Control method for extended-range hybrid excavator loader

Abstract

This invention provides a control method and system for a range-extended hybrid excavator loader. Based on the operating mode and the state of charge of the power battery, the operating condition of the power battery is determined. Combining the relationship between the optimal output power of the range extender and the power demand of the entire machine, the system controls the power supply ratio of the range extender and the power battery to the electrical equipment of the machine, or controls the power supply ratio of the range extender to the power battery and the electrical equipment of the machine. This ensures that the output power of the range extender, or the sum of the output power of the range extender and the output power of the power battery, always meets the power demand of the entire machine and keeps the range extender engine in the fuel-efficient range. This invention can adaptively adjust the output power of the range extender according to the state of charge of the power battery and the power demand of the entire machine to meet different operating conditions, ensuring that the range extender engine operates in the fuel-efficient range and that the excavator loader has sufficient power during operation.

Description

Technical Field

[0001] This invention belongs to the field of new energy engineering machinery control technology, and relates to a control method and system for a range-extended hybrid excavator loader. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] With the development of society and the economy, the demand for non-road mobile construction machinery is constantly increasing. Traditional construction machinery usually uses internal combustion engines as its power source. The air pollutants produced by internal combustion engines mainly include oxides such as carbon, nitrogen, and sulfur, as well as other harmful substances. The emission of these pollutants is positively correlated with fuel consumption. Therefore, the development of new energy products that can achieve energy conservation and emission reduction has become a top priority in the construction machinery field. Among new energy construction machinery, pure electric construction machinery can truly achieve "zero emissions" and "zero pollution." However, due to limitations in battery energy density, size, service life, and manufacturing costs, the single-cycle working time of pure electric construction machinery often cannot fully meet usage requirements. Range-extended hybrid power construction machinery solves the energy replenishment problem of pure electric construction machinery. At the same time, compared with traditional construction machinery, range-extended hybrid power construction machinery usually sets the engine to operate within the fuel economy range and can reduce engine output power fluctuations, thereby improving the fuel economy of the construction machinery.

[0004] Currently, the control strategies commonly used in range-extended hybrid electric vehicles (REEVs) include constant-temperature control, multi-point control, and power-following control. Constant-temperature control often results in the battery being in an overcharge / over-discharge state, which is detrimental to extending the battery's cycle life. Simultaneously, because the engine is required to provide power when the battery's state of charge (SOC) is low, if the engine displacement is small, the vehicle will frequently face the risk of insufficient power; therefore, a high-output engine is required. Multi-point control and power-following control strategies reduce fluctuations in battery SOC and prevent overcharging / over-discharging, but the engine's operating range is large, resulting in low energy utilization at idle.

[0005] For example, patent CN115626069A discloses a range extender control method for a forklift, a range-extended forklift, and a storage medium. This technology obtains a preset power to meet the charging needs of the battery by using the average power of the drive mechanism in a real-time work cycle and the historical power in previous work cycles. While the range extender can indeed meet the power requirements of construction machinery when operating at constant power under the preset power, the power battery is often in an overcharge / over-discharge state, which is detrimental to extending battery life. Furthermore, the range extender engine may not be operating within the fuel-efficient range under the preset power, leading to poor fuel economy and emissions. As another example, patent CN116160875B discloses a control method and device for a range extender system. This technology determines whether to activate the range extender based on the current vehicle status information and adjusts the range extender's power output according to the driver's driving intentions, making the power output responsive to the vehicle's power demand. Patent CN113879132B discloses a power control method for a vehicle range extender system, which can achieve power following control of the range extender power system based on real-time operating parameters and input power system parameters. Both of the above technologies can achieve power following control of the range extender, but they do not make the input power of the power battery change with the change of demand power. Therefore, the range extender engine may not be in the fuel economy range and cannot guarantee optimal economy and emissions. Summary of the Invention

[0006] To address the aforementioned problems, this invention proposes a range-extended hybrid excavator loader control method and system. This invention can adaptively adjust the output power of the range extender according to the state of charge of the power battery and the power demand of the entire machine to meet different working conditions, so that the range extender engine is in the fuel-efficient range and the excavator loader has sufficient power during operation.

