Agricultural machine, power control method and device thereof and medium

Abstract

The invention relates to the technical field of agricultural machinery, and discloses an agricultural machinery power control method comprising the following steps: estimating the initial demand generation power of the agricultural machinery according to the current complete machine operation condition of the agricultural machinery; on the basis of the power difference between the power generation request power of the agricultural machine at the previous moment and the actual power generation power at the current moment, a compensation correction value associated with the power generation efficiency is obtained; and based on the compensation correction value and a correction coefficient associated with atmospheric pressure, correcting the initial demand generation power to obtain final demand generation power. According to the embodiment of the invention, the influence of the power generation efficiency and the atmospheric pressure on the power generation power following precision is fully considered, and a corresponding compensation correction scheme is provided, so that the actual power generation power infinitely approaches the target power generation power, and the driving and operation requirements of agricultural machinery are met.

Description

Technical Field

[0001] The present application relates to the technical field of agricultural machinery, and in particular to an agricultural machinery and a power control method, device and medium thereof. Background Art

[0002] On the one hand, traditional fuel-powered agricultural machinery, such as a traditional fuel-powered harvester, has a structure as shown in Figure 1(a). It has many working parts and is powered directly by the engine. Part of the power is transmitted to the walking and operating mechanisms through multi-stage belts and hydraulic devices. It has the disadvantages of excessive transmission system load (some reach 6-stage transmission), high failure rate, and large vibration and noise. In addition, during the operation process, multiple functional modules of traditional fuel-powered harvesters are fixed speed ratios, which requires the engine speed to be fixed at a specific stage, resulting in limited engine utilization, difficult quantification, and limited energy efficiency optimization and improvement space. In addition, the changing operating environment and road conditions of the operation scene will cause the engine load of the traditional fuel-powered harvester to fluctuate disorderly, and the engine fuel utilization rate under unstable operating conditions is low. These objective reasons lead to bottlenecks in improving operating efficiency and optimizing energy consumption during the operation process of traditional fuel-powered agricultural machinery.

[0003] On the other hand, in the current social life, environmental and energy problems are becoming increasingly serious. Energy conservation, emission reduction, and low carbon have become the technological developments that will run through industrial vehicles and agricultural vehicles in the future. The current popular new energy technologies, due to their high efficiency, cleanliness, and environmental protection, are bound to be the only way to achieve sustainable development in the future. However, in agricultural machinery vehicles, due to the influence of conditions such as their operating environment and infrastructure, pure electric technology is limited in scenarios such as endurance and energy replenishment, and it cannot completely replace traditional fuel vehicles in a short period of time. In this case, the hybrid powertrain combines the advantages of high efficiency, low emissions, convenient energy replenishment, and convenient endurance, becoming the most effective transition method in current agricultural machinery.

[0004] However, in the hybrid power control system of agricultural machinery, although the conventional power following control method can make the engine run in the entire load range and basically run along the set optimal fuel consumption curve, considering the delay characteristics of hybrid generator power generation, the climate in plateau areas, etc., the current curve cannot meet driving and operating requirements. Summary of the invention

[0005] The purpose of the embodiments of the present application is to provide an agricultural machinery and a power control method, device and medium thereof, so as to at least partially solve the above-mentioned technical problems.

[0006] In order to achieve the above-mentioned objectives, the first aspect of the present application provides a power control method for agricultural machinery, comprising: estimating the initial required power generation power of the agricultural machinery according to the current operating condition of the entire agricultural machinery; obtaining a compensation correction value related to the power generation efficiency based on the power difference between the requested power generation power of the agricultural machinery at the previous moment and the actual power generation power at the current moment; and correcting the initial required power generation power based on the compensation correction value and a correction coefficient related to the atmospheric pressure to obtain the final required power generation power.

[0007] In an embodiment of the present application, before estimating the initial required power generation of the agricultural machinery, the power control method also includes: according to the driving information of the agricultural machinery, determining that the current operating condition of the whole machine is one of the operating condition, the unloading condition and the transfer condition; under the operating condition, the required power generation of the agricultural machinery includes the power required for the operation of the travel motor and all the operating motors; under the unloading condition, the required power generation of the agricultural machinery includes the power required for the operation of the unloading motor, wherein all the operating motors include the unloading motor; under the transfer condition, the required power generation of the agricultural machinery includes the power required for the operation of the travel motor.

