Engine speed management control system for cold planers

An engine speed management control system for machines such as cold planers to regulate the idle engine speed as components of the machine are operated to perform functions while the engine is idling. An auto engine speed control routine may determine a combination of active functions of the components being performed and a corresponding idle engine speed to generate sufficient power and pressurized fluid flow to perform the functions. Upon detecting a change in the combination of active functions, the algorithm may change the idle engine speed as dictated by the new combination, or may wait for a specified delay period to determine whether further changes occur to the combination of active functions.

TECHNICAL FIELD

This disclosure relates generally to cold planers and, in particular, to systems and methods for controlling the idle engine speeds of cold planers and other machines to optimize the performance and fuel efficiency of the machines as various components powered by the engine are operated.

BACKGROUND

Cold planers, also known as pavement profilers, road milling machines or roadway planers, are machines designed for scarifying, removing, mixing or reclaiming material from the surface of bituminous or concrete roadways and similar surfaces. Cold planers typically have a plurality of tracks or wheels which adjustably support and horizontally transport the machine along the surface of the road to be planed. Cold planers also have a rotatable planing rotor or cutter that may be mechanically or hydraulically driven to grind up and scrape off the top surface of the road over which the cold planer is driven. As the rotor grinds up the surface of the road, conveyors at the front of the cold planer transport the loose material and dump it into the bed of a truck driving in front of or to the side of the cold planer.

The tracks or wheels and the rotor of the cold planer are driven by an engine of the machine. The cold planer includes additional components and systems that draw power from the engine when operated to perform various functions of the cold planer. Many components function together to regulate the amount of material removed by the rotor, and to contain the removed material and transport the material to the collection vehicle. For example, vertical adjustment of the cold planer with respect to the road surface may be provided by hydraulically adjustable struts or legs that support the cold planer above its tracks or wheels. The legs are extended and retracted to control the depth to which the rotor grinds into the surface. Sideplates disposed on either side of the rotor are raised and lowered to provide a visual depth reference as the cold planer moves across the surface as well as providing lateral enclosure of the rotor and containment of the removed material. The sideplates are typically part of the grade control system and serve as the grade reference used by the control system. A moldboard behind the rotor is positioned at a depth lower than the bottom surfaces of the sideplates to scrape up the loose material and clean the surface so minimal additional cleanup is necessary after the cold planer makes a pass over the surface of the road. An anti-slab in front of the rotor and proximate the first stage conveyor is positioned just above the top surface of the road to break up the material and prevent the rotor from lifting up large chucks of material that are not readily conveyable. A second stage conveyor transports the material up from the first stage conveyor and dumps it into the truck. The second stage conveyor is moved up and down to change its angle and from side to side to properly position the top of the conveyor based on the height and position of the truck. The legs, sideplates, moldboard, anti-slab and conveyors may be driven by hydraulically, with the hydraulics being operated by a common pump that is powered by the engine. Cold planers usually include additional components drawing power from the engine, such as lights, generators and air compressors.

Many of the components of the cold planer may be operated while the cold planer is idling. For example, the positions of the legs, sideplates, moldboard, anti-slab and second stage conveyor may be adjusted before engaging the rotor and making a pass over a surface. Moreover, the rotor may be engaged or disengaged when the engine is idling and not being propelled. The engine speed required to provide adequate pressurized fluid flow for driving the various components to perform the functions of the cold planer varies based on the component being operated, and the combinations of components that are simultaneously being powered by the engine. The lights, generators and air compressors may require minimal power and low engine speeds to operate. In contrast, operating the legs to raise or lower the cold planer simultaneously with repositioning the second stage conveyor may require a greater amount of power via pressurized fluid flow that is supplied by running the engine at a higher engine speed. The operator does not always know the optimum engine speed necessary for performing the functions, and is typically not able to make constant adjustments to the engine speed. The operator may run the engine at a speed that is too low to meet the needs of the operations or, more likely, may run the engine at a higher speed than is required to meet the need such that fuel is wasted and more sound is generated.

In view of this, a need exists for an engine speed management control system for cold planers that is capable of selecting an optimum engine speed for performing the requested operations based on the operations that are being requested, while allowing the operator the ability to override the engine speed to a higher idle where maximum response and cycle times in performing the operations is required.

SUMMARY OF THE DISCLOSURE

In one aspect of the present disclosure, the invention is directed to a machine having an engine, a rotor configured to operatively engage and disengage from the engine, a plurality of components each operatively connected to the engine to receive power from the engine to perform a corresponding function of the machine, a plurality of control switches each corresponding to one of the functions performed by the plurality of components of the machine and configured to provide a control signal according to an actuation status for the corresponding function, and a controller operatively connected to the engine and the plurality of control switches. The controller may be configured to cause the engine to idle at a current idle engine speed corresponding to a current combination of active functions of the plurality of components based on the actuation statuses of the plurality of control switches when the engine is not engaged to propel the machine, and to determine a new combination of active functions of the plurality of components based on the actuation statuses of the plurality of control switches in response to an occurrence of a triggering event. The controller may further be configured to compare the new combination of active functions to the current combination of active functions, and to set the current idle engine speed equal to a new idle engine speed corresponding to the new combination of active functions of the plurality of components and to cause the engine to idle at the new idle engine speed in response to determining that the new combination of active functions is not equal to the current combination of active functions.

