Engine speed management control system for cold milling

Abstract

Machine with: a motor (30), a rotor (24) which is configured to engage and disengage from the motor (30), a multitude of components, each operatively connected to the motor (30) to receive power from the motor (30) in order to perform a corresponding function of the machine, a large number of control switches (86 - 108), each corresponding to one of the functions performed by the large number of components of the machine and configured to provide a control signal according to an actuation status of the corresponding function, and a control unit (52) which is operatively connected to the motor (30) and the multitude of control switches (86 - 108), the control unit (52) is configured as follows: to allow the motor (30) to idle at a current idle speed corresponding to a current combination of active functions of the plurality of components based on the actuation states of the plurality of control switches (86 - 108) when the motor (30) is not engaged to drive the machine, to determine a new combination of active functions of the multitude of components based on the actuation states of the multitude of control switches (86 - 108) responding to the occurrence of a triggering event, to compare the new combination of active functions with the current combination of active functions, to set the current idle engine speed equal to a new idle engine speed corresponding to the new combination of active functions of the multitude of components, and to allow the engine (30) to idle at the new idle engine speed, responding to the determination that the new combination of active functions is not equal to the current combination of active functions and to store a machine function requirement table (160) with a motor power requirement value assigned to each function performed by one of the plurality of components, and to store a motor speed lookup table (162) with no-load motor speeds required to supply power for combinations of active functions that can be commanded by the plurality of control switches (86 - 108), wherein configuring the control unit (52) to compare the new combination of active functions with the current combination of active functions includes further configuring the control unit (52): to calculate a new sum of the active functions by summing the motor power requirement values ​​from the machine function requirement table (160) for the active functions of the new combination of active functions, and to compare the new sum of active functions with a current sum of active functions, where the current sum of active functions is equal to the sum of the motor power requirement values ​​from the machine function requirement table (160) for the active functions of the current combination of active functions, and wherein configuring the control unit (52) to allow the engine (30) to idle at the new idle engine speed includes further configuring the control unit (52): responding to the determination that the new sum of active functions is lower than the current sum of active functions, to initiate an initial delay period, to determine a first delay sum of the active functions after the first delay period has elapsed, wherein the first delay sum of the active functions is equal to the sum of the motor power requirement values ​​from the machine function requirement table (160) for the active functions after the first delay period has elapsed, and to let the engine (30) idle at the new idle speed without waiting for a second delay period responding to the determination that the first delay sum of the active functions is not less than the new sum of the active functions.

Description

Technical area

[0001] This disclosure relates generally to cold planers, and more particularly to systems and methods for controlling idle engine speeds of cold planers and other machines to optimize performance and fuel efficiency of the machines when operating various components powered by the engine. background

[0002] Cold planers, also known as asphalt recyclers, road milling machines, or road milling machines, are machines designed to scrape, remove, mix, or reclaim material from the surface of asphalt or concrete roads and similar surfaces. Cold planers typically have a plurality of tracks or wheels that adjustably support and transport the machine horizontally along the surface of the road being milled. Cold planers also feature a rotating milling rotor, or cutting device, which can be mechanically or hydraulically driven, to scrape and abrade the road surface as the cold planer travels. While the rotor scrapes the road surface, conveyors on the front of the cold planer transport the loose material and deposit it into the bed of a truck traveling in front of or alongside the cold planer.

[0003] The cold planer's tracks or wheels and rotor are driven by the machine's engine. 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 work together to regulate the amount of material removed by the rotor, to contain the removed material, and to transport the material to the collection vehicle. For example, the cold planer's vertical adjustment relative to the road surface can 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 excavates the surface.Side shields, located on each side of the rotor, are raised or lowered to provide a visual depth reference as the cold planer moves across the surface, to provide lateral containment of the rotor, and to hold the removed material together. The side shields are typically part of the grade control system and serve as the grade reference used by the control system. A form plate behind the rotor is positioned at a depth below that of the bottom surfaces of the side shields to scrape up loose material and clean the surface, requiring minimal additional cleanup after the cold planer completes a pass over the road surface.A plate guard in front of the rotor and in close proximity to the first conveyor stage is positioned slightly above the road surface to break up the material and prevent the rotor from picking up large pieces of material that are not easily transportable. A second conveyor stage carries the material up from the first conveyor stage and deposits it onto the truck. The second conveyor stage is moved up and down to change its angle, as well as from side to side to properly position the top of the conveyor based on the height and position of the truck. The legs, side shields, forming plate, plate guard, and conveyor assemblies can be hydraulically driven, with the hydraulics operated by a common pump powered by the engine.Cold planers typically have additional components that draw power from the engine, such as lights, generators, and air compressors.

[0004] Many of the cold planer's components can be operated while the cold planer is idling. For example, the positions of the legs, side shields, mold plate, plate guard, and second conveyor stage can be adjusted before engaging the rotor and completing a pass over the surface. In addition, the rotor can be engaged or disengaged when the engine is idling and not being driven. The engine speed required to provide sufficient pressurized fluid flow to drive the various components to perform the cold planer's functions varies based on the component being operated and the combinations of components simultaneously receiving power from the engine. Lights, generators, and air compressors may require low horsepower and low engine speeds to operate.In contrast, operating the jibs to raise or lower the cold planer simultaneously with repositioning the second discharge stage may require a greater amount of power via pressurized fluid flow, which is delivered by operating the engine at a higher engine speed. The operator does not always know the optimal speed necessary to perform the functions and is typically unable to make consistent adjustments to the engine speed. The operator may operate the engine at a speed too low to meet the demands of the operations or, more likely, may operate the engine at a speed higher than necessary to meet the demand, wasting fuel and generating more noise.

[0005] In view of this, there is a need for an engine speed management control system for cold planers that is capable of selecting an optimal engine speed to perform the requested operations based on the requested operations, while allowing the operator to transition the engine speed to a higher idle when maximum response and cycle times are required to perform the operations.

[0006] DE 10 2004 007 320 A1 discloses a method and a device for operating a motor vehicle. An idle speed to be set is variably specified for the speed of the associated engine. During driving, with traction in a drive train of the vehicle and the accelerator pedal released, the variably specified idle speed is set.

[0007] Furthermore, DE 44 05 340 A1 shows a method and a device for adjusting the speed of a drive unit of a vehicle when idling.