[0008] In an embodiment of the present application, estimating the initial required power generation power of the agricultural machinery includes: estimating the required power of the hydraulic system of the agricultural machinery under the corresponding whole machine operating conditions; estimating the required power of the motor drive system of the agricultural machinery under the corresponding whole machine operating conditions, wherein the motor drive system includes a drive system for the travel motor and a drive system for the working motor; and adding the required power of the hydraulic system and the required power of the motor drive system to obtain the initial required power generation power.

[0009] In the embodiment of the present application, the following formula is used to correct the initial required power generation to obtain the final required power generation:

[0010]

[0011]

[0012] p req_i =p0+ΔP;

[0013] In the formula, p req is the final required power generation, p0 is the initial required power generation, ΔP is the compensation correction value, and p req_i is the intermediate value corrected based on the compensation correction value, K is the correction coefficient, B is the standard atmospheric pressure threshold, and P is the current atmospheric pressure.

[0014] In an embodiment of the present application, after obtaining the final required power generation, the method further includes: matching a high efficiency interval in the engine MAP characteristic curve of the agricultural machinery based on the final required power generation, and controlling the engine to operate at a speed corresponding to the matched high efficiency interval; determining the torque of the generator through the generator MAP characteristic curve of the agricultural machinery so that the actual power generation point of the generator is in the high efficiency interval in the generator MAP characteristic curve; and optimizing the engine speed and the torque of the generator in combination with the state of charge SOC of the power battery of the agricultural machinery.

[0015] In an embodiment of the present application, the optimization of the engine speed and the generator torque in combination with the power battery state of charge SOC of the agricultural machinery includes: when the SOC is in a preset battery high efficiency range, judging whether the power difference between the power generation request power of the agricultural machinery at the previous moment and the actual power generation power at the current moment is within the battery charging range, if so, maintaining the engine speed and the generator torque unchanged, otherwise, combining the battery power state SOP of the agricultural machinery and the actual power generation, re-matching the high efficiency range in the generator MAP characteristic curve and the engine MAP characteristic curve to obtain the optimized engine speed and the generator torque; and when the SOC exceeds or does not reach the battery high efficiency range, judging whether the power difference is within the battery discharge range, if so, maintaining the engine speed and the generator torque unchanged, otherwise, combining the battery power state SOP of the agricultural machinery and the actual power generation, re-matching the high efficiency range in the generator MAP characteristic curve and the engine MAP characteristic curve to obtain the optimized engine speed and the generator torque.

[0016] In an embodiment of the present application, the power control method also includes: obtaining the motor feedback power of the agricultural machinery during braking or shutdown of the working motor; determining the feedback torque based on the motor feedback power; and compensating the engine torque by the feedback torque.

[0017] A second aspect of the present application provides a power control device for agricultural machinery, comprising: a memory configured to store instructions; and a processor configured to call the instructions from the memory and to implement any of the above-mentioned power control methods when executing the instructions.

[0018] A third aspect of the present application provides an agricultural machine comprising any of the above-mentioned power control devices.

[0019] A fourth aspect of the present application provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable a machine to execute any of the above-mentioned power control methods.

[0020] Through the above technical scheme, the embodiment of the present application fully considers the influence of power generation efficiency and atmospheric pressure on the power generation tracking accuracy, and proposes a corresponding compensation correction scheme, so that the actual power generation is infinitely close to the target power generation, meeting the driving and operation requirements of agricultural machinery.