In another aspect of the present disclosure, the invention is directed to a method of controlling an idle engine speed of a machine having an engine, a rotor configured to operatively engage and disengage from the engine, a plurality of components of the machine each operatively connected to the engine to receive power from the engine to perform a corresponding function of the machine, and a plurality of control switches each corresponding to one of the functions performed by the plurality of components of the machine and configured to provide a control signal according to an actuation status for the corresponding function. The method may include causing the engine to idle at a current idle engine speed corresponding to a current combination of active functions of the plurality of components based on the actuation statuses of the plurality of control switches when the engine is not engaged to propel the machine, and determining a new combination of active functions of the plurality of components based on the actuation statuses of the plurality of control switches in response to an occurrence of a triggering event. The method may further include comparing the new combination of active functions to the current combination of active functions, and setting the current idle engine speed equal to a new idle engine speed and causing the engine to idle at the new idle engine speed in response to determining that the new combination of active functions is not equal to the current combination of active functions.

Additional aspects of the invention are defined by the claims of this patent.

DETAILED DESCRIPTION

A cold planer10is illustrated inFIG. 1and may include a frame12that is carried for movement along a road surface14by a pair of front track assemblies16and a pair of rear track assemblies18. The frame12is supported on the track assemblies16,18(only two of four track assemblies are shown in the side view ofFIG. 1) by hydraulically actuated adjustable struts or legs20,22, respectively, that extend between each of the pair of track assemblies16,18and the frame12. Hydraulic cylinders (not shown) are used to extend and retract the legs20,22to raise and lower the cold planer10.

A rotor24may be rotatably mounted to the frame12and may have a housing26surrounding all but the body of the rotor24, which is necessarily exposed to the road surface14. The depth of the cut or penetration of the cutting teeth (not shown) of the rotor24is controlled by appropriate extension or retraction of the adjustable legs20,22and corresponding cylinders. The cold planer10also includes an engine30as a source of power that may drive the rotor24via a mechanical drive arrangement that may include pulleys32,34, a belt36and a belt tensioner38. Of course, as will be apparent to those skilled in the art, other arrangements can be employed besides the mechanical arrangement shown inFIG. 1, such as a gear train, hydraulic system or other mechanism for transforming rotation of the engine into rotation of the rotor24.

The housing26may be made up of several components that assist in containing and removing the material of the road surface14that is ground up by the rotor24, with each of the components being vertically positionable to account for the depth to which the rotor24will dig into the road surface14. Sideplates40(only one shown in side view ofFIG. 1) may be disposed on either side of the rotor24and may be raised and lowered to provide a visual depth reference as the cold planer10moves across the road surface14as well as to provide lateral enclosure of the rotor24and containment of the removed material. A moldboard (not shown) may be disposed behind the rotor24and positioned at a depth lower than the bottom surfaces of the sideplates40to scrape up loose material and clean the road surface14so minimal additional cleanup is necessary after the cold planer10makes a pass over the road surface14. An anti-slab (not shown) disposed in front of the rotor24may be positioned just above the top of the road surface14to break up the material and prevent the rotor24from lifting up large chucks of material that are not readily conveyable. The cold planer10may also include a first stage or pickup conveyor42which delivers debris to a second stage or discharge conveyor44. The discharge conveyor44and its associated framing and pulleys (not shown) may be supported by a telescoping arm46, both of which are only partially shown inFIG. 1. Finally, the cold planer10may also includes an operator area48having a control console50with the necessary instruments to allow an operator to control the operation of the various components of the cold planer10.

A control console50is partially illustrated inFIG. 2which schematically illustrates the relationship between a controller or ECM52of the cold planer10and the remaining components relevant to the systems and methods described in the present disclosure. Of course, the control console50may also include gauges for water pumps, compressors and other components, status indicators, additional switches and the like, that are omitted from the illustration and discussion for the sake of clarity on the disclosure. As illustrated inFIG. 2, the controller52may include a memory54, and may also include a clock or timer56. The controller52may be linked to the engine30, and to a first clutch58that may be a hydraulically actuated clutch58that is coupled to the engine30. The first clutch58may also be detachably engaged to the rotor24, which may also be linked to the controller52.

