to be mechanically reconfigured for pressure mode operation.
The system advantageously includes a first air setpoint and a second air setpoint. The control module initiates the cycles of intermittent operation when the ambient temperature is generally greater than the first air setpoint. The controller module initiates the intermittent operation in the vacuum mode when the ambient air temperature is generally less than the second air setpoint, and initiates operation of the intermittent operation in the pressure mode when the ambient air temperature is generally greater than the second air setpoint. The intermittent operation runs continuously, however, the control module terminates the intermittent operation in response to detecting one of a predetermined environmental condition and operational condition. The environmental condition may include one of a condition of a soil moisture content and an ambient air temperature. The operational condition may include one of an overriding operation of the aeration subsystem selected by an attendant and a scheduled operation event.
In a more fully automated version of the invention, the environmental parameters preferably include ambient air temperature and a soil temperature. There are first and second air setpoints representing prescribed ambient air temperatures, and first and second soil setpoints representing prescribed soil temperatures. The control module controls the blower units in a mode of intermittent operation in response to comparing the ambient air temperature to the first and second air setpoints, and comparing the soil temperature to the first and second soil setpoints. The control module operates the intermittent operation in the vacuum mode when the ambient air temperature is generally greater than the first air setpoint and the soil temperature is generally less than the second soil setpoint. Intermittent operation in the pressure mode is initiated when the ambient air temperature is generally greater than the first air setpoint and the soil temperature is generally greater than the first soil setpoint.
More particularly, the control module initiates the intermittent operation of the aeration subsystem in the vacuum mode when one of the following occurs (1) the ambient temperature is generally greater than the second air setpoint and the soil temperature is generally less that the first soil setpoint, (2) the ambient temperature is generally less than the first air setpoint and the soil temperature is generally greater than the second soil setpoint, (3) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally less than the first soil setpoint, (4) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally greater than the second soil setpoint, and (5) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally greater than the first soil setpoint and generally less than the second soil setpoint.
In regard to the pressure mode, the control module initiates intermittent operation in the pressure mode when one of the following occurs (1) the ambient temperature is generally greater than the second air setpoint and the soil temperature is generally greater than the second soil setpoint, (2) the ambient temperature is generally less than the first air setpoint and the soil temperature is generally greater than the first soil setpoint and generally less than the second soil setpoint, (3) the ambient temperature is generally greater than the second air setpoint and the soil temperature is generally greater than the first soil setpoint and generally less than the second soil setpoint, (4) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally greater than the second soil setpoint.
A computerized method for conditioning and oxygenating turf at an area of interest within a golf course comprises the steps of providing an aeration subsystem at the golf course area which includes a perforated aeration conduit disposed below the turf, a blower unit in fluid communication with the aeration conduit configured to establish one of a vacuum in a vacuum mode and air under pressure in a pressure mode in the aeration conduit, a control module for controlling operation of the aeration subsystem, and a sensor that measures the ambient air temperature. The method determines whether a condition exists for treating the soil at the area in response to the ambient air temperature. If the condition exists, the method operates the aeration subsystem to create one of a vacuum mode and a pressure mode in the aeration conduit for one of reducing or increasing a temperature of turf at the area. Quite advantageously, the method operates the blower units in repetitive cycles of intermittent operation during one of the vacuum mode and pressure mode wherein each cycle includes a blower-on mode and a blower-off mode. The blower-on mode operates the blower units for a first time interval and the blower-off mode discontinues operation of the blower units for a second time interval during each of the repetitive cycles.
The method operates the intermittent operation in the vacuum mode when the ambient air temperature is generally greater than the first air setpoint and the soil temperature is generally less than the second soil setpoint. The method operates the intermittent operation in the pressure mode when the ambient air temperature is generally greater than the first air setpoint and the soil temperature is generally greater than the first soil setpoint.
The construction designed to carry out the invention will hereinafter be described, together with other features thereof.
The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawings forming a part thereof, wherein an example of the invention is shown and wherein:
The systems and methods according to the present invention are useful in managing the operation of aeration subsystems at a plurality of locations, for example areas having different requirements from one another. Different areas on a golf course can have differences in many features, such as in topography, in elevation, in exposure to the sun, and in other features such as water table level, or being subject to wind. For example, a first green is surrounded by a water hazard (for example, a green situated on an island surrounded by water and accessible by a footbridge or golf cart path); a second green is surrounded by sand traps; a third green is exposed to full sun for much or all of a day; and a fourth green is surrounded by trees that shade the green from direct sunlight for a considerable part of the day. Different greens may have different soil conditions and/or different elevations, some may be sloped or terraced; and some may be subject to other unique conditions, such as prevailing winds, or exposure to salt water or salt spray (for example a course situated at the ocean).