[0021] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0023] FIG1( a ) schematically shows a power system architecture diagram of a conventional fuel harvester;

[0024] FIG1( b ) schematically shows a power system architecture diagram of a range-extended hybrid harvester;

[0025] FIG. 1( c ) and FIG. 1( d ) schematically illustrate the engine fuel economy effects of the fuel engine model of FIG. 1( a ) and the hybrid engine model of FIG. 1( b ), respectively;

[0026] Figure 2 A schematic diagram of a flow chart of a power control method for agricultural machinery according to an embodiment of the present application is schematically shown;

[0027] Figure 3 A schematic diagram of power generation correction according to an embodiment of the present application is schematically shown;

[0028] Figure 4 A schematic diagram of a process for controlling engine speed and generator torque according to an embodiment of the present application is shown schematically;

[0029] Figure 5 A schematic diagram of a process for optimizing engine speed and generator torque according to an embodiment of the present application is schematically shown;

[0030] FIG6( a ) and FIG6( b ) schematically show an engine characteristic curve and a generator characteristic curve, respectively;

[0031] Figure 7 The schematic diagram shows a flow chart of an energy recovery control method according to an embodiment of the present application;

[0032] Figure 8A schematic diagram schematically shows a principle diagram of an exemplary energy recovery control according to an embodiment of the present application; and

[0033] Fig. 9 The structural block diagram of a power control device according to an embodiment of the present application is schematically shown. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0035] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0037] The solution of the embodiment of the present application is aimed at agricultural machinery. For the convenience of description, taking an extended-range hybrid harvester as an example, the system architecture of the agricultural machinery is first introduced in detail so that those skilled in the art can better understand the present application.

[0038] Figure 1(b) is a schematic diagram of the power system architecture of the extended-range hybrid harvester. The engine crankshaft output is directly connected to the generator system. During the walking and operation process, the generator is driven by the generator to generate electricity, supply energy to each drive module in the high-voltage power loop, and replenish the power battery at the same time. The front and rear axles and fans are controlled by an all-in-one drive control system, which is more compact in layout. At the same time, other modules such as the harvester, bridge, reel, intermediate shaft, etc. are replaced by motor direct drive. Therefore, compared with the traditional fuel harvester in Figure 1(a), the extended-range hybrid harvester adds motors to multiple power take-off ports, greatly simplifies the transmission mechanism and transmission circuit, and reduces the power loss in the transmission process. In addition, through the extended-range hybrid control system, it is easier to achieve reasonable energy allocation for each module during the operation process, so that the whole machine can achieve higher operating efficiency, as shown in Figure 1(c) and Figure 1(d), which respectively show the engine fuel economy effects of the fuel model in Figure 1(a) and the hybrid model in Figure 1(b). Obviously, the latter has better power performance and energy consumption performance.

[0039] Therefore, energy management strategy is crucial for extended-range hybrid harvesters. Through efficient and stable energy management strategy, the whole machine can have better performance in power performance and energy consumption performance, and power control is part of the energy management strategy.

[0040] However, compared with conventional new energy vehicles, agricultural machinery is not only required to be able to travel under various road conditions, but also to ensure high-efficiency operation. This means that agricultural machinery has multiple operating parts, such as the fan and reel shown in Figure 1(b), and has special whole-machine operating conditions. When designing energy management strategies, it is necessary to understand the whole-machine operating conditions of agricultural machinery. Therefore, taking the extended-range hybrid harvester in Figure 1(b) as an example, the operating conditions, field transfer conditions, and grain unloading conditions are introduced as follows.

[0041] In the operation condition, the header is adaptively lifted to a specific height by the system, the drum motor and bridge are started to the set speed, and the reel adapts to the specific speed according to the real-time vehicle speed to meet the changing crop feeding amount. The whole machine responds to the target speed of the driving handle to maintain the stable operation speed of the operation process. At this time, the power module loop includes the travel motor, battery, generator, drum and other operating parts (fan motor, reel motor, bridge motor, intermediate shaft, etc.).

[0042] In the grain unloading condition, this scenario is generally static grain unloading, that is, the grain in the granary is transported to the synchronous grain transport vehicle through the operation of the stirring cage. During the grain unloading process, only the grain unloading motor drives the stirring cage and the elevator to work. The actual power required for the whole process is relatively small, and the required power can usually be provided by the power battery alone.

[0043] In the transition condition, the scene is mainly walking, and the motors of other operating modules have no power requirements. Therefore, the main working parts are the engine, generator, power battery and walking motor. The power requirements during walking are complex. Factors such as road conditions, walking slope, machine weight, speed, etc. all affect the power of the whole machine. The overall power is small but the linear span is large.