The cold planer10may further include at least one pump60that may be linked to the controller52for providing pressurized fluid flow to the hydraulic elements that cause the movements of various components of the cold planer10. The pump60may be coupled to the engine30by a second clutch62that may also be linked to the controller52. The controller52may be capable of actuating and de-actuating the second clutch62to alternately couple and decouple the engine30and the pump60. In the illustrated embodiment, the pump60may be coupled to multiple components of the cold planer10and provide hydraulic fluid to the various hydraulic elements as commanded by the controller52. For example, the pump60may provide pressurize fluid flow to the hydraulic elements of the legs20,22, the sideplates40, the moldboard64, the anti-slab66, the pickup and discharge conveyor drives68,70, respectively, and the discharge conveyor vertical and yaw angle controllers72,74, respectively. Control signals from the controller52may cause the pump60to direct fluid flow to the appropriate hydraulic elements as commanded by the operator.

The engine30may provide power to additional elements of the cold planer10that may be turned on and off based on the operator's needs. For example, a generator76, an air compressor80and lights84may be linked to the controller52and electrical system of the cold planer10that is powered by the engine30when running. Those skilled in the art will understand that additional components controlled by the operator of the cold planer10and drawing power from the engine may be present in the cold planer10.

Still referring toFIG. 2, the control console50may include a variety of operator inputs to control the operation of the various components of the cold planer10. ON/OFF switches86,88,90for the lights84, generator76and air compressor80, respectively, may cause the controller52to turn the components on and off as necessary. In the cases of the generator76and air compressor80, setting the switches88,90to the “ON” positions may cause the controller52to actuate the generator76and air compressor80and thereby draw power from the engine30. Vertical adjustment switches92,94,96,98may toggle between “UP” and “DOWN” positions to control height adjustment for the legs20,22, sideplates40, moldboard64and anti-slab66, respectively. When one of the vertical adjustment switches92,94,96,98is actuated in either setting, the controller52may cause the second clutch62to engage the engine30to transmit power to the pump60if the second clutch62is not already engaged, and cause the pump60to provide pressurized fluid flow to hydraulic elements of the components20,22,40,64,66corresponding to the actuated switches92,94,96,98to raise or lower the components.

ON/OFF switches100,102may also be provided for the pickup and discharge conveyor drives68,70, respectively. Setting the switches100,102to the “ON” positions may cause the controller52to signal the second clutch62to engage the engine30if the second clutch62is not already engaged to transmit power to the pump60, and cause the pump60to provide pressurized fluid flow to the conveyor drives68,70. If the speeds of the conveyors42,44are controllable by the operator, the ON/OFF switches100,102may be replaced or supplemented on the control console50by dials, potentiometers or other control mechanism capable of providing a variable signal to the controller52indicative of speeds at which the conveyors42,44are to operate, and the controller52may be programmed to transmit corresponding signals to the pump60to control the fluid flow transmitted to the conveyor drives68,70. Additional switches104,106may be provide for adjustment of the vertical angle and yaw angle, respectively, of the discharge conveyor44by sending signals to the controller52to cause the pump60and second clutch62to provide fluid flow to the vertical angle controller72and yaw angle controller74for moving the discharge conveyor44to a desired position.

Controls for additional functionality of the cold planer10may also be provided at the control console50. An engine speed control switch108may be provided to allow the operator to select between engine speed control modes that are available for operation of the cold planer10. The operator may be provided with the ability to cycle between an auto engine speed control mode discussed in further detail below, and a high idle engine speed mode. The engine speed control switch108may allow the operator to cycle between the modes. Setting the engine speed control switch108in the “AUTO” mode position may cause the controller52to control the speed of the engine30according to the strategy detailed hereinafter, while the “HIGH IDLE” setting may cause the controller52to cause the engine30to idle at a predetermined speed that may be greater than an engine speed that may be determined by the auto engine speed control.

The controller52of the cold planer10may also be programmed with a service mode that also allows the operator to override the auto engine speed control routine to operate the engine30at a desired engine speed. The service mode may be available to the operator for instances where the operator wants the engine30to run at a specific engine speed. The service mode may provide the operator with the ability to manually adjust the engine speed to a desired setting for troubleshooting problems with the cold planer10. The service mode may be available through a machine display110on the control console50. The operator may navigate into the service mode screen via the machine display110if provided as a touch screen, via the engine speed control switch108if provided as an additional control option, or through additional controls that may be provided on the control console50.

Once in the service mode, the operator may select a desired engine speed from a range of engine speeds that may be selectable on the machine display110. For example, the engine speed may be selectable from a range having a minimum speed of 800 RPM, a maximum speed of 1,900 RPM, and discrete intervals of 50 RPM there between. When in the service mode, certain functions of the cold planer10may be partially locked out by the controller52. The operator may not be able to engage the rotor24or propel the cold planer10forward or backward. Also, the cold planer10may be configured to prevent the operator from entering the service mode if any of the functions that are locked out when the cold planer10is in the service mode are currently active. Once the operator has completed troubleshooting the cold planer10, the operator may exit the service mode through the machine display110or other mode control switches.

