Patent Description:
It can be difficult to estimate an optimal engine speed for performing upcoming work at a desired rate. Therefore, many operators will select an engine speed to maximize power capability without fully taking into account the effect on fuel efficiency. It is typical of diesel engines to be the least fuel efficient when operating at an unnecessarily high engine speed with lower power utilization. The higher engine speed provides more power to the machine but decreases the fuel efficiency of the machine.

It would be desirable to have a power management system for the machine that can determine an engine speed that provides the required power while also optimizing fuel efficiency. This can reduce fuel consumption and help users better utilize the machine. <CIT> discloses a tachometer with economy indicator. <CIT> discloses a device and method for optimizing operation of a utility vehicle. The optimizing device enabling the microcomputer to generate optimized commands which are displayed on indicating means so that an operator can adjust the operating controls. <CIT> discloses vehicle performance advisory system comprising an electronic control unit that is able to maintain the same ground speed in progressively higher gears.

A power management system for a work machine is disclosed that includes a real time data interface configured to receive real time work machine data, and a processor configured to compute current machine power requirements based on the real time work machine data. The processor also computes an optimized engine speed based on the current machine power requirements and a desired reserve power, and informs an operator of the optimized engine speed. The processor also predicts upcoming machine power requirements based on the real time work machine data, and compute the optimized engine speed based on the current machine power requirements, the upcoming machine power requirements and the desired reserve power. The power management system also includes a predictive data interface to receive predictive data, and the processor can predict the upcoming machine power requirements based on the predictive data and the real time work machine data. The predictive data includes topographical data for a field to be harvested by the work machine.

The predictive data can include historical power-consumption data for the work machine, where the historical power-consumption data was collected when the work machine previously harvested one or more fields. The historical power-consumption data can include historical power-consumption data collected when the work machine previously harvested a current field to be harvested by the work machine, including recent historical data from the previous pass of the current field being harvested. This historical data can also be retrieved form geospatial data based on previous passes of the field, which were recorded by a prior map of the field.

The power management system can also include a mode selection control that enables the operator to select a manual mode and an automatic mode. When the automatic mode is selected, the power management system can automatically adjust work machine engine speed to the optimized engine speed. When the automatic mode is selected, the power management system can maintain a constant work machine ground speed as it automatically adjusts the work machine engine speed to the optimized engine speed.

The processor can compute the optimized engine speed based on a minimum engine operating speed and a machine reserve power curve. The processor can compute the optimized engine speed to reduce the brake specific fuel consumption value.

A power management method for a work machine is disclosed that includes receiving real time work machine data for the work machine; computing current machine power requirements based on the real time work machine data; computing a optimized engine speed based on the current machine power requirements and a desired reserve power; and informing an operator of the optimized engine speed. The power management method includes predicting upcoming machine power requirements based on the real time work machine data; and computing the optimized engine speed based on the current machine power requirements, the upcoming machine power requirements and the desired reserve power. The power management method includes receiving predictive data for the work machine; and predicting the upcoming machine power requirements based on the predictive data and the real time work machine data. The predictive data includes topographical data for a field to be harvested by the work machine.

The power management method can also include enabling the operator to select a manual mode and an automatic mode for the work machine; and when the automatic mode is selected, automatically adjusting work machine engine speed to the optimized engine speed. When the automatic mode is selected, the power management method can also include maintaining a constant work machine ground speed while automatically adjusting the work machine engine speed to the optimized engine speed.

The power management method can also include computing the optimized engine speed based on a minimum engine operating speed and a machine reserve power curve. The power management method can also include computing the optimized engine speed to reduce the brake specific fuel consumption value.

<FIG> illustrates a perspective view of a work machine <NUM> coupled to a head or implement <NUM>. The work machine <NUM> may have a power unit <NUM> that provides mechanical, electrical and hydraulic power to the work machine <NUM>, and can provide power to rotate a pair of drive wheels <NUM> coupled to a frame <NUM> of the work machine <NUM>. The drive wheels <NUM> may rotate relative to the work machine <NUM> to allow the work machine <NUM> to traverse an underlying or ground surface. In addition to drive wheels <NUM>, the embodiment shown in <FIG> has a pair of swivel caster wheels <NUM>. The caster wheels <NUM> may pivot freely about a mount to allow the work machine <NUM> to rotate as directed by the powered drive wheels <NUM> and caster wheels <NUM>. However, the particular configuration of the drive wheels <NUM> and caster wheels <NUM> should not be limiting. In a different embodiment, there may be no wheels at all. Rather, the power unit <NUM> may provide power to a pair of tracks to allow the work machine <NUM> to traverse the underlying surface. In yet another embodiment, the caster wheels <NUM> may not be swivel caster wheels but rather be wheels coupled to an axle and configured to be mechanically coupled to the power unit <NUM>.