[0044] In view of these complex machine operation conditions, it is necessary to design energy management strategies specifically. In the design of energy management strategies, it is involved to use power following control methods to calculate the power generation of the generator. However, in conventional power following control methods, the influence of factors such as power generation delay and low atmospheric pressure are not considered, and the determined optimal fuel consumption curve cannot meet the actual driving and operation requirements. Therefore, the embodiment of the present invention proposes a new power control scheme for agricultural machinery.

[0045] Figure 2 The following schematically shows a flow chart of a power control method for agricultural machinery according to an embodiment of the present application. Figure 2 As shown, the power control method may include the following steps:

[0046] Step S100, estimating the initial required power generation power of the agricultural machinery according to the current whole machine operating condition of the agricultural machinery.

[0047] It should be noted that the current operating condition of the whole machine can be determined to be one of the operating condition, unloading condition and transfer condition based on the driving information of the agricultural machinery, such as the information about the vehicle's driving indicated by the machine's throttle signal, brake signal, gear signal, working mode signal, etc. (conventional information such as throttle opening, steering wheel angle, vehicle speed, etc.), and then the initial required power generation power can be calculated accordingly.

[0048] According to the above introduction to the three working conditions, it can be known that: under the operating condition, the required power generation power of the agricultural machinery includes the power required for the operation of the travel motor and all the working motors; under the grain unloading condition, the required power generation power of the agricultural machinery includes the power required for the operation of the grain unloading motor, wherein the all the working motors include the grain unloading motor, i.e., under this condition, there is no need to consider the power requirements of the travel motor and other working motors; under the transfer condition, the required power generation power of the agricultural machinery includes the power required for the operation of the travel motor, i.e., under this transfer condition, there is no need to consider the power requirements of the working motor.

[0049] For step S100, estimating the initial required power generation of the agricultural machinery may include: estimating the required power of the hydraulic system of the agricultural machinery under the corresponding whole machine operating conditions; estimating the required power of the motor drive system of the agricultural machinery under the corresponding whole machine operating conditions, wherein the motor drive system includes a drive system for the travel motor and a drive system for the working motor; and adding the required power of the hydraulic system and the required power of the motor drive system to obtain the initial required power generation. The power demand of the hydraulic system includes the power demand of components that rely on hydraulic control, such as brakes and turn signals, and the power demand of the motor drive system can refer to Figure 1(b), involving the power demand of the travel motor, drum motor, bridge motor, fan, reel, cutter motor, power battery, etc.

[0050] In addition, the specific power demand can be determined based on driving intention and driving information. For example:

[0051] 1) Estimate the power demand Pm of the travel motor according to the real-time throttle opening and the rate of change of the opening and the current speed of the travel motor.

[0052] 2) Estimate the power requirements of the drum motor Pg, the bridge motor Pb, and the reel motor Pw based on the current speed of the vehicle and the rate of change of the current speed.

[0053] 3) Calculate the fan motor power Pf of the fan at the current moment (the fan power requires a constant speed, and the power does not change much when the speed is switched in a small range. The actual power output is the target demand power).

[0054] 4) Calculate the power requirements Ps of other components.

[0055] The method for determining the power requirements of each component is conventional and will not be described in detail below.

[0056] It can be seen that the estimated initial required power generation and final generator power can both reflect the state of the whole machine, which can be understood below as corresponding to the required power of the whole machine at different stages.

[0057] Step S200: obtaining a compensation correction value associated with power generation efficiency based on the power difference between the power generation request power of the agricultural machinery at the previous moment and the actual power generation power at the current moment.

[0058] For example, under operating conditions, the extended-range architecture allows the engine and other actuators to be decoupled. Therefore, the engine speed and generator torque can be dynamically adjusted according to the state and trend of the whole machine, so that the power generation follows the power demand of the whole machine. In addition, step S200 takes into account the influence of the delay of power generation (i.e., power generation efficiency) on the power following accuracy, and proposes a compensation correction value for power compensation. The calculation process of the compensation correction value is, for example: Calculate the power generation request power p at the previous moment rreq And the actual power generation P at the current moment real , the compensation correction value ΔP of the generated power is obtained by the actual power difference between the two, where a positive value indicates enhancement and a negative value indicates reduction. By applying the compensation correction value to the next calculation cycle, the actual generated power can be infinitely close to the requested generated power to compensate for the influence of power generation efficiency and errors.