When the cold planer10is running but idling, and the various components drawing power from the engine30are actuated by the operator, the engine speed must increase to meet the power and pressurized fluid flow needs of the components. The operator may not know the engine speed necessary to satisfy the power needs of the components, and may instinctively increase the engine speed, but may run the engine30at a higher speed than that required to power the components. Running the engine30at a higher speed than necessary wastes fuel and unnecessarily increases the sound produced by the cold planar10. The difficulty of operation of the cold planer10is increased for the operator who attempts to run the engine30closer to the minimum required speed to power the components. In order to minimize fuel consumption by the cold planer10, reduce average sound levels and enhance ease of operation of the cold planer10for the operator, the speed of the engine30when idling may be automatically adjusted by the controller52based on the machine commands that are transmitted from the control console50to the controller52for the operation of the various components of the cold planer10.

In one implementation of the cold planer10, the controller52may be provide with a look-up table stored in memory or programmed into the control application program that may specify a speed at which to operate the engine30based on the operation or combination of operations being commanded by the operate when the cold planer10is idling.FIG. 3illustrates an example of a table120containing information regarding the engine speeds at which the controller52may cause the engine30to idle when certain operations are commanded at the control console50. As illustrated in the table120, the various operations and components of the cold planer10may require varying levels of power from the engine30to operate. To accommodate the power needs, the engine30may be caused to idle at engine speeds corresponding to the power needs of the commanded operations. For example, during initial start-up or where no operations are being commanded by the operator, the controller52may cause the engine to idle at a relatively low engine speed, such as 800 RPM.

When the various components are commanded to operate by the operator at the control console50, the controller52may respond by causing the engine30to operate at the engine speed specified in the table120. Different components draw different amounts of power from the engine30and, consequently, different engine speeds are required to meet the power needs. Components such as the lights84, generator76and air compressor80may require a relatively small amount of additional power to operate. Consequently, when one of the switches86,88,90is set to the “ON” position, the controller52may respond by increasing the engine speed to 1000 RPM. The components having hydraulic elements driven by the pump60may require a greater amount of power from the engine30and fluid flow from the pump60during their operation. As a result, the controller52may engage the second clutch62to drive the pump60and increase the engine speed to 1300 RPM for the pump to drive the hydraulic elements of the commended component.

During the course of operating the cold planer10, multiple operations may be commanded at the same time. The table120may be configured to cause the engine30to run at an engine speed that will meet the power requirements for the various commanded operations. Some combinations of operations may only require the engine30to operate at the engine speed required for the operation requiring the most power. In such cases, the engine speed may be set to the highest value in the table120corresponding to one of the commanded operations. For example, where the operator sets the switches90,100to the “ON” positions to actuation the air compressor80and pickup conveyor drive68, respectively, the controller52may cause the engine30to operate at 1,300 RPM, which may provide sufficient power for both operations.

Other combinations of operations may require the engine30to be operated at a greater speed than is required for either of the individual operations. For example, where multiple components or systems receiving pressurized fluid from a common pump are commanded at the same time, the engine speed may be further elevated to ensure adequate system performance and sufficient fluid provided to the hydraulic elements of the components. The specific amount of engine speed elevation will depend on the combination of functions being commanded. Per the exemplary table120, where two operations driven off the same pump are commanded, the controller52may cause the engine30to operate at 1,600 RPM. This may be the case where, for example, the operator uses the switches94,96to adjust the positions of the sideplates40and moldboard64, respectively, up or down. Operations having higher flow demands from the pump60may correspondingly require a greater engine speed. As discussed above, the conveyor drives68,70may have variable speeds of operation, and the higher speeds may require greater flow from the pump60. The required flow may be provided by the controller52causing the engine30to further increase the engine speed to 1,900 RPM. Greater flow may also be necessary when more than two operations running of the same pump are commanded, and the table120may be configured to provide the necessary engine speed to meet the power and fluid flow demands. Those skilled in the art will understand that the engine speed ranges set forth in the table120are exemplary only, and the engine speed requirements for particular cold planers10and their components and operations will vary based their designs. Such variations are contemplated by the inventors as having use in cold planers10in accordance with the present disclosure.