[0008] The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art. Summary of Revelation

[0009] The object of the present invention is achieved by a machine and by a method for controlling an idle engine speed of a machine according to the main claims. The subclaims relate to preferred embodiments of the invention. Short description of the drawings Fig. 1 is a side view of a cold planer having an engine speed management control system in accordance with the present disclosure; Fig. Figure 2 is a schematic illustration of the communication between the control unit, the control console and various controlled components of the cold planer from Fig. 1; Fig. 3 is an example engine speed table for non-milling operations and corresponding idle engine speeds; Fig. 4 is a flowchart illustrating one embodiment of an automatic engine speed control routine in accordance with the present disclosure used in the cold planer of Fig. 1 can be implemented; Fig. 5 is an example machine function demand table of engine power demand values ​​for non-milling operations; Fig. 6 is an example engine speed lookup table of the sums of the active functions for the engine power demand for non-milling operations and the corresponding idle engine speeds; and Fig. 7 is a flowchart illustrating an alternative embodiment of an automatic engine speed control routine in accordance with the present disclosure used in the cold planer of Fig. 1 can be implemented. Detailed description

[0010] Although the following text sets forth a detailed description of numerous different embodiments of the invention, it is to be understood that the scope of the invention is defined by the language of the claims set forth at the end of this patent. This detailed description is intended to be exemplary only and does not describe every possible embodiment of the invention, since describing all possible embodiments would be impractical, if not impossible. Numerous alternative embodiments could be implemented, either using current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims defining this invention.

[0011] It is also to be understood that it is not intended to limit the meaning of any term, either expressly or by implication, beyond its normal or ordinary meaning, unless a term is expressly defined in this patent using the phrase "As used herein, the term '_' shall be defined as..."; and such term shall not be interpreted as limited in scope based on any statement in any part of this patent (other than the language of the claims). To the extent that any term recited in the claims at the end of this patent is referred to in this patent in a manner consistent with a single meaning, it is done solely for clarity so as not to confuse the reader, and it is not intended that such claim term be limited, by implication or otherwise, to that single meaning.Finally, it is not intended that the scope of a claim element be interpreted based on the application of USC § 112, paragraph 6, unless a claim element is defined by reciting the word “means” and a function without reciting a structure.

[0012] A cold milling machine 10 is in Fig. 1 and may include a frame 12 supported for movement along a road surface 14 by a pair of front track assemblies 16 and a pair of rear track assemblies 18. The frame 12 is mounted on the track assemblies 16, 18 (only two of four track assemblies are shown in the side view of Fig. 1) are each supported by hydraulically actuated, adjustable struts or legs 20, 22, each extending between a pair of track assemblies 16, 18 and the frame 12. Hydraulic cylinders (not shown) are used to extend and retract the legs 20, 22 to raise and lower the cold planer 10.

[0013] A rotor 24 may be rotatably mounted on the frame 12 and may have a housing 26 surrounding it except for the body of the rotor 24, which is necessarily exposed to the road surface 14. The cutting or penetration depth of the cutting teeth (not shown) of the rotor 24 is controlled by appropriately extending or retracting the adjustable legs 20, 22 and the corresponding cylinders. The cold planer 10 also includes a motor 30 as a power source, which can drive the rotor 24 via a mechanical drive arrangement, which can include pulleys 32, 34, a belt 36, and a belt tensioner 38. As one skilled in the art will recognize, in addition to the Fig. 1, other arrangements may also be used, such as a gear train, a hydraulic system or another mechanism for converting the motor rotation into a rotation of the rotor 24.

[0014] The housing 26 may be constructed of several components that assist in holding together and removing the material from the road surface 14 that is excavated by the rotor 24, each of the components being vertically positionable to account for the depth to which the rotor 24 digs into the road surface 14. Side shields 40 (in Fig. 1 (only one shown in side view) may be disposed on either side of the rotor 24 and raised or lowered to provide a visual depth reference as the cold planer 10 moves across the road surface 14, as well as to provide lateral containment of the rotor 24 and to hold together the removed material. A shaping plate (not shown) may be disposed behind the rotor 24 and positioned at a depth below that of the bottom surfaces of the side shields 40 to scrape together the loose material and clean the road surface 14 so that minimal additional cleanup is required after the cold planer 10 has completed a pass across the road surface 14.A plate guard (not shown) disposed in front of the rotor 24 may be positioned slightly above the road surface 14 to break up the material and prevent the rotor 14 from picking up large pieces of material that are not easily transportable. The cold planer 10 may also include a first stage or receiving conveyor 42 that delivers the debris to a second stage or output conveyor 44. The output conveyor 44 and its associated framework or pulleys (not shown) may be carried by a telescoping arm 46; both are shown in FIG. Fig. 1 is only partially shown. Finally, the cold milling machine 10 may also include an operator area 48 with a control console 50 containing the necessary instruments to allow an operator to control the operation of the various components of the cold milling machine 10.

[0015] A control console 50 is partly in Fig. 2, which schematically shows the relationship between a control unit or engine control unit (ECM, electronic control module) 52 of the cold planer 10 and the other components relevant to the systems and methods described in the present disclosure. Of course, the control console 50 may also include gauges for water pumps, compressors, and other components, status indicators, additional switches, and the like, which have been omitted from the illustration and discussion for the sake of clarity of the disclosure. As shown in Fig. 2, the controller 52 may include a memory 54 and may also include a clock or timer 56. The controller 52 may be connected to the engine 30 and to a first clutch 58, which may be a hydraulically actuated clutch 58 coupled to the engine 30. The first clutch 58 may also be releasably engaged with the rotor 24, which may also be connected to the controller 52.

[0016] The cold planer 10 may further include at least one pump 60, which may be connected to the controller 52 to supply pressurized fluid flow to the hydraulic elements that cause the movements of the various components of the cold planer 10. The pump 60 may be coupled to the engine 30 through a second clutch 62, which may also be connected to the controller 52. The controller 52 may be capable of engaging and disengaging the second clutch 62 to alternatively couple and decouple the engine 30 and the pump 60. In the illustrated embodiment, the pump 60 may be coupled to multiple components of the cold planer 10 and supply hydraulic fluid to the various hydraulic elements as commanded by the controller 52.For example, pump 60 can supply pressurized fluid flow to the hydraulic elements of legs 20, 22, side shields 40, mold plate 64, platen guard 66, the drives of the pick-up and discharge conveyors 68 and 70, respectively, and the vertical and yaw angle controllers 72, 74 of the discharge conveyor, respectively. Control signals from controller 52 can cause pump 60 to direct fluid flow to the appropriate hydraulic elements as commanded by the operator.