[0059] Step S300: correcting the initial required power generation power based on the compensation correction value and a correction coefficient associated with the atmospheric pressure to obtain a final required power generation power.

[0060] It should be noted that atmospheric pressure determines the oxygen content of the same engine intake volume, and thus it is negatively correlated with the engine's fuel combustion efficiency. Therefore, the influence of atmospheric pressure needs to be considered in the actual operation of agricultural machinery.

[0061] In this regard, combining step S200 and step S300, the following formula can be used to correct the initial required power generation power:

[0062]

[0063]

[0064] p req_i =p0+ΔP

[0065] In the formula, p req is the final required power generation, p0 is the initial required power generation, ΔP is the compensation correction value, that is, ΔP = p rreq -p real , p req_i is an intermediate value corrected based on the compensation correction value, K is a correction coefficient associated with the atmospheric pressure, B is a standard atmospheric pressure threshold, and P is the current atmospheric pressure.

[0066] Thus, for the above steps S100-S300, combined with Figure 3 The power generation power correction schematic diagram shows that after obtaining the final required power generation power, the embodiment of the present application can further design an energy management strategy.

[0067] In the preferred embodiment of the present application, combined with Figure 3 And if Figure 4 As shown, the designed energy management strategy can optimize the engine speed and generator torque through the following steps:

[0068] Step S401 : matching a high efficiency interval in a MAP characteristic curve of an engine of an agricultural machine based on the final required power generation, and controlling the engine to run at a speed corresponding to the matched high efficiency interval.

[0069] For example, the power demand of the whole machine (i.e. the final required power generation, including the estimated initial required power generation and the compensation correction power of the previous cycle) is calculated, and then combined with the charge and discharge characteristics of the SOC and the generator MAP characteristic curve, a high-efficiency interval matching the final required power generation can be found in the engine MAP characteristic curve, so that the engine can run at the corresponding speed in the high-efficiency interval. It should be noted that the power demand of the whole machine can also include the friction power of the engine, which reflects the process loss power of the engine output, including transmission loss power, shaft end loss power, etc.

[0070] Step S402: determining the torque of the generator through the generator MAP characteristic curve of the agricultural machinery so that the actual power generation point of the generator is in a high efficiency range in the generator MAP characteristic curve.

[0071] Step S403, optimizing the speed of the engine and the torque of the generator in combination with the SOC of the power battery of the agricultural machinery.

[0072] Thus, step S402 and step S403 determine the initial engine speed and generator torque using the motor characteristic curve, and then step S403 performs optimization in combination with the battery SOC. In a more preferred embodiment of the present application, the optimization method is, for example:

[0073] When the SOC is in a preset battery high efficiency range, determine whether the power difference between the power generation request power of the agricultural machinery at the previous moment and the actual power generation power at the current moment is within the battery charging range. If so, maintain the engine speed and the torque of the generator unchanged; otherwise, combine the SOP (battery power status) of the agricultural machinery and the actual power generation power to re-match the high efficiency range in the generator MAP characteristic curve and the engine MAP characteristic curve to obtain the optimized engine speed and generator torque.

[0074] When the SOC exceeds or does not reach the battery high efficiency range, it is determined whether the power difference is within the battery discharge range. If so, the engine speed and the generator torque are maintained unchanged. Otherwise, based on the battery power state SOP of the agricultural machinery and the actual generated power, the high efficiency range is re-matched in the generator MAP characteristic curve and the engine MAP characteristic curve to obtain the optimized engine speed and generator torque.