Turning to
The green depicted in
Typically, buried in the subsoil of the green is a duct network that is in communication with the lower level gravel bed and serves to carry excess water in the subsoil region away from the green. The duct network includes one or more main feeder lines 15 that are interconnected to a series of distribution lines 16. In the embodiment shown, the lines are arranged in a herringbone pattern that encompasses the green area. In another embodiment, the lines can be arranged as a series of parallel pipes connected along a common border or edge. The lines have openings that permit excess moisture in the soil to be collected in the lines. The lines are laid in the ground so that the collected moisture is gravity fed to the drainage system servicing the golf course. As will be explained in greater detail below, in accordance with the present invention, existing duct network can be retrofitted to the present system to provide underground heating, cooling and other beneficial treatment to the subsoil and turf of the green.
As shown in
In the event the ambient air temperature is relatively high, and the soil temperature surrounding and just below the turf is relatively high, the air will be cooled as it moves through the relatively cooler subsurface soil and gravel beneath the turf thus providing cooling to the turf area or area of interest. If the ambient air temperature is relatively low, and the soil temperature surrounding and just below the turf is relatively low, the air moving through the system will be increased by the relatively warmer subsurface soil thus providing heating to he turf area.
As disclosed in U.S. Pat. No. 5,433,759, a reversing valve unit has a first position when the blower is providing cooling or heated air to the duct network under the turf. Ambient air is delivered to the blower via an inlet line and the blower air discharge is pushed through the heat exchanger and the duct network. Reversing the valve positions causes the blower to draw ambient air downwardly through the green soil profile. When air is being pumped into the duct network, a predetermined volume of air is delivered under pressure through the pipe line into the gravel bed so that the air is distributed uniformly throughout the bed and then driven upwardly to penetrate the entire soil profile. The flow of air through the soil is employed to either heat or cool the turf, depending on the prevailing ambient air and ground conditions. The flow of air through the soil also provides an added benefit in that it serves to aerate the soil and thus promotes the health and growth of the grass turf. When the suction side of the blower is connected with pipe lines in the duct network, a sufficient suction or partial vacuum is provided to draw ambient air downwardly through the soil profile into the gravel distribution bed to again provide the desired heating or cooling of the grass turf. A further benefit of the suction mode of operation is that it affords rapid removal of excess water from the soil profile during periods of heavy rain or flooding. Excess water in the soil is drawn quickly down into the gravel bed and collected in the pipe lines. As disclosed in U.S. Pat. No. 5,507,595, the moisture laden air stream may be drawn into a water separator unit where the moisture and any airborne particulates are removed from the air stream and delivered to a holding tank without interrupting the operation of the blower. The apparatus can, in addition, continuously collect and drain moisture when operating in the pressure or suction mode. Alternatively, the blower operation may be terminated periodically for a short period of time allowing any water collected in the duct lines to be gravity fed to the drain system, where the water can flow away from the green or other area of interest.
As used herein, the term “directive,” as used herein, is intended to mean an instruction from the programmable master control module to a local control module. The term “command” as used herein is intended to mean a computer instruction of a program operating on a computer or an instruction of a control logic sequence of a logic controller, or a user command for the programmable master control module. A user who issues directions of any kind to a local control module directly can be understood to have issued a directive even if the word “command” is used to express the user's action. The term “actionable condition” as used herein is intended to mean that some environmental condition (such as a temperature or a moisture content) is out of tolerance and needs to be corrected by operating the system, but does not imply anything about the condition of the subsurface aeration components. The term “setpoint” as used herein in intended to mean a value set by default, by a computer program, or by an operator to define a desired value of a parameter or condition, or an extremum of a range of acceptable values. An actionable condition occurs when a setpoint is deviated from, or an extreme of a range is exceeded.
Referring now to the drawings, an illustrated embodiment of a golf course turf conditioning control system and method for managing a plurality of golf course areas will now be described in more detail. The system and method of the invention use one or more sensors to provide area information about the state of various environmental variables, such as an ambient air temperature, a soil temperature, and/or a soil moisture content.
Local control modules C of the aeration subsystems receive data from sensors 38 provided for the respective areas of interest. The local control modules may be a PLC, and include a communication link accessible by way of a hand-held battery-powered device selected from one of a cellular telephone, a personal digital assistant (PDA), and a pocket personal computer (pocket PC). The sensors can monitor environmental parameters such as ambient air temperature, soil temperature, soil moisture, soil salinity, air pressure within a conduit, and solar radiation level, as well as other parameters within an area of interest.