FIG. 4illustrates an exemplary auto engine speed control routine130for controlling the idling speed of the engine30of the cold planer10or other type of machines or equipment that may perform operations drawing power from the engine30while the engine30is idling. The execution of the engine speed control routine130presumes that the engine speed control switch108is set to the “AUTO” position for automatically controlling the engine idling speed, and that the operator has not navigated into the service mode to control the engine speed via the machine display110. The engine speed control routine130may be begin at block132wherein the engine30may be started up by an operator. When the engine30is started, control may pass to a block134where the controller52may set the engine speed to a low idle speed at which the engine30may initially operate, and may subsequently operate when idling with no functions being active or commanded. The low idle speed may be provided by the data of the table120as stored in the memory54or programmed into the control software implementing the table120. Once the engine speed is set, the engine30will operate at the low idle speed, such as 800 RPM as specified in the exemplary table120, until a function is commanded by the operator, the rotor24or drive mechanism for the cold planer10is engaged, or the engine30is shut off.

As the engine30of the cold planer10continues to idle, control may pass to a block136wherein the controller52monitors the switches86-106for actuation by the operator to command a function of the cold planer10. The controller52may check for actuation of the switches86-106by an operator at a sampling rate provided by the clock56. After each monitoring period, control may pass to a block138wherein the controller52may determine whether a status of any of the switches86-106has changed since the previous monitoring period. If the statuses of the switches86-106are unchanged, control may pass back to the block136for further monitoring for actuation of the switches86-106.

If the controller52determines that the status one or more of the switches86-106has changed (e.g., changed from “OFF” to “ON” or “ON” to “OFF,” or toggled to “UP” or “DOWN,” “LEFT” or “RIGHT,” or back to the neutral position) at the block138, control may pass to a block140wherein the controller52may determine the engine speed corresponding to the combination of commanded functions indicated by the statuses of the switches86-106. At block138, the controller52may refer to the engine speed table120to determine the appropriate engine speed to provide sufficient power for the functions commanded by the operator via the switches86-106. As discussed above, the controller52may be programmed with the necessary logic for converting the input provided by the switches86-106into the engine speeds listed in the table120. Such logic may include a simple table lookup in a database stored at the memory54, hard coded logic wherein each combination of actuated switches86-106outputs a predetermined engine speed, or combination thereof or other programming methods performing the necessary conversion of inputs into output speeds.

After the controller52determines the new engine speed at the block140, control may pass to block142where the controller52compares the new engine speed to the current engine speed to determine whether the engine speed is decreasing from the current engine speed setting. If the new engine speed is greater than or equal to the current engine speed, the engine speed change may be executed without delay. Control may pass to a block144wherein the controller52may set the engine speed to the new engine speed determined based on the engine speed table120. Once the engine speed is set and the engine speed increases, control may pass back to the block136where the controller52may continue to monitor the statuses of the switches86-106on the control console50. At the same time, the controller52will cause the commanded functions to be performed.

If the new engine speed is determined to be less than the current engine speed at block142, and the engine will be slowed, it may be desirable to delay slowing the engine to prevent a sudden slowing of the engine followed by an immediate speeding of the engine that may cause additional stress on the engine30and fuel usage. Instead, it may be preferable to wait for a specified period of time before slowing the engine30to determine whether any additional function commands are input at the control console50. As a result, where the new engine speed is less than the current engine speed at block142, control may pass to a block146wherein the controller52may utilize the clock56to delay for a predetermined delay period, such as, for example, three seconds, within which the operator may command additional functions or discontinue functions. It should be noted that the delay period may not cause a corresponding delay in the execution of the requested machine functions.

After the delay period elapses, control may pass to a block148wherein the controller52monitors the statuses of the switches86-106to determine the combination of functions commanded by the operator in a similar manner as the monitoring performed at block136. After determining the statuses of the switches86-106and the corresponding combination of requested functions at block148, control may pass to a block150wherein the controller52may determine whether the combination of commanded functions has changed again. If the combination of commanded functions is unchanged, control may pass to the block144for the controller52to set the engine speed to the new engine speed determined at block140so that the engine speed is reduced to the lowest engine speed necessary to support the commanded functions as determined from the engine speed table120. Once the engine speed is set and the engine speed decreases, control may pass back to the block136for continued monitoring of the statuses of the switches86-106on the control console50by the controller52. If the combination of commanded functions is determined at block150to have changed during the delay period, control may pass to the block140for the controller52to determine the appropriate engine speed for the new combination of commanded functions.

In an alternative implementation of the cold planer10, the machine functions performed by the various components of the cold planer10may be assigned values based on the hydraulic flow demand placed on the engine30when the components are operated to perform the machine functions. The engine power demand values for the active machine functions may be totaled and used by the controller52to determine the idle speed of the engine30needed to provide sufficient power for performing the active machine functions.FIG. 5illustrates an example of a machine function demand table160containing information regarding the machine functions that may be performed by the components of the cold planer10, the active function states of the components, and an engine power demand value for each machine function. For example, the front legs22may have function states of raising and lowering the cold planer10as commanded by the actuation statuses of the switch92, and those function states may require an engine power demand having a value of “3.” The rear legs20may have similar function states and be independently controlled by a separate control switch (not shown), but may require a greater engine power demand having a value of “4.” The other machine functions discussed above as well as additional machine functions may each be similarly assigned engine power demand values, and those skilled in the art will understand that additional control switches or other actuation means for activating the machine functions may be provide in the operator area48as necessary.