[0075] For example, Figure 5 As shown in the figure, the optimal working SOC target threshold area [SOCmin, SOCmax] under SOC conditions is defined by the battery performance parameter curve. The power battery has the best charging and discharging performance in the target threshold area, so that the battery performance can be maximized to supplement the generator's transient response curve, so that the two can be well complemented, and finally the ideal generator torque and engine speed information can be obtained. Figure 5 , Pbat is used to represent a power threshold window that allows the power battery to be charged to discharged under the current SOC, temperature and other conditions. Therefore, the battery state, that is, the current battery SOC, can be properly charged to the power threshold window of proper discharge. Since the target SOC has a dynamic stable interval, the size of the SOC value determines the boundary of the power threshold window (the larger the SOC, the larger the lower boundary of the power threshold, which tends to be charged; the smaller the SOC, the larger the upper boundary of the power threshold window, and the more it tends to be discharged). At this time, Figure 5 The power difference actually refers to the difference between the last power generation request value and the power generation request value of this cycle. If this difference satisfies Pbat in the previous step, it is considered that the current system can meet the power requirement and the system does not make any adjustments. Otherwise, a new high-efficiency power point needs to be recalculated.

[0076] According to the engine and generator characteristic curves shown in Figure 6(a) and Figure 6(b), there is a transmission mechanism from the engine to the generator, that is, a gearbox with a transmission ratio of K. During the matching process, attention should be paid to the matching relationship between torque and speed. It is necessary to obtain a speed and torque range corresponding to the total power output of the engine (speed and torque determine a mapping point), and these ranges are also highly efficient in the generator characteristics (or relatively high, with the second highest priority, and the mapping optimization process is mainly based on the engine). In this way, refer to Figure 5 , after determining the power difference between the requested power at the previous moment and the actual power at the current moment, it will give priority to whether there are other efficient points in the determined mapping points that meet the current scenario under the premise that the current speed remains unchanged. Otherwise, it will search left (in the direction of low power) or right (in the direction of high power) until a suitable mapping point is found to meet the current power demand.

[0077] Back to Figure 3 The energy management strategy further includes the power output coordination of the power battery and the generator. For example, in the grain unloading condition, since the power of the grain unloading condition is small and the demand is single, the grain unloading condition is mainly distinguished by the SOC situation. When the SOC is less than SOCmin, the engine starts, and the generator considers charging the power battery while supplying energy to the grain unloading mechanism. At this time, it is necessary to find a suitable efficiency range for the engine. If the SOC is greater than SOCmax, the engine stops, and the grain unloading power is mainly supplied by the power battery. Therefore, under the condition of high-efficiency function of the whole machine battery, the efficiency of the grain unloading condition is relatively high.

[0078] That is, according to the SOC of the power battery, when the SOC is greater than the set threshold, the engine is turned off and the power battery is used to drive the grain unloading related modules to unload the grain. When the SOC is less than the set threshold, the engine speed and the generator torque are set according to the effective average power of the grain unloading process and the current battery power, so that the engine has a higher efficiency at this speed. At this time, the engine is the power source of the whole machine, part of which is used to maintain the needs of the grain unloading process, and the other part is used to charge the battery.

[0079] For example, in the transition condition, the main power demand of the vehicle is the walking power, and there is no other power input except the hydraulic system. At this time, the power following of the vehicle is implemented by rules and multi-condition constraints. For example, the power battery threshold of the transition scene can be defined. When the power battery SOC threshold is large, the walking process can be pure electric, that is, the battery is the only power source. When the battery SOC threshold is small, it is consistent with the working condition. For example, refer to the above Figure 2 and Figure 4 That is, the low-power battery needs to increase the charging weight, and in the overall trend, a dynamic equilibrium state can be achieved.

[0080] After determining the engine speed and generator torque above, the VCU (vehicle control unit) of the agricultural machinery sends the target speed to the engine ECU to respond to the power demand at the next moment. At the same time, the VCU sends the target generator torque to the generator MCU in a single-step accumulation manner (the step size is calibrated according to the actual site) to reduce the crankshaft impact caused by the rapid mutation of the engine load, and also allows the engine to respond at a stable rate to avoid overload and flameout.

[0081] In a preferred embodiment, Figure 7 As shown, the above energy management strategy may also include:

[0082] Step S701, obtaining the motor feedback power of the agricultural machinery during the braking process or the shutdown process of the working motor.

[0083] Step S702: determining the feedback torque based on the motor feedback power.

[0084] Step S703: compensating the torque of the engine by using the feedback torque.