[0017] The engine 30 can supply power to additional elements of the cold planer 10, which can be turned on and off based on the needs of the operator. For example, a generator 76, an air compressor 80, and lights 84 can be connected to the controller 52 and the electrical system of the cold planer 10, which is powered by the engine 30 when it is running. Those skilled in the art will appreciate that additional components controlled by the operator of the cold planer 10 and receiving power from the engine can be present in the cold planer 10.

[0018] Still referring to Fig. 2, the control console 50 may include a series of operator inputs to control the operation of the various components of the cold planer 10. Respective ON / OFF switches 86, 88, 90 for the lights 84, the generator 76, and the air compressor 80 may cause the controller 52 to turn the components on and off as needed. In the case of the generator 76 and the air compressor 80, placing the switches 88, 90 in the "ON" position may cause the controller 52 to operate the generator 76 and the air compressor 80, thereby drawing power from the engine 30. Vertical adjustment switches 92, 94, 96, 98 can be switched between “UP” and “DOWN” positions to control the height adjustment for the legs 20, 22, the side shields 40, the mold plate 64 and the plate guard 66, respectively.When one of the vertical adjustment switches 92, 94, 96, 98 is actuated in one of the settings, the controller 52 can cause the second clutch 62 to engage the motor 30 to transmit power to the pump 60 if the second clutch 62 is not already engaged, and cause the pump 60 to supply pressurized fluid flow to hydraulic elements of the components 20, 22, 40, 64, 66 according to the actuated switches 92, 94, 96, 98 to raise or lower the components.

[0019] ON / OFF switches 100, 102 for the drives of the receiving and output conveyors 68, 70 may also be provided. Setting the switches 100, 102 to the "ON" positions may cause the controller 52 to signal the second clutch 62 to engage the motor 30, if the second clutch 62 is not already engaged, to supply power to the pump 60, and cause the pump 60 to supply pressurized fluid flow to the drives of the conveyors 68, 70.If the speeds of the conveyors 42, 44 are controllable by the operator, the ON / OFF switches 100, 102 on the control console 50 may be replaced or supplemented by dials, potentiometers, or other control mechanisms capable of providing a variable signal to the controller 52 indicating the speeds at which the conveyors 42, 44 are to be operated, and the controller 52 may be programmed to transmit corresponding signals to the pump 60 to control the fluid flow transmitted to the conveyor drives 68, 70. Additional switches 104, 106 may be used to adjust the vertical angle orthe yaw angle of the output conveyor 44 by sending signals to the controller 52 to cause the pump 60 and the second clutch 62 to supply a fluid flow to the vertical angle controller 72 and the yaw angle controller 74 to move the output conveyor 44 to a desired position.

[0020] Controls for additional functionalities of the cold planer 10 may also be provided on the control console 50. An engine speed control switch 108 may be provided to allow the operator to select between engine speed control modes available for operating the cold planer 10. The operator may be provided with the ability to switch between an automatic engine speed control mode, as discussed in more detail below, and a high idle engine speed mode. The engine speed control switch 108 may allow the operator to switch between the modes.Setting the engine speed control switch 108 to the "AUTO" mode position may cause the controller 52 to control the speed of the engine 30 according to the strategy explained in detail below, while the "IDLE HIGH" setting may cause the controller 52 to idle the engine 30 at a predetermined speed, which may be greater than an engine speed that may be determined by the automatic engine speed control.

[0021] The controller 52 of the cold planer 10 may also be programmed with a service mode that also allows the operator to override the automatic engine speed control routine to operate the engine 30 at a desired engine speed. The service mode may be available to the operator for instances where the operator desires the engine 30 to 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 to troubleshoot problems with the cold planer 10. The service mode may be accessible via a machine display 110 on the control console 50.The operator may navigate to the service mode screen via the machine display 110 if provided in the form of a touch screen, via the engine speed control switch 108 if provided as an additional control option, or via additional controls that may be provided on the control console 50.

[0022] Once in service mode, the operator can select a desired engine speed from a range of engine speeds that may be selectable on the machine display 110. For example, the engine speed may be selectable from a range including a minimum speed of 800 rpm, a maximum speed of 1,900 rpm, and discrete intervals of 50 rpm therebetween. While in service mode, certain functions of the cold planer 10 may be partially locked by the controller 52. The operator may not be able to engage the rotor 24 or drive the cold planer 10 forward or reverse. The cold planer 10 may also be configured to prevent the operator from entering service mode while one of the functions that are locked when the cold planer 10 is in service mode is currently active.Once the operator has finished troubleshooting the cold planer 10, the operator may exit the service mode through the machine display 110 or other mode control switches.

[0023] When the cold planer 10 is running but idling, and the various components receiving power from the engine 30 are operated by the operator, the engine speed must increase to meet the components' power and pressurized fluid flow requirements. The operator may not know the engine speed necessary to meet the components' power demands and may instinctively increase the engine speed, but in doing so, may operate the engine 30 at a higher speed than is required to power the components. Running the engine 30 at a higher speed than necessary wastes fuel and unnecessarily increases the noise generated by the cold planer 10. The difficulty of operating the cold planer 10 is further increased for the operator attempting to operate the engine 30 closer to the speed required to power the components.In order to minimize fuel consumption by the cold planer 10, reduce average noise levels, and simplify operation of the cold planer 10 for the operator, the idle speed of the engine 30 may be automatically adjusted by the controller 52 based on the machine commands transmitted from the control console 50 to the controller 52 for operating the various components of the cold planer 10.

[0024] In one implementation of the cold planer 10, the controller 52 may be provided with a lookup table stored in memory or programmed into the control application program that may specify a speed at which the engine 30 should be operated based on the operation or combination of operations commanded by the operator when the cold planer 10 is idling. Fig. 3 illustrates an example of a table 120 containing information regarding engine speeds at which the controller 52 may idle the engine 30 when certain operations are commanded at the control console 50. As illustrated in the table 120, the various operations and components of the cold planer 10 may require varying power levels from the engine 30 for their operation. To meet the power requirements, the engine 30 may be caused to idle at engine speeds that correspond to the power requirements of the commanded operations. For example, during initial start-up, or when no operations are commanded by the operator, the controller 52 may idle the engine at a relatively low engine speed, such as 800 rpm.