The controller52may continually monitor the operational statuses of the various machine functions, such as by evaluating the actuation statuses of the control switches86-106. As the combination of active functions of the components changes, the controller52may calculate an active functions total of the engine power demand values from table160for the active machine functions to determine the total engine power demand at a point in time. The total engine power demand as indicated by the active functions total may dictate the required idle engine speed for the active machine functions to be performed.FIG. 6illustrates an alternative configuration of an engine speed lookup table162that may be stored by the controller52. The illustrated table162summarizes the idle engine speeds corresponding to the various active functions totals. As the combination of active machine functions changes and, correspondingly, the active functions total changes, the idle engine speed may increase and decrease over time, and the controller52may adjust the speed of the engine30accordingly.

FIG. 7illustrates an exemplary auto engine speed control routine170for controlling the idle engine speed of the engine30of the cold planer10or other type of machines or equipment using the information in the machine function demand table160and the engine speed lookup table162when the control switch108is set to the “AUTO” position. The engine speed control routine170may be begin at block172wherein the engine30may be started up by an operator. When the engine30is started, control may pass to a block174where the controller52may set a current active functions total equal to zero so the engine30may initially idle at a low idle engine speed before the operator starts activating machine functions. Consequently, at a block176, the controller52may set the engine30to idle at an idle engine speed based on the value of the current active functions total.

As the engine30of the cold planer10continues to idle, control may pass to a block178wherein the controller52monitors the switches86-106for actuation by the operator to command a function of the cold planer10. The controller52may check for actuation of the switches86-106by an operator at a sampling rate provided by the clock56, or may continuously monitor the activation statuses of the switches86-106and detect a change in activation status of one or more of the switches86-106. On the occurrence of a triggering event such as the elapsing of the sampling period or detection of an activation status change, control may pass to a block180wherein the controller52may calculate a new active functions total by summing the engine power demand values from the table160for the new combination of active machine functions.

The new active functions total may or may not require a change in the idle engine speed. As with the routine130, the routine170may allow the idle engine speed to increase immediately if necessary when there is a new combination of active functions, but wait for a prescribed delay period when the engine power demand decreases to determine whether other machine functions are activated and would necessitate and idle engine speed increase. After calculating the new active functions total, control may pass to a block182to compare the new active functions total to the current active functions total. If the new active functions total is not less than the current active functions total, the idle engine speed may remain the same or increase. In this situation, control may pass to a block184to set the current active functions total equal to the new active functions total, and then to the block176to set the idle engine speed based on the new value of the current active functions total.

If the new active functions total is less than the current active functions total at the block182, it may ultimately be necessary to decrease the idle engine speed if no other changes are made to the combination of active functions. In this situation, control may pass from the block182to the block186wherein the controller52may utilize the clock56to delay for a predetermined delay period, such as, for example, three seconds, within which the operator may activate additional functions or discontinue functions. It should be noted that the delay period may not cause a corresponding delay in the execution of the requested machine functions.

After the delay period elapses, control may pass to a block188may calculate a delay active functions total by summing the engine power demand values from the table160for the combination of active machine functions at the end of the delay period. After calculating the delay active functions total, control may pass to a block190wherein the controller52may determine whether the delay active functions total is less than the new active functions total that was calculated before the delay period. If the delay active functions total is not less than the new active functions total, the post-delay combination of active functions has the same engine power demand and requires the same idle engine speed, or an increase in the engine power demand and corresponding increase in the idle engine speed. In this situation, control may pass to a block192to set the current active functions total equal to the delay active functions total, and then to the block176to set the idle engine speed based on the new value of the current active functions total.

If the current active functions total is less than the new active functions total at the block190, it may be desired to wait for additional changes to the combination of active functions before decreasing the idle engine speed. Consequently, control may pass from the block190to a block194wherein the controller52may set the new active functions total equal to the delay active functions total, and then to the block186to initiate a second delay period and to the block188to calculate a second delay active functions total for the combination of active functions after the second delay period. The second delay active functions total is then compared to the new active functions total at the block190to determine whether to reset the idle engine speed or to continue waiting for additional delay periods until the combination of active functions and corresponding active functions total stop decreasing.