[0085] The above steps S701-S703 are described in detail below through examples. Figure 8 is a schematic diagram of an example of energy recovery control. Figure 8 As shown, taking the extended-range hybrid harvester of Figure 1(b) as an example, the recovery power (i.e., motor feedback power) is the kinetic energy of the drum stop process and the whole harvester walking brake stop process recovered by the corresponding motor, and then combined with the characteristic efficiency η and moment of inertia J of the drum motor or the walking motor at the current speed, the recoverable power value within the calibration time and the theoretical power generation torque M after the calibration time are calculated. The specific algorithm is shown in the following formula:

[0086]

[0087] Since the target SOC and the battery's SOP, that is, the battery state, actually determine the charging power of the whole power battery, after obtaining the theoretical power generation torque, it is necessary to output the feedback torque in combination with the current battery state, the current state of the whole generator, etc. For example, under the current battery SOC, it can be properly charged to the power threshold window of appropriate discharge. Since the target SOC has a dynamic stability interval, the size of the SOC value determines the boundary of the power threshold window (the larger the SOC, the larger the lower boundary of the power threshold, which tends to be charged; the smaller the SOC, the larger the upper boundary of the power threshold window, and the more inclined to the discharge trend). At this time, the feedback torque needs to meet the following requirements: the output torque is within the generator's limit torque range; the output torque power is converted through efficiency, and the power generation current cannot cause the power battery to overcharge; it needs to meet the smoothness and non-stuttering of the vehicle's deceleration and braking process after loading.

[0088] Figure 8 The energy recovery interference compensation mainly refers to the compensation for efficiency conversion. The theoretical recovered power value will be different from the conversion value due to efficiency reasons. Therefore, this part needs to be superimposed on the recovered power input through additional compensation and finally act on the torque of the generator.

[0089] In this way, by optimizing and adding energy recovery strategies, the existing energy management strategies are enriched, so that the motor feedback power can be used to replenish the power battery during the braking process of the entire machine and the drum shutdown process.

[0090] In summary, the power control method of the embodiment of the present application fully considers the influence of power generation efficiency and atmospheric pressure on the following accuracy during the power following process, and proposes to perform compensation correction in the next calculation cycle, so that the actual power generation is infinitely close to the target power generation, avoiding the overcharging or over-discharging of the battery due to the large difference between the target power generation and the actual power generation, which is beneficial to the service life of the battery. In addition, because the embodiment of the present application realizes the correction of the target power generation, on the one hand, it can ensure that the entire hybrid system can have sufficient power response, and on the other hand, it can also ensure good driving followability under the premise of optimal fuel consumption and NVH performance. That is, under the premise of ensuring the output power, the stability of the engine is met and the energy-saving goal is achieved. In addition, the embodiment of the present application also introduces an energy recovery strategy, which enriches the entire energy management process and is more conducive to achieving the energy-saving goal.

[0091] Fig. 9 The structure block diagram of a power control device for agricultural machinery according to an embodiment of the present application is schematically shown. Fig. 9 As shown, the power control device may include: a memory configured to store instructions; and a processor configured to call instructions from the memory and implement the above-mentioned power control method when executing the instructions. In an example, the power control device is, for example, a vehicle controller of a harvester or a separately configured controller.

[0092] The embodiment of the present application further provides an agricultural machine, including the above-mentioned power control device. The agricultural machine is, for example, the above-mentioned extended-range hybrid harvester, but is not limited thereto. In other examples, it may also be a baler, a transplanter, or various types of tractors.

[0093] An embodiment of the present application further provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable a machine to execute the above-mentioned power control device.

[0094] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0095] The present application is described with reference to the flowchart and / or block diagram of the method, device (system), and computer program product according to the embodiment of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the process and / or box in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one process or multiple processes in the flowchart and / or one box or multiple boxes in the block diagram.

[0096] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0097] These computer program instructions may also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0098] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0099] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0100] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0101] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0102] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A power control method for agricultural machinery, characterized in that: include: estimating the initial required power generation power of the agricultural machinery according to the current whole machine operating condition of the agricultural machinery; Based on the power difference between the power generation request power of the agricultural machinery at the previous moment and the actual power generation power at the current moment, obtaining a compensation correction value associated with power generation efficiency; and Based on the compensation correction value and a correction coefficient associated with the atmospheric pressure, the initial required power generation power is corrected to obtain a final required power generation power.