[0025] When the operation of the various components is commanded by the operator at the control console 50, the controller 52 may respond by causing the engine 30 to operate at the engine speed listed in table 120. Different components draw different amounts of power from the engine 30, and consequently, different engine speeds are required to meet the power demands. Components such as the lights 84, the generator 76, and the air compressor 80 may require a relatively small amount of additional power for their operation. Subsequently, when one of the switches 86, 88, 90 is placed in its "ON" position, the controller 52 may respond by increasing the engine speed to 1,000 rpm. The components with hydraulic elements driven by the pump 60 may require a greater amount of power from the engine 30 and fluid flow from the pump 60 during their operation.As a result, the controller 52 may engage the second clutch 62 to drive the pump 60 and increase the engine speed to 1,300 rpm to cause the pump to drive the hydraulic elements of the commanded component.

[0026] During the course of operation of the cold planer 10, multiple operations may be commanded at the same time. The table 120 may be configured to run the engine 30 at an engine speed that meets the power requirements for the various commanded operations. Some combinations of operations may only require the engine 30 to 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 table 120 corresponding to one of the commanded operations. For example, if the operator sets the switches 90, 100 to their "ON" positions to operate the air compressor 80 and the pickup conveyor drive 68, the controller 52 may cause the engine 30 to operate at 1,300 rpm, which may provide sufficient power for both operations.

[0027] Other combinations of operations may require the motor 30 to operate at a higher speed than is required for each 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 motor speed may be further increased to ensure adequate system performance and sufficient fluid delivered to the hydraulic elements of the components. The specific amount of motor speed increase depends on the combination of functions being commanded. Via the example table 120, where two operations driven by the same pump are commanded, the controller 52 may cause the motor 30 to operate at 1,600 rpm. This may occur, for example, when the operator uses the switches 94, 96 to change the positions of the side shields 40 and 42, respectively.of the mold plate 64 up or down. Operations that place higher flow demands on the pump 60 may correspondingly require a higher motor speed. As described above, the conveyor drives 68, 70 may have different operating speeds, and the higher speeds may require a higher flow from the pump 60. The required flow may be provided by the controller 52 causing the motor 30 to further increase the motor speed to 1,900 rpm. A higher flow may also be necessary if more than two operations running from the same pump are commanded, and the table 120 may be configured to provide the necessary motor speed to meet the power and fluid flow requirements.Those skilled in the art will appreciate that the engine speed ranges set forth in Table 120 are merely exemplary in nature, and that the engine speed requirements for particular cold planers 10 and their components and operations will vary based on their design. Such variations are contemplated by the inventors as they apply to cold planers 10 consistent with the present disclosure.

[0028] Fig. 4 illustrates an exemplary automatic engine speed control routine 130 for controlling the idle speed of the engine 30 of the cold planer 10 or other types of machines or equipment that may perform operations that draw power from the engine 30 while the engine 30 is idling. Execution of the engine speed control routine 130 assumes that the engine speed control switch 108 is set to the "AUTO" position for automatic engine idle speed control and that the operator has not navigated into the service mode to control the engine speed via the machine display 110. The engine speed control routine 130 may begin at block 132, where the engine 30 may be started by an operator.Once the engine 30 is started, control may transfer to a block 134 where the controller 52 may set the engine speed to a low idle speed at which the engine 30 may initially operate and subsequently continue to operate while idling without any functions being active or commanded. The low idle speed may be provided by the data of table 120 as stored in memory 54 or programmed into control software implementing table 120. Once the engine speed is set, the engine 30 will operate at the low idle speed, such as 800 rpm as indicated in the exemplary table 120, until a function is commanded by the operator, the rotor 24 or drive mechanism for the cold planer 10 is engaged, or the engine 30 is shut down.

[0029] If the engine 30 of the cold planer 10 continues to idle, control may transfer to a block 136 where the controller 52 monitors the switches 86-106 for operator actuation to command a function of the cold planer 10. The controller 52 may check for operator actuation of the switches 86-106 at a sampling rate provided by the clock 56. After each monitoring period, control may transfer to a block 138 where the controller 52 may determine if a state of any of the switches 86-106 has changed since the previous monitoring period. If the states of the switches 86-106 are unchanged, control may transfer back to block 136 for continued monitoring of actuation of the switches 86-106.

[0030] If the controller 52 determines at block 138 that the state of one or more of the switches 86-106 has changed (e.g., changed from "OFF" to "ON" or "ON" to "OFF," or changed between "UP" or "DOWN," "LEFT" or "RIGHT," or back to the neutral position), control may transfer to a block 140 where the controller 52 may determine the engine speed corresponding to the combination of commanded functions indicated by the states of the switches 86-106. At block 138, the controller 52 may refer to the engine speed table 120 to determine the appropriate engine speed to provide sufficient power for the functions commanded by the operator via the switches 86-106. As discussed above, the controller 52 may be programmed with the necessary logic to convert the input provided by switches 86-106 to the engine speeds listed in table 120.Such logic may include a simple table lookup in a database stored in memory 54, hard-coded logic where each combination of actuated switches 86-106 outputs a predetermined engine speed, a combination thereof, or other programming techniques that perform the necessary conversion of inputs to output speeds.

[0031] After the controller 52 determines the new engine speed at block 140, control may transfer to block 142, where the controller 52 compares the new engine speed to the current engine speed to determine if 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 transfer to a block 144, where the controller 52 sets the engine speed to the new engine speed determined based on the engine speed table 120. Once the engine speed is set and the engine speed is increasing, control may transfer back to block 136, where the controller 52 may continue to monitor the states of switches 86-106 on the control console 50. At the same time, the controller 52 causes the commanded functions to be executed.

[0032] If it is determined at block 142 that the new engine speed is lower than the current engine speed and the engine is decelerating, it may be desirable to delay the engine deceleration to prevent a sudden deceleration of the engine followed by an immediate acceleration of the engine, which may cause additional stress on the engine 30 and fuel consumption. Instead, it may be preferable to wait for a specified period of time before decelerating the engine 30 to determine whether additional functional commands are input to the control console 50.As a result, if the new engine speed at block 142 is lower than the current engine speed, control may transfer to a block 146, where the controller 52 may use the timer 56 to provide a delay for a predetermined delay period, such as approximately three seconds, during which the operator may command additional functions or terminate functions. It should be noted that the delay period may not cause a corresponding delay in the execution of the requested machine functions.