In one configuration, the system comprises eighteen (18) aeration subsystems, each one dedicated to a green of a golf course. However, the system can also be used with other portions of a golf course, such as one or more golf greens, one or more fairways, one or more tee boxes, one or more walkways, one or more gallery viewing areas, one or more driving ranges, one or more putting greens, and one or more practice areas.
Master control module B may be configured to receive area information from local control modules C, and to send directives 36 to the local control modules. The programmable master control module may be a programmable computer, a programmable logic controller (PLC), or a programmable industrial controller. The programmable master control module is programmed with software. The software may be a computer program comprised of one or more computer instructions recorded on a machine-readable medium. When the computer program is executing on the master control module, one or more setpoints are defined for the operation of each aeration subsystem. The master control module can compare a setpoint (or a range of acceptable values defined by a first extremum, such as a low air temperature setpoint, and a second extremum, such as a high air temperature setpoint, to an actual value of an environmental parameter observed by a sensor. A single value setpoint can include a tolerance about the setpoint (e.g. X degrees F., plus or minus 0.5 degrees F.). If the actual value of the environmental parameter is within an acceptable range, the programmable master control module can indicate that fact to a user of the system, for example, by displaying on a display the value in green. Master control module B can determine if an actionable condition exists, for example when one or more actual values of environmental parameters fall outside acceptable ranges. If the actual value is outside of an acceptable range, the master control module can indicate that an actionable condition exists, and the fact that caused the actionable condition to a user of the system, for example, by displaying on a display an out-of-range value in red, by displaying the value with a unique font or a unique visual or audible attribute, by for example by flashing the value or emitting a sound. Optionally, the display also indicates the acceptable range for the out-of-range value. In some embodiments, the programmable master control module displays in a defined manner to a user the values of parameters that are being controlled to bring an out-of-range parameter within an acceptable range, for example displaying a value in yellow while the value is out-of-range and the system is taking action to adjust or correct the value. Similar displays are optionally provided at local control modules when a user is operating the respective local control system directly, and/or at a remote location when a user is communicating with the system from such a remote location.
In some instances, a user of the system interacts with local control module C of a specific area of interest in a local mode. For example, when on site, a greens keeper can operate a local control module to perform a necessary operation of the aeration subsystem dedicated to the area of interest. The greens keeper might want to make specific adjustments, perform maintenance, or otherwise personally oversee an operation of the system at that location.
A particular advantageous form of automatic mode operation, according to the present invention, is to operate the system and method continuously but operate in cycles of intermittent operation. The intermittent mode of operation includes continuously repeating cycles wherein the blower unit is turned on for a short interval and turned off for a long interval during each cycle. The level of carbon dioxide decreases significantly after the short interval and retains much of this decrease even during the long interval. At the same time the level of oxygen in the turf increases. The intermittent mode of operation achieves the full benefits of using subsurface aeration from both a moisture removal and agronomic standpoint. In this manner, approximately 50% of the air in the soil profile can be exchanged from a short duration treatment and remain at favorable levels for several hours afterward. By providing this intermittent mode continuously, except for certain manual and programmed overrides, healthy turf at low energy costs can be had. A 5 minute treatment every 2 hours has been found as a preferred cycle of intermittent operation. This duration results in one hour of operation per day per unit. However, to save energy the intermittent mode may be adjusted based on seasonality. So for a golf course with a cool season grass like Bentgrass on its greens, the frequency could be adjusted to 5 minutes per hour during the stressful summer months, 5 minutes every 2 to 3 hours during spring and fall, and 5 minutes every 3 to 4 hours in winter. Although running for just a short duration the aeration subsystem will still draw excess water from the profile.
Intermittent mode operation can be optimized by adding an ambient temperature sensor 38a (
Referring now to the drawings, the intermittent operation of the system will now be described as controlled by control module C. Referring to
Referring now to
Referring now to
The following is an example of first and second air setpoints for controlling the intermittent mode of operation between the vacuum and pressure modes.
Referring to
Referring to
The following is an example of first and second air setpoints and first and second soil setpoints for controlling the intermittent mode of operation between the vacuum and pressure modes.
In another aspect of the invention, a computerized method is provided for conditioning and oxygenating turf at an area of interest within a golf course comprising the steps of providing an aeration subsystem at the golf course area which includes a perforated aeration conduit disposed below the turf, and a blower unit in fluid communication with the aeration conduit configured to establish one of a vacuum in a vacuum mode and air under pressure in a pressure mode in the aeration conduit. A control module controls operation of the aeration subsystem. The method includes determining whether a condition exists for conditioning and oxygenating the soil at the area in response to the ambient air temperature. If the condition exists, the method operates the aeration subsystem to create one of a vacuum mode and a pressure mode in the aeration conduit for one of reducing or increasing a temperature of turf at the area. The method operates the blower units in repetitive cycles of intermittent operation during the one of the vacuum mode and pressure mode wherein each cycle includes a blower-on mode and a blower-off mode. In the blower-on mode, the method operates the blower units for a first time interval, and in the blower-off mode discontinues operation of the blower units for a second time interval during each repetitive cycle. The method terminates the intermittent operation of the aeration subsystem in response to detecting one of a predetermined environmental condition and operational condition. The environmental condition includes one or more of soil moisture, ambient air temperature, and soil temperature. The method includes overriding the cycles of intermittent operation of the aeration subsystem as selected by an attendant or scheduled event.