The engine speed control routines130,170as described above may be executed by the controller52during periods when the cold planer10is running but is not being propelled forward. In other operational states of the cold planer10, the blocks of the engine speed control routines130,170may be modified or overridden in their entirety based on the engine speed control requirements for the cold planer10. In the service mode as described above, the operator via the machine display110may operate the engine30at a specified speed for troubleshooting problems with the cold planer10. As another example, when the cold planer10is in a static or non-propelled state with the rotor24engaged, the auto engine speed control routines130,170may be active but modified to reflect the minimum engine speed requirements for the engaged rotor24. The engine speeds specified in the tables120,162may be overridden to the extent they are lower than the minimum speed for the engaged rotor24. The minimum idle engine speed for the engaged rotor24may be, for example, 1,150 RPM, and the controller52may only modify the engine speed if the engine speed required for the commanded combination of active functions per tables120,170is greater than what is necessary for the rotor24. Where no operations are commanded, or only a combination with a relative low engine power demand for idling are commanded, the controller52may set the engine speed to 1,150 RPM at blocks134,144, or176. If operation of a sufficiently high engine power demand combination of active functions is commanded, the controller52may set the engine speed to an appropriate idle engine speed above 1,150 RPM. When sufficient active functions are turned off by the operator to reduce the engine power demand, the controller52reduces the engine speed back down to the low idle speed of 1,150 RPM for the rotor24after the specified delay period.

When the rotor is engaged and the engine30is engaged to propel the cold planer10forward, the auto engine speed control routines130,170may be disabled. The engine speed may remain at the milling rotor speed requested by the operator at controls provided in the operator area48, such as 1,600, 1,750 or 1,900 RPM. When the cold planer10is stopped and the engine30is disengaged from the rotor, the engine speed control routines130,170may be re-enabled for the controller52to resume control of the idle engine speed of the engine30.

The operator or a technician may have the capability to override the auto engine speed control routines130,170to dictate engine speeds necessary for performing certain operations or testing of the cold planer10. The operator or technician may have the ability to cycle between the auto engine speed control routines130,170and a forcing a high idle engine speed, such as 1,900 RPM. The operator may cycle between the control mode and high idle mode via the engine speed control switch108at the control console50. Toggling the engine speed control switch108to the “HIGH IDLE” position may cause the controller52to operate the engine30at the predetermined high idle engine speed. Toggling the engine speed control switch108back to the “AUTO” position may re-enable execution of the engine speed control routines130,170by the controller52. When the rotor24is engaged, the ability to cycle between the manual and auto engine speed control modes may be disabled, and the engine speed may be dictated by either the desired rotor milling speed set by the operator as discussed above, or by the engine speed control routines130,170if a specific engine speed is not commanded by the operator.

INDUSTRIAL APPLICABILITY

In operation, the auto engine speed control routines130,170control the idle speed of the engine30of the cold planer10. At the beginning of a planing job, an operator may start the engine30of the cold planer10. Using the routine130in the following example, if the engine speed control switch108is sent to “AUTO,” the controller52may set the engine30to idle at 800 RPM per the engine speed table120at block134. If the job is being started first thing in the morning, the operator may set the light switch86to the “ON” position to turn on the lights84. The controller52may detect the change in status of the light switch86at block138, and determined that the engine speed should be increased to 1000 RPM140. Because the engine speed is increasing, the controller52may set the engine30to the new engine speed at block144without waiting for a delay period.

Once the cold planer10is started and idling, the operator may position the rotor24and housing26in preparation for making the initial pass over the road surface14. The operator may set the height of the rotor24via the legs20,22. Assuming the rotor24is elevated above the road surface14, the operator may press the height adjustment switch92to the “DOWN” position to lower the rotor24into position. The controller52may detect the actuation of the height adjustment switch92at block136, and transmit control signals to the clutch is62to engage and to the pump60to control the flow of hydraulic fluid to the actuators for the legs20,22to lower the cold planer10. The controller also determines that the combination of the lights84and the movement of the legs20,22dictates an engine speed of 1,300 RPM at block140and since the engine speed to the elevated idle speed at block144.

When the rotor24is in position, the operator may release the height adjustment switch92allow the switch92to move to its neutral position. The status change of the switch92may be detected by the controller52at the block138, and the controller52missing control signals to the pump60to discontinue actuation of the legs20,22. The controller52may determine that the engine speed is to be reduced to 1,000 RPM at block140. The engine speed reduction causes the controller52to transfer control from the block142to the block146for the clock56to countdown the predetermined delay period, such as 3 seconds, to determine whether other functions are commanded by the operator. During the delay period, the engine speed is maintained at 1,300 RPM.

With the rotor24in position, the operator may actuate the sideplate adjustment switch94and the moldboard adjustment switch96to begin the adjustment of the housing26by positioning the sideplates40and the moldboard64. The controller52may detect the actuation of the switches and94,96at block148,150, and transfer control back to the block140to determine the new engine speed. At the same time, the controller52may send control signals to the pump60to supply hydraulic fluid to the actuators for the sideplates40and moldboard64. The controller52may determine at the block140that the idle engine speed should be 1,600 RPM for performing two operations on the same pump60, and may set the engine30to idle at the new engine speed at block144.