2. The power control method according to claim 1, characterized in that: Before estimating the initial required power generation power of the agricultural machinery, the power control method further includes: According to the driving information of the agricultural machinery, determining that the current whole machine operating condition is one of an operating condition, a grain unloading condition and a field transfer condition; Under the operating conditions, the required power generation of the agricultural machinery includes the power required for the operation of the travel motor and all the operating motors; In the grain unloading condition, the required power generation power of the agricultural machinery includes the power required for the operation of the grain unloading motor, wherein all the operating motors include the grain unloading motor; Under the field transfer condition, the required power generation power of the agricultural machinery includes the power required for the operation of the travel motor.

3. The power control method according to claim 2, characterized in that: Estimating the initial required power generation of the agricultural machinery includes: estimating the required power of the hydraulic system of the agricultural machinery under the corresponding whole machine operating conditions; estimating the power demand of the motor drive system of the agricultural machinery under the corresponding whole machine operating conditions, wherein the motor drive system includes a drive system for the travel motor and a drive system for the working motor; and The required power of the hydraulic system and the required power of the motor drive system are added together to obtain the initial required power generation power.

4. The power control method according to claim 1, characterized in that: The initial required power generation is corrected by the following formula to obtain the final required power generation: p req_i =p0+ΔP; In the formula, p req is the final required power generation, p0 is the initial required power generation, ΔP is the compensation correction value, and p req_i is the intermediate value corrected based on the compensation correction value, K is the correction coefficient, B is the standard atmospheric pressure threshold, and P is the current atmospheric pressure.

5. The power control method according to claim 1, characterized in that: After obtaining the final required power generation power, the method further includes: Matching a high-efficiency working interval in the engine MAP characteristic curve of the agricultural machinery based on the final required power generation, and controlling the engine to operate at a speed corresponding to the matched high-efficiency interval; Determining the torque of the generator by means of a MAP characteristic curve of the generator of the agricultural machinery so that the actual power generation point of the generator is in a high efficiency interval in the MAP characteristic curve of the generator; and The engine speed and the generator torque are optimized in combination with the state of charge (SOC) of the power battery of the agricultural machinery.

6. The power control method according to claim 5, characterized in that: The optimizing the speed of the engine and the torque of the generator in combination with the state of charge SOC of the power battery of the agricultural machinery comprises: When the SOC is in a preset battery high efficiency interval, determine whether the power difference between the power generation request power of the agricultural machinery at the previous moment and the actual power generation power at the current moment is within the battery charging range, if so, maintain the speed of the engine and the torque of the generator unchanged, otherwise, combine the battery power state SOP of the agricultural machinery and the actual power generation power, re-match the high efficiency interval in the generator MAP characteristic curve and the engine MAP characteristic curve to obtain the optimized engine speed and the torque of the generator; and When the SOC exceeds or does not reach the battery high efficiency range, it is determined whether the power difference is within the battery discharge range. If so, the engine speed and the generator torque are maintained unchanged. Otherwise, based on the battery power state SOP of the agricultural machinery and the actual generated power, the high efficiency range is re-matched in the generator MAP characteristic curve and the engine MAP characteristic curve to obtain the optimized engine speed and generator torque.

7. The power control method according to claim 5, characterized in that: The power control method further comprises: Obtaining the motor feedback power of the agricultural machinery during the braking process or the shutdown process of the operating motor; Determining a regenerative torque based on the motor regenerative power; and The torque of the engine is compensated by the feedback torque.

8. A power control device for agricultural machinery, characterized in that: include: a memory configured to store instructions; as well as A processor is configured to call the instructions from the memory and implement the power control method according to any one of claims 1 to 7 when executing the instructions.

9. An agricultural machine, characterized in that: Includes the power control device as claimed in claim 8.

10. A machine-readable storage medium, characterized in that: The machine-readable storage medium stores instructions, and the instructions are used to enable a machine to execute the power control method according to any one of claims 1 to 7.

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