The work machine <NUM> may also have a cabin <NUM> coupled to the frame <NUM>, and an implement mounting and positioning system <NUM> that can include lift arms, brackets, actuators and other mechanisms to connect and control the implement <NUM>. The cabin <NUM> may house a plurality of controls <NUM> that allow a user to control the various systems of the work machine <NUM> and the implement <NUM>. In one non-exclusive embodiment, the plurality of controls <NUM> are coupled to a control system <NUM> that monitors and send control signals to various mechanical, electrical, and hydraulic systems of the work machine <NUM> and the implement <NUM>. The plurality of controls <NUM> may be positioned in the cabin <NUM> and may include one or more touch screens, knobs, buttons, levers, or any other devices capable of identifying a user input.

It can be difficult to estimate an optimal engine speed for performing upcoming work at a desired rate. Therefore, many operators will select an engine speed to maximize power capability without fully taking into account the effect on fuel efficiency. It is typical of diesel engines to be the least fuel efficient when operating at an unnecessarily high engine speed with lower power utilization. The higher engine speed provides more power to the machine but decreases the fuel efficiency of the machine. The power management system can determine an optimized engine speed for the windrower that provides the required power and takes into account the fuel efficiency. This can reduce fuel consumption and help users better utilize the machine.

<FIG> illustrates an exemplary graph of engine speed versus engine power showing brake specific fuel consumption (BSFC) levels as contours and contour lines. The X-axis is engine speed measured in rotations per minute (rpm), and the Y-axis is engine power measured in kilowatts (kW). BSFC is a measure of the fuel efficiency of a machine that burns fuel and produces rotational, or shaft power. BSFC can be expressed in grams per kilowatt-hour or similar units. The lower the BSFC value, the greater the fuel efficiency.

<FIG> also shows a minimum engine operating speed line <NUM>, a maximum power curve <NUM> and a rated/reserve power curve <NUM>. In this exemplary graph, the minimum engine operating speed line <NUM> is at about <NUM> rpm, and the maximum power curve <NUM> drops off dramatically as the engine speed goes above about <NUM> rpm. The graph of <FIG> shows the BSFC levels decreasing as engine power approaches the maximum power curve <NUM> and the engine speed approaches the minimum engine operating speed <NUM>, meaning that low power-utilization at higher engine speeds produce lower fuel efficiency.

In this example, for a power requirement along the rated/reserve power curve <NUM>, the operator may initially operate the machine at a higher engine speed, such as <NUM> rpm which has a BSFC level of about <NUM>. The power management system would reduce or suggest reduction of the engine speed to a more fuel efficient region <NUM> where rpm is in the <NUM>-<NUM> range, the rated/reserve power curve <NUM> is at or near its maximum and the BSFC level is at or near its minimum of about <NUM>. The lower engine speed and BSFC value, <NUM> versus <NUM>, for the same or similar rated/reserve power shows the fuel efficiency improvement with little or no loss of available machine power. Engines are the most fuel efficient (fuel spent per work done) in the lower engine speed and the higher engine power utilization zone. The closer the machine is run to this higher engine power utilization zone <NUM> the better the fuel efficiency of the machine.

The power management system cannot control the required power level, but it can control the engine speed. The required power level is driven by the load. In the example of <FIG>, the operator is operating at a higher engine speed (<NUM> RPM) in conditions that require a lower power level (~90kW). So the machine could change the engine speed or recommend the engine speed be changed to a lower speed of <NUM> RPM, because this engine speed would still provide sufficient power overhead with the operator's current operating conditions. This change in engine speed would improve the static fuel efficiency only <NUM>-<NUM>/(kW-h). However, in addition to the static improvement, as the load or required power level varies during the operation, moving vertical on the BSFC plot, the improvement in fuel efficiency is even greater.

Power requirements can change for various reasons and it is desirable that the power management system leave some overhead to deal with these potential changes. If the power management system is determining an engine speed to meet current machine power demands and the machine goes up a hill, or encounters a thick region of crop, or encounters some other load increasing condition, it is desirable that the engine speed be able to deal with these circumstances without stalling or having to experience some other undesirable situation. The power management system can be configured to recognize an engine stall risk, and take action to avoid the engine stall. For example, the power management system can temporarily reduce the ground speed of the machine to reduce the vehicle load, or take some other action to attempt to allow the engine speed to recover and not stall.

The work machine <NUM> may include engine speed governing features that provide closed-loop speed control based on a set-point determined from several different configurable inputs. When operating under governor control, the desired power or torque command (and subsequently, fueling) is varied automatically to maintain the optimized engine speed. For instance, if the engine <NUM> suddenly comes under an increased load, as its speed drops, the governor responds by increasing fuel in order to maintain the optimized engine speed. If the engine <NUM> comes under an exceptionally high load, the governor power command may exceed the limits of the maximum power curve <NUM>. If this happens, fueling will be limited by the maximum power curve <NUM> curve and as a result the engine speed will continue to decrease until an equilibrium is achieved or the load decreases. This is considered a <NUM>% load condition.

The power management system can identify the current power requirements of the machine based on various parameters, for example based on current engine load, vehicle speed, harvesting settings, crop density sensor readings, etc. The harvesting settings can include, for example, header cutting speed, header load, etc. The control system <NUM> can be coupled to various systems and sensors on the machine <NUM> and implement <NUM> that provide the necessary information to the power management system to determine the current power requirements of the machine.