After the sideplates40and the moldboard64are in position, the operator may release the switches94,96to allow them to return to their positions, and actuate the height adjustment switch98to position the anti-slab66. The controller52may detect the change in status of the switches94,96,98at the block136and determined that the appropriate engine speed for operating the anti-slab66as 1,300 RPM at the block140. The controller52may command the pump60to cease flow of hydraulic fluid to the actuators for the sideplates40and the moldboard64, and to begin pumping hydraulic fluid to the actuator for the anti-slab66, but may delay decreasing the engine speed during the delay period of the block146. After the delay period elapses with the height adjustment switch98still actuated, the controller52may set the new engine speed at the block144to slow the engine30to the specified stream. When the anti-slab66is in position, the operator may release the height adjustment switch98. The controller52may detect the status change of the height adjustment switch98at the block136and determined that the engine speed should be decreased to 1,000 RPM at the block140because the lights84are still turned on. The controller52may send control signals to the pump60to cease the flow of hydraulic fluid to the actuator for the anti-slab66and, after waiting for the delay period to elapse at block146and not detecting further changes in the status is of the switches86-106, reduce the engine speed to 1,000 RPM at block144.

With the rotor24and the housing26positioned, the operator may use the appropriate controls in the operator area48to engage the rotor24. The controller52may detect the engagement of the rotor24and may set the low idle speed for the engine30to the engine speed specified for rotor engagement, such as 1,150 RPM. Prior to propelling the cold planer10forward, the operator may turn on the conveyors42,44by setting the switches100,102to their “ON” positions. The controller52may detect the actuation of the switches100,102at the block136. The conveyors42,44may have a high flow demand from the pump60, and consequently the controller52may determine at the block140that the idle engine speed should be set to 1,900 RPM, and may set the engine30to idle at that speed at the block144. At this point, the operator may engage the transmission of the cold planer10to propel the cold planer10forward for its initial pass over road surface14. Engagement of the transmission may cause the controller52to disable the auto engine speed control routine130.

At the end of the job, after the final pass of the cold planer10over the road surface14, the operator may disengage the transmission to stop the cold planer10. The controller52may detect the disengagement of the transmission and re-enable the auto engine speed control routine130to control the idle speed of the engine30. With the rotor24remaining engaged and the conveyors42,44running, the controller52may determine that the appropriate engine speed is 1,900 RPM based on the engine speed table120at the block140, and set the engine speed to the new idle speed at the block144. After the cold planer10stops, the operator may disengage the rotor24and turn off the conveyors42,44by setting the switches100,102to their “OFF” positions. The controller52transmits control signals to the first clutch58to cause the clutch to disengage from the engine30. The change in the statuses of the switches100,102may be detected by the controller52at the block136and, combined with the disengagement of the rotor24, the controller52may determine at the block140that the appropriate speed for the engine30is 1,000 RPM because the lights84are on but the rotor24is disengaged, and the engine30no longer requires the elevated low idle speed of 1,150 RPM.

The controller52may stop the conveyors42,44during the delay period of the block146by transmitting control signals to the pump60to cease providing hydraulic fluid to the actuators of the conveyors42,44. The controller may also send control signals to the second clutch62to disengage from the engine30since no functions are being commanded that require the pump60to operate. If the operator turns the lights84off by setting the light switch86to the “OFF” position during the delay period, the controller52may turn off the lights84and send control of the engine speed control routine130back to the block140from the blocks148,150where the controller52may determine that the engine speed should be further reduced to 800 RPM. Due to the further reduction, the controller52may wait an additional delay period at the block146before reducing the engine speed. During the further delay period, the operator may turn off the cold planer10and correspondingly stop the engine30.

Those skilled in the art will understand that the preceding exemplary operation of the cold planer10and the engine30may have been controlled by the routine170with similar results based on the configuration of the machine function demand table160and engine speed lookup table162. Moreover, the controller52and the routines130,170may be configured to be modified as necessary after installation in the cold planer10to tune the performance of the routines130,170. The controller52and the machine display110may be configured to allow an operator or technician to input data for the tables120,160,162where the components are not performing as designed in the field. The machine display110may facilitate making adjustments to the idle engine speeds produced for various combinations of active functions and active functions totals (tables120,162), and to the engine power demand values for the machine functions (table160). The controller52may also be configured to receive updates to the tables120,160,162from external devices. In various embodiments, the control console50may be provided with a connection port for an external device, such as parallel, serial or USB port, or the controller52may be operatively connected to an RF receiver, to facilitate downloading of the updates from the external device to the controller52. Additional mechanisms for downloading data to the controller52for the tables120,160,162will be apparent to those skilled in the art, and are contemplated by the inventors as having use in cold planers10and other machinery in which the auto engine speed control routines130,170may be implemented.