[0033] After the delay period has expired, control may transfer to a block 148, where the controller 52 monitors the states of switches 86-106 to determine the combination of functions commanded by the operator in a manner similar to the monitoring performed at block 136. After the states of switches 86-106 and the corresponding combination of requested functions have been determined at block 148, control may transfer to a block 150, where the controller 52 may determine whether the combination of commanded functions has changed again.If the combination of commanded functions is unchanged, control may transfer to block 144 for controller 52 to set the engine speed to the new engine speed determined at block 140 so that the engine speed is reduced to the lowest engine speed necessary to support the commanded functions, as determined from engine speed table 120. Once the engine speed is set and the engine speed decreases, control may transfer back to block 136 for controller 52 to continuously monitor the states of switches 86-106 on control console 50. If it was determined at block 50 that the combination of commanded functions has changed during the delay period, control may transfer to block 140 for controller 52 to determine the appropriate engine speed for the new combination of commanded functions.

[0034] In an alternative implementation of cold planer 10, values ​​may be assigned to the machine functions performed by the various components of cold planer 10 based on the hydraulic flow demand placed on engine 30 when the components are operated to perform the machine functions. The engine power demand values ​​for the active machine functions may be summed and used by controller 52 to determine the idle speed of engine 30 required to deliver sufficient power to perform the active machine functions. Fig. 5 illustrates an example of a machine function demand table 160 that includes information regarding the machine functions that can be performed by the components of the cold planer 10, the active functional states of the components, and a motor power demand value for each machine function. For example, the front legs 22, as commanded by the actuation states of the switch 92, may have the functional states of raising and lowering the cold planer 10, and these functional states may require a motor power demand with a value of "3." The rear legs 20 may have similar functional states and be independently controlled by a separate control switch (not shown), but may require a higher motor power demand with a value of "4."The other machine functions discussed above, as well as additional machine functions, may each be assigned engine power demand values ​​in a similar manner, and those skilled in the art will recognize that additional control switches or other actuating means for activating the machine functions may be provided in the operator area 48 as needed.

[0035] Controller 52 may continuously monitor the operating states of the various machine functions, for example, by evaluating the actuation states of control switches 86-106. As the combination of active functions of the components changes, controller 52 may calculate a sum of the active functions' engine power demand values ​​from Table 160 for the active machine functions to determine the total engine power demand at a given time. The total engine power demand, as indicated by the sum of the active functions, may dictate the required idle engine speed to execute the active machine functions. Fig. 6 illustrates an alternative configuration of an engine speed lookup table 162 that may be stored by controller 52. The illustrated table 162 sums the idle engine speeds corresponding to the various sums of the active functions. As the combination of active machine functions, and accordingly the sum of the active functions, changes, the idle engine speed may increase or decrease over time, and controller 52 may adjust the speed of engine 30 accordingly.

[0036] Fig.7 illustrates an exemplary automatic engine speed control routine 170 for controlling the idle engine speed of the engine 30 of the cold planer 10 or other type of machine or equipment using the information in the machine function demand table 160 and the engine speed lookup table 162 when the control switch 108 is set to the "AUTO" position. The engine speed control routine 170 may begin at block 172, where the engine 30 may be started by an operator. Once the engine 30 is started, control may transfer to a block 174, where the controller 52 may set a current sum of the active functions equal to zero, allowing the engine 30 to initially idle at a low idle engine speed before the operator begins activating machine functions.Subsequently, at a block 176, the controller 52 may set the engine 30 to idle at an idle engine speed based on the value of the current sum of the active functions.

[0037] If the engine 30 of the cold planer 10 continues to idle, control may transfer to a block 178 where the controller 52 monitors the switches 86-106 for operator actuation to command a function of the cold planer. The controller 52 may check operator actuation of the switches 86-106 at a sampling rate provided by the clock 56, or may continuously monitor the activation states of the switches 86-106 and detect a change in the activation state of one or more of the switches 86-106. Upon the occurrence of a trigger event, such as the expiration of the sampling period or the detection of a change in an activation state, control may transfer to a block 180 where the controller 52 may calculate a new active function sum by summing the engine power demand values ​​from table 160 for the new combination of active machine functions.

[0038] The new sum of active functions may or may not require a change in idle engine speed. As with routine 130, routine 170 may allow the idle engine speed to be increased immediately, if necessary, when a new combination of active functions occurs, but if engine power demand decreases, wait for a prescribed delay period to determine if other machine functions are activated and would require an increase in idle engine speeds. After calculating the new sum of active functions, control may transfer to a block 182 to compare the new sum of active functions to the current sum of active functions. If the new sum of active functions is not less than the current sum of active functions, the idle engine speed may remain the same or increase.In this situation, control may transfer to a block 184 to set the current active function sum equal to the new active function sum and then to block 176 to adjust the idle engine speed based on the new value of the current active function sum.

[0039] Finally, if the new sum of active functions at block 182 is less than the current sum of active functions, it may be necessary to reduce the idle engine speed if no further changes are made to the combination of active functions. In this situation, control may transfer from block 182 to block 186, where controller 52 may implement timer 56 to provide a delay for a predetermined delay period, such as about three seconds, during which the operator can command additional functions or terminate functions. It should be noted that the delay period may not cause a corresponding delay in the execution of the requested machine functions.

[0040] After the delay period has expired, control may transfer to a block 188, which may calculate a delay sum of the active functions by summing the engine power demand values ​​from table 160 for the combination of active machine functions at the end of the delay period. After the delay sum of the active functions is calculated, control may transfer to a block 190, where the controller 52 may determine if the delay sum of the active functions is less than the new sum of the active functions calculated before the delay period. If the delay sum of the active functions is not less than the new sum of the active functions, the combination of active functions after the delay has the same engine power demand and requires the same idle engine speed, or an increase in the engine power demand and, therefore, a corresponding increase in the idle engine speed.In this situation, control may transfer to a block 192 to set the current active function sum equal to the active function delay sum and then to block 176 to adjust the idle engine speed based on the new value of the current active function sum.