The power management system can also predict future or upcoming power requirements for the machine based on topographical field contour maps, upcoming crop density, machine power requirement history during harvesting, etc. Forward-looking sensors (for example, cameras, LIDAR or other sensors), positioning sensors and other sensors and databases on-board or off-board the machine can be used to supply data to predict upcoming power requirements. A machine learning model can help with the predictions by the power management system. The power management system and any associated machine learning model can collect current and historical power-consumption and related data that can be used to predict upcoming power requirements for the machine. This power-consumption data can include recent historical data from the previous pass of the field currently being harvested. This historical data can also be retrieved form geospatial data based on previous passes of the field, which were recorded by a prior map of the field.

This collected power-consumption and related data can be stored on-board and/or off-board the machine. This data can be collected over various conditions and various fields, and can then be used to predict upcoming machine power requirements when the same or similar conditions are expected to occur. In addition, when a field is harvested where power-consumption and related data had previously been collected, that previous power-consumption and related data can be used to predict upcoming machine power requirements for the same field.

The power management system can then determine the desired power level based on the current and predicted power requirements, and then find the optimized engine speed based on the BSFC levels. The power management system can then display and/or implement the optimized engine speed for operator reference.

The machine can include a mode selection control to enable the operator to select between a manual mode, an automatic mode, and possibly other power management modes. In the manual mode, the power management system can display the optimized engine speed for operator reference and the operator can decide whether or not to change the engine speed towards the optimized engine speed. In the automatic mode, the power management system can automatically adjust the machine engine speed smoothly towards the optimized engine speed, whether that requires ramping up or ramping down the engine speed.

<FIG> illustrates an exemplary display <NUM> that includes outputs from the power management system. The display <NUM> includes an upper section <NUM> with various machine status icons, a current engine speed display <NUM>, a current machine speed display <NUM>, and a power management display section <NUM>. The power management display section <NUM> includes a power gauge <NUM> and an optimized or target engine speed value <NUM>. In this example, the current engine speed display <NUM> shows <NUM> rpm, while the optimized or target engine speed value <NUM> determined by the power management system shows <NUM> rpm. So the power management system recommends that the engine speed be increased from <NUM> rpm to <NUM> rpm.

In some embodiments, the real-time data can be collected and used by power management system to monitor current and predicted power requirements of the machine <NUM>. The power management system can then determine a desired power level based on the current and predicted power requirements, and then determine an optimized engine speed based on the BSFC levels. The power management system can then inform the operator of the optimized engine speed or automatically implement the optimized engine speed.

In other embodiments, in addition to the real-time data, the power management system can have access to historical power-consumption and related data that can be used to help predict upcoming power requirements of the machine <NUM>. The power management system can then determine a desired power level based on the current and predicted power requirements using the real-time and historical data. The power management system can then determine an optimized engine speed based on the BSFC levels. The power management system can then inform the operator of the optimized engine speed or automatically implement the optimized engine speed.

In yet other embodiments, the historical power-consumption and related data can include data for the field currently being harvested which can also be used to help predict upcoming power requirements of the machine <NUM>. The power management system can then determine a desired power level based on the current and predicted power requirements using the real-time and historical data. The power management system can then determine an optimized engine speed based on the BSFC levels. The power management system can then inform the operator of the optimized engine speed or automatically implement the optimized engine speed.

In embodiments where the power management system automatically implements the optimized engine speed, it may be desirable that the ground speed of the machine remain constant. This can be implemented by various methods, including for example electronic control of the propulsion system of the machine <NUM>. The power management system can then automatically vary the engine speed to improve fuel efficiency while also varying power allocation to the propulsion system to maintain a desired ground speed of the machine <NUM>. It may be desirable to maintain a constant ground speed of the machine <NUM> to maintain coordination with other vehicles and systems during harvesting. The desired ground speed for the machine <NUM> can be controlled using the plurality of controls <NUM> and the control system <NUM>.

<FIG> illustrates an exemplary flow diagram for a power management system. At block <NUM>, the power management system collects and/or receives the real-time data for the machine <NUM> and implement <NUM>. At block <NUM>, the power management system accesses historical power-consumption and related data that can be used to help predict upcoming power requirements of the machine <NUM>. The historical power-consumption and related data can be stored on-board or remote from the machine <NUM>.

Claim 1:
A power management system for a work machine (<NUM>), the power management system comprising:
a real time data interface (<NUM>) configured to receive real time work machine data;
a processor configured to compute current machine power requirements (<NUM>) based on the real time work machine data; and the processor further configured to compute an optimized engine speed (<NUM>) based on the current machine power requirements and a desired reserve power, and to inform an operator of the optimized engine speed, and the processor is further configured to predict upcoming machine power requirements (<NUM>) based on the real time work machine data; and the processor is further configured to compute the optimized engine speed (<NUM>) based on the current machine power requirements, the upcoming machine power requirements and the desired reserve power, and the power management system further comprising a predictive data interface (<NUM>) configured to receive predictive data; wherein the processor is further configured to predict the upcoming machine power requirements (<NUM>) based on the predictive data and the real time work machine data, characterized in that, the predictive data includes topographical data for a field to be harvested by the work machine.