The method includes a first air setpoint and a second air setpoint programmed in the control module. The method initiates the intermittent operation of the aeration subsystem when the ambient temperature is generally greater than the first air setpoint. The method initiates the intermittent operation in the vacuum mode when the ambient air temperature is generally less than the second air setpoint, and initiates the intermittent operation in the pressure mode when the ambient air temperature is generally greater than the second air setpoint. The method includes environmental parameters of ambient air temperature and a soil temperature. The first and second air setpoints represent prescribed ambient air temperatures, and first and second soil setpoints represent turf soil temperatures. The method operates and blower units in the intermittent operation in response to comparing the ambient air temperature to the first and second air setpoints, and comparing the soil temperature to the first and second soil setpoints. The method operates intermittent operation in the vacuum mode when the ambient air temperature is generally greater than the first air setpoint and the soil temperature is generally less than the second soil setpoint. The method operates the cycles of intermittent operation in the pressure mode when the ambient air temperature is generally greater than the first air setpoint and the soil temperature is generally greater than the first soil setpoint.
More particularly, the method operates the aeration subsystem in the cycles of intermittent operation in the vacuum mode when one of the following occurs (1) the ambient temperature is generally greater than the second air setpoint and the soil temperature is generally less that the first soil setpoint, (2) the ambient temperature is generally less than the first air setpoint and the soil temperature is generally greater than the second soil setpoint, (3) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally less than the first soil setpoint, (4) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally greater than the second soil setpoint, and (5) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally greater than the first soil setpoint and generally less than the second soil setpoint.
In regard to the pressure mode, the method operates the aeration subsystems in the cycles of intermittent operation in the pressure mode when one of the following occurs (1) the ambient temperature is generally greater than the second air setpoint and the soil temperature is generally greater than the second soil setpoint, (2) the ambient temperature is generally less than the first air setpoint and the soil temperature is generally greater than the first soil setpoint and generally less than the second soil setpoint, (3) the ambient temperature is generally greater than the second air setpoint and the soil temperature is generally greater than the first soil setpoint and generally less than the second soil setpoint, (4) the ambient temperature is generally greater than the first air setpoint and generally less than the second air setpoint, and the soil temperature is generally greater than the second soil setpoint.
In the above methods for conditioning the turf of a specific area, the method advantageously may include providing control modules responsive to a directive, and to the ambient air and soil temperatures. The control modules are connected to the aeration subsystems at the areas of interest, and controlling the operation thereof at one or more specific areas. The method may comprise repeating from time to time the determining step, and while the determination is positive, directing the local control modules to operate the aeration subsystems. A programmable master control module is provided in communication with the control modules, and the method receives at the master control module information sent from the control module representing the ambient air temperature and the soil temperature. When the determinative step is positive, the programmable master control module issues a directive to the local control module to operate the aeration subsystem.
As is evident from the disclosure above, systems and methods embodying principles of the invention provide an effective means for treating areas of interest to affect a desired soil temperature changes, oxygenation, and carbon dioxide reduction. At the same time, the systems can be utilized to promote drainage in these regions as well as providing for turf root zone aeration. The systems can be easily retrofitted to existing golf greens or other similar underground drainage systems or incorporated into new construction.
Those of ordinary skill will recognize that many functions of electrical and electronic apparatus can be implemented in hardware (for example, hard-wired logic), in software (for example, logic encoded in a program operating on a general purpose processor), and in firmware (for example, logic encoded in a non-volatile memory that is invoked for operation on a processor as required). The present invention contemplates the substitution of one implementation of hardware, firmware and software for another implementation of the equivalent functionality using a different one of hardware, firmware and software. To the extent that an implementation can be represented mathematically by a transfer function, that is, a specified response is generated at an output terminal for a specific excitation applied to an input terminal of a “black box” exhibiting the transfer function, any implementation of the transfer function, including any combination of hardware, firmware and software implementations of portions or segments of the transfer function, is contemplated herein.
While a preferred embodiment of the invention has been described using specific terms, such description is for illustrative purposes only, and it is to be understood that changes and variations may be made without departing from the spirit or scope of the following claims.
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