[0041] If the current active function sum at block 190 is less than the new active function sum, it may be desirable to wait for further changes in the active function combination before reducing the idle engine speed. Subsequently, control may transfer from block 190 to block 194, where controller 52 may set the new active function sum equal to the active function delay sum, then to block 186 to begin a second delay period, and then to block 188 to calculate a second active function delay sum for the active function combination after the second delay period.The second delay sum of the active functions is then compared at block 190 with the new sum of the active functions to determine whether the idle engine speed should be reset or whether to continue to wait for additional delay periods until the combination of active functions and the corresponding sum of the active functions stops decreasing.

[0042] The engine speed control routines 130, 170, as described above, may be executed by the controller 52 during periods when the cold planer 10 is running but not being driven forward. In other operating states of the cold planer 10, the blocks of the engine speed control routines 130, 170 may be modified or overridden in their entirety based on the engine speed control requirements for the cold planer 10. In the service mode, as described above, the operator may, via the machine display 110, operate the engine 30 at a specific speed to troubleshoot problems with the cold planer 10. As another example, the automatic engine speed control routines 130, 170 may be active but modified to reflect the minimum engine speed requirements for the engaged rotor 24 when the cold planer 10 is in a static or non-driven state and the rotor 24 is engaged.The engine speeds specified in tables 120, 162 may be overridden to the extent they are lower than the minimum speed for the engaged rotor 24. For example, the minimum idle engine speed for the engaged rotor 24 may be 1,150 rpm, and the controller 52 may only modify the engine speed if the engine speed required for the commanded combination of active functions according to tables 120, 170 is greater than that required for the rotor 24. Where no operations are commanded, or only a combination with a relatively low engine power requirement for idle is commanded, the controller 52 may set the engine speed to 1,150 rpm at blocks 134, 144, or 176. If operation of a combination of active functions with a sufficiently high engine power demand is commanded, the controller 52 may adjust the engine speed to a suitable idle engine speed above 1,150 rpm.When enough active functions have been disabled by the operator to reduce the engine power requirement, the controller 52 reduces the engine speed back to the low idle speed of 1,150 rpm for the rotor 24 after the specified delay period.

[0043] Once the rotor is engaged and the engine 30 is engaged to drive the cold planer 10 forward, the automatic engine speed control routines 130, 170 may be deactivated. The engine speed may remain at the milling rotor speed requested by the operator at the controls provided in the operator area 48, such as 1,600, 1,750, or 1,900 rpm. Once the cold planer 10 has been stopped and the engine 30 is disengaged from the rotor, the engine speed control routines 130, 170 may be reactivated to allow the controller 52 to resume control of the idle engine speed of the engine 30.

[0044] The operator, or a technician, may have the ability to override the automatic engine speed control routines 130, 170 to dictate engine speeds necessary to perform certain operations or to test the cold planer 10. The operator or technician may have the ability to switch between the automatic engine speed control routines 130, 170 and forcing a high idle engine speed, such as 1,900 rpm. The operator may switch between the control mode and the high idle mode via the engine speed control switch 108 on the control console 50. Switching the engine speed control switch 108 to the "HIGH IDLE" position may cause the controller 52 to operate the engine 30 at the predetermined high idle engine speed.Switching the engine speed control switch 108 back to the "AUTO" position may reactivate the execution of the engine speed control routines 130, 170 by the controller 52. When the rotor 24 is engaged, the ability to switch between manual and automatic engine speed control modes may be disabled, and the engine speed may be dictated either by the desired rotor milling speed set by the operator as discussed above or by the engine speed control routines 130, 170 if no specific engine speed is commanded by the operator. Industrial applicability

[0045] In operation, the automatic engine speed control routines 130, 170 control the idle speed of the engine 30 of the cold planer 10. At the beginning of a milling job, an operator may start the engine 30 of the cold planer 10. In the following example, if the engine speed control switch 108 is set to "AUTO" using routine 130, the controller 52 may run the engine 30 at 800 rpm according to the engine speed table 120 at block 134. If a job is started first thing in the morning, the operator may set the light switch 86 to the "ON" position to turn on the lights 84. The controller 52 may detect the change in the state of the light switch 86 at block 138 and determine that the engine speed should be increased to 1,000 rpm at block 140. As the engine speed increases, the control unit 52 can adjust the engine 30 to the new engine speed at block 144 without waiting for a delay period.

[0046] Once the cold planer 10 is started and idling, the operator can position the rotor 24 and housing 26 in preparation for making the initial pass over the road surface 14. The operator can adjust the height of the rotor 24 via the legs 20, 22. Assuming that the rotor 24 is raised above the road surface 14, the operator can press the height adjustment switch 92 to the "DOWN" position to lower the rotor 24 into position. The controller 52 may detect actuation of the height adjustment switch 92 at block 136 and transmit control signals to the clutch 62 to engage and to the pump 60 to control the flow of hydraulic fluid to the actuators for the legs 20, 22 to lower the cold planer 10. The controller also determines at block 140 that the combination of the lights 84 and the movement of the legs 20, 22 results in an engine speed of 1.300 rpm, and sets the engine speed at block 144 to the increased idle speed.

[0047] Once the rotor 24 is in position, the operator may release the height adjustment switch 92 and allow the switch 92 to move to its neutral position. The change in state of the switch 92 may be detected by the controller 52 at block 138, and the controller 52 may send control signals to the pump 60 to interrupt actuation of the legs 20, 22. The controller 52 may determine at block 140 that the engine speed should be reduced to 1,000 rpm. The reduction in engine speed causes the controller 52 to transfer control from block 142 to block 146 for the timer 56 to count down the predetermined delay period, such as 3 seconds, to determine if other functions have been commanded by the operator. During the delay period, the engine speed is maintained at 1,300 rpm.

[0048] With the rotor 24 in position, the operator may actuate the side shield adjustment switch 94 and the mold plate adjustment switch 96 to begin adjusting the housing 26 by positioning the side shields 40 and the mold plate 64. The controller 52 may detect the actuation of switches 94 and 96 at blocks 148, 150 and return control to block 140 to determine the new engine speed. At the same time, the controller 52 may send control signals to the pump 60 to supply hydraulic fluid to the actuators for the side shields 40 and the mold plate 64. The controller 52 may determine at block 140 that the idle engine speed for performing two operations on the same pump 60 should be 1,600 rpm and may actuate the engine 30 at block 144 to idle at the new engine speed.

[0049] After the side shields 40 and mold plate 64 are in position, the operator may release switches 94, 96 to allow them to return to their positions and operate height adjustment switch 98 to position plate guard 66. Controller 52 may detect the change in state of switches 94, 96, 98 at block 136 and determine at block 140 that the appropriate engine speed to operate plate guard 66 is 1,300 rpm. Controller 52 may command pump 60 to suspend the flow of hydraulic fluid to the actuators for side shields 40 and mold plate 64 and to begin pumping hydraulic fluid to the actuator for plate guard 66, but may delay the decrease in engine speed during the delay period of block 146.If the delay period has expired and the height adjustment switch 98 is still actuated, the controller 52 can set the new engine speed at block 144 to slow the engine 30 to the specified flow. If the plate guard 66 is in position, the operator can release the height adjustment switch 98. The controller 52 can detect the change in state of the height adjustment switch 98 at block 136 and determine at block 140 that the engine speed should be reduced to 1,000 rpm because the lights 84 are still illuminated. The controller 52 may send control signals to the pump 60 to suspend the flow of hydraulic fluid to the plate guard actuator 66 and, after waiting for the delay period at block 146 to expire and detecting no further changes in the states of the switches 86-106, reduce the engine speed to 1,000 rpm at block 144.

[0050] Once the rotor 24 and housing 26 are positioned, the operator may use appropriate controls in the operator area 48 to engage the rotor 24. The controller 52 may detect engagement of the rotor 24 and set the low idle speed for the engine 30 to the specified engine speed for rotor engagement, such as 1,150 rpm. Before driving the cold planer 10 in the forward direction, the operator may engage the conveyors 42, 44 by setting the switches 100, 102 to their "ON" positions. The controller 52 may detect actuation of the switches 100, 102 at block 136. The delivery devices 42, 44 may place a high flow demand on the pump 60, and as a result, the controller 52 may determine at block 140 that the idle engine speed should be set to 1,900 rpm and may set the engine 30 to idle at that speed at block 144.At this point, the operator may engage the transmission of the cold planer 10 to propel the cold planer 10 forward for its initial pass over the road surface 14. Engaging the transmission may cause the controller 52 to deactivate the automatic engine speed control routine 130.

[0051] At the end of the job, after the cold planer 10 has completed its final pass over the road surface 14, the operator may disengage the transmission to stop the cold planer 10. The controller 52 may detect the transmission disengagement and re-enable the automatic engine speed control routine 130 to control the idle speed of the engine 30. If the rotor 24 remains engaged and the conveyors 42, 44 remain operating, the controller 52 may determine, based on the engine speed table 120, at block 140 that the appropriate engine speed is 1,900 rpm and adjust the engine speed to the new idle speed at block 144. After the cold planer 10 has stopped, the operator may disengage the rotor 24 and deactivate the conveyors 42, 44 by setting the switches 100, 102 to their "OFF" positions. The control unit 52 transmits control signals to the first clutch 58 to cause the clutch to disengage from the engine 30.The changes in the states of the switches 100, 102 may be detected by the controller 52 at block 136, and combined with the disengagement of the rotor 24, the controller 52 may determine at block 140 that the appropriate speed for the engine 30 is 1,000 rpm because the lights 84 are on but the rotor 24 is disengaged and the engine 30 no longer requires the increased low idle speed of 1,150 rpm.

[0052] The controller 52 may stop the conveying devices 42, 44 during the delay period of block 146 by transmitting control signals to the pump 60 to suspend the delivery of hydraulic fluid to the actuators of the conveying devices 42, 44. The controller may also send control signals to the second clutch 62 to disengage the engine 30 since no functions are commanded that require operation of the pump 60. If the operator turns off the lights 84 by setting the light switches 86 to the "OFF" position during the delay period, the controller 52 may turn off the lights 84 and return control of the engine speed control routine 130 from blocks 148, 150 back to block 140, where the controller 52 may determine that the engine speed should be further reduced to 800 rpm.Due to the further reduction, the controller 52 can wait for an additional delay period at block 146 before reducing the engine speed. During the further delay period, the operator can shut down the cold planer 10 and, accordingly, shut down the engine 30.

[0053] Those skilled in the art will appreciate that the above exemplary operation of the cold planer 10 and engine 30 could be controlled by routine 170 with similar results based on the configuration of the machine function demand table 160 and the engine speed lookup table 162. Furthermore, the controller 52 and routines 130, 170 may be configured to be modified as needed after installation in the cold planer 10 to tune the performance of routines 130, 170. The controller 52 and machine display 110 may be configured to allow an operator or technician to enter data into tables 120, 160, 162 if the components are not performing as designed in the field.The machine display 110 can facilitate making adjustments to the idle engine speeds generated for various combinations of active functions and sums of the active functions (tables 120, 162) and to the engine power demand values ​​for the machine functions (table 160). The controller 52 can also be configured to receive updates to the tables 120, 160, 162 from external devices. In various embodiments, the control console 50 can be provided with a connection port for an external device, such as a parallel, serial, or USB port, or the controller 52 can be operatively connected to an RF receiver to facilitate downloading the updates from the external device to the controller 52.Additional mechanisms for downloading data to the controller 52 for the tables 120, 160, 162 will be apparent to those skilled in the art and are contemplated by the inventors as applicable in cold planers 10 and other machines in which the automatic engine speed control routines 130, 170 may be implemented.

[0054] Although the foregoing text sets forth a detailed description of numerous different embodiments of the invention, it is to be understood that the scope of the invention is defined by the language of the claims set forth at the end of this patent.

Claims

[1] Machine with: an engine (30), a rotor (24) configured to engage and disengage from the motor (30), a plurality of components each operatively connected to the engine (30) to receive power from the engine (30) to perform a corresponding function of the machine, a plurality of control switches (86 - 108), each corresponding to one of the functions performed by the plurality of components of the machine and configured to provide a control signal corresponding to an actuation status of the corresponding function, and a control device (52) operatively connected to the motor (30) and the plurality of control switches (86 - 108), wherein the control device (52) is configured to: to idle the engine (30) at a current idle speed corresponding to a current combination of active functions of the plurality of components based on the actuation states of the plurality of control switches (86 - 108) when the engine (30) is not engaged to drive the machine, to determine a new combination of active functions of the plurality of components based on the actuation states of the plurality of control switches (86 - 108) in response to the occurrence of a trigger event, compare the new combination of active functions with the current combination of active functions, setting 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 idling the engine (30) 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 and storing an engine function demand table (160) having an engine power demand value associated with each function performed by one of the plurality of components, and storing an engine speed lookup table (162) having idle engine speeds required to supply power for combinations of active functions that can be commanded by the plurality of control switches (86 - 108), wherein configuring the controller (52) to compare the new combination of active functions with the current combination of active functions comprises the controller (52) being further configured: to calculate a new sum of the active functions by summing the engine power requirement values ​​from the machine function requirement table (160) for the active functions of the new combination of active functions, and to compare the new sum of the active functions with a current sum of the active functions, wherein the current sum of the active functions is equal to the sum of the engine power demand values ​​from the machine function demand table (160) for the active functions of the current combination of active functions, and wherein configuring the controller (52) to idle the engine (30) at the new idle engine speed comprises the controller (52) being further configured: in response to determining that the new sum of active functions is lower than the current sum of active functions, initiating a first delay period, to determine a first delay sum of the active functions after the expiration of the first delay period, wherein the first delay sum of the active functions is equal to the sum of the engine power demand values ​​from the machine function demand table (160) for the active functions after the expiration of the first delay period, and idle the engine (30) at the new idle engine speed without waiting for a second delay period in response to determining that the first delay sum of the active functions is not less than the new sum of the active functions. [2] The machine of claim 1, wherein the controller (52) is further configured to store a current actuation status value for each of the plurality of control switches (86-108), wherein the controller (52) is configured to determine that a new actuation status value in a control signal from at least one of the plurality of control switches (86-108) differs from the current actuation status value of the one of the plurality of control switches (86-108) stored in the controller (52), and wherein determining that the new actuation status value differs from the current actuation status value is the trigger event for determining the new combination of active functions. [3] The machine of claim 1, wherein configuring the controller (52) to idle the engine (30) comprises the controller (52) being configured: in response to determining that the rotor (24) is disengaged from the engine (30), equating a low idle engine speed to a low idle engine speed with the rotor (24) disengaged, in response to determining that the rotor (24) is engaged with the engine (30), equating the low idle engine speed to a low idle engine speed with the rotor (24) engaged, and in response to determining that no functions have been commanded by the actuation states of the plurality of control switches (86-108) to equalize the current idle engine speed to the low idle engine speed. [4] Machine according to claim 3, wherein the control device (52) is configured: comparing an idle engine speed required for the engine (30) to provide power to perform the new combination of active functions commanded by the actuation states of the plurality of control switches (86 - 108) with the low idle engine speed, and in response to determining that the low idle engine speed is higher than the idle engine speed required for the engine (30) to provide power to perform the new combination of active functions commanded by the actuation states of the plurality of control switches (86-108), setting the new idle engine speed equal to the low idle engine speed. [5] Machine according to claim 1, wherein the control device (52) is configured: storing an engine speed lookup table (162) with idle engine speeds required to deliver power for combinations of active functions that can be commanded by the plurality of control switches (86 - 108), and determine the new idle engine speed from the engine speed lookup table (162) based on the new combination of active functions commanded by the actuation states of the plurality of control switches (86 - 108). [6] The machine of claim 1, wherein configuring the controller (52) to idle the engine (30) at the new idle engine speed comprises the controller (52) being configured to idle the engine (30) at the new idle engine speed without waiting a delay period in response to determining that the new idle engine speed is higher than the current idle engine speed. [7] The machine of claim 1, wherein configuring the controller (52) to idle the engine (30) at the new idle engine speed comprises the controller (52) being configured: in response to determining that the new idle engine speed is lower than the current idle engine speed, initiate a delay period, to monitor the operating states of the plurality of control switches (86 - 108), and after expiration of the delay period, in response to determining that the actuation states of the plurality of control switches (86 - 108) have not changed during the delay period, idle the engine (30) at the new idle engine speed. [8] The machine of claim 7, wherein the controller (52) is configured to perform the steps of determining the new idle engine speed and comparing the new idle engine speed to the current idle engine speed in response to determining that the actuation states of the plurality of control switches (86-108) have changed during the delay period. [9] The machine of claim 1, wherein the controller (52) is configured to detect actuation of an engine speed control switch (108) to a high idle state based on the actuation state of the engine speed control switch (108), idle the engine (30) at a high idle engine speed in response to detecting the high idle state of the engine speed control switch (108), and maintain the high idle engine speed regardless of the combination of active functions of the plurality of components as long as the engine speed control switch (108) has the high idle state. [10] The machine of claim 1, wherein the trigger event for determining the new combination of active functions comprises the expiration of a predetermined period of time. [11] The machine of claim 1, wherein configuring the controller (52) to idle the engine (30) at the new idle engine speed comprises the controller (52) being further configured to idle the engine (30) at the new idle engine speed without waiting for a delay period in response to determining that the new sum of active functions is greater than the current sum of active functions, and wherein the new idle engine speed is equal to an idle engine speed from the engine speed lookup table (162) that corresponds to the new sum of active functions. [12] The machine of claim 1, wherein configuring the controller (52) to idle the engine (30) at the new idle engine speed comprises the controller (52) being configured: initiate the second delay period in response to determining that the first delay sum of the active functions is lower than the new sum of the active functions, to determine a second delay sum of the active functions after the expiration of the second delay period, wherein the second delay sum of the active functions is equal to the sum of the engine power demand values ​​from the machine function demand table (160) for the active functions after the expiration of the second delay period, and idle the engine (30) at the new idle engine speed without waiting for an additional delay period in response to determining that the second active function delay sum is not less than the first active function delay sum, wherein the new idle engine speed is equal to an idle engine speed from the engine speed lookup table (162) that corresponds to the second active function delay sum. [13] A method (170) for controlling an idle engine speed of a machine according to any one of the preceding claims, the method comprising: Causing (176) the engine to idle at a current idle speed corresponding to a current combination of active functions of the plurality of components based on the actuation states of the plurality of control switches (86-108) when the engine (30) is not engaged to drive the machine; Determining (178, 180) a new combination of active functions of the plurality of components based on the actuation states of the plurality of control switches (86 - 108) in response to the occurrence of a trigger event; Comparing (182) the new combination of active functions with the current combination of active functions; and setting (184) 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.

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