[0007] According to some embodiments, the present invention adopts the following technical solution:

[0008] A control method for a range-extended hybrid excavator loader includes the following steps:

[0009] Determine the current operating mode of the range-extended hybrid excavator loader based on the status of the working motor and the travel motor;

[0010] Based on the operating mode and the state of charge of the power battery, the operating conditions of the power battery are determined. Combining the relationship between the optimal output power of the range extender and the power demand of the whole machine, the power supply ratio of the range extender and the power battery to the electrical equipment of the whole machine is controlled, or the power supply ratio of the range extender to the power battery and the electrical equipment of the whole machine is controlled, so that the output power of the range extender or the sum of the output power of the range extender and the output power of the power battery always meets the power demand of the whole machine and keeps the range extender engine in the fuel economy range.

[0011] As an alternative implementation, the specific process of determining the current working mode of the range-extended hybrid excavator loader based on the status of the working motor and the travel motor includes that if at least one of the working motor and the travel motor is running, the range-extended hybrid excavator loader is in working mode; otherwise, it is in standby mode.

[0012] As an alternative implementation method, in the operating mode, if the state of charge of the power battery is less than or equal to the minimum state of charge, the power battery is determined to be in the battery charging standby mode; if the state of charge of the power battery is greater than or equal to the maximum state of charge, the power battery is determined to be in the battery discharging standby mode; otherwise, the battery condition of the previous moment is maintained. If there is no previous moment in the operating mode, the power battery is in the battery charging standby mode.

[0013] As a further step, when the power battery is in standby charging mode, if the power demand of the whole machine is higher than the optimal output power of the range extender, the range extender is controlled to supply power to the electrical equipment of the whole machine separately, and the output power of the range extender is equal to the power demand of the whole machine.

[0014] If the power required for the operation of the whole machine is lower than the optimal output power of the range extender, and the optimal output power of the range extender is lower than the sum of the power required for the operation of the whole machine and the maximum input power of the power battery, then the range extender is controlled to supply power to both the electrical equipment of the whole machine and the power battery at the same time, and the output power of the range extender is kept equal to the optimal output power of the range extender.

[0015] If the sum of the total operating power demand of the machine and the maximum input power of the power battery is less than or equal to the optimal output power of the range extender, then the range extender will be controlled to supply power to both the electrical equipment of the machine and the power battery simultaneously, and the output power of the range extender will be equal to the sum of the total operating power demand of the machine and the maximum input power of the power battery.

[0016] Furthermore, when the power battery is in standby mode during operation, if the total operating power demand is greater than or equal to the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender are controlled to supply power to the electrical equipment of the whole machine at the same time, and the power battery is made to output at the maximum output power, and the output power of the range extender is made equal to the difference between the total operating power demand and the maximum output power of the power battery.

[0017] If the power demand of the whole machine is between the optimal output power of the range extender and the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender are controlled to supply power to the electrical equipment of the whole machine at the same time, and the output power of the range extender is kept equal to the optimal output power of the range extender, while the output power of the power battery follows the change of the power demand of the whole machine.

[0018] If the total operating power requirement is less than or equal to the optimal output power of the range extender, the range extender is controlled to supply power to the electrical equipment of the whole machine separately, and the output power of the range extender is equal to the total operating power requirement of the whole machine.

[0019] As an alternative implementation, in standby mode, if the state of charge of the power battery is less than or equal to the minimum state of charge, the power battery is determined to be in a battery charging standby mode; if the state of charge of the power battery is greater than or equal to the maximum state of charge, the power battery is determined to be in a battery discharging standby mode; otherwise, the battery condition of the previous moment is maintained. If there is no previous moment in standby mode, the power battery is in a battery charging standby mode.

[0020] Furthermore, when the power battery is in standby mode and is in a battery charging condition, if the power demand of the whole machine is higher than the optimal output power of the range extender, the range extender is controlled to supply power to the whole machine's electrical equipment separately, and the output power of the range extender is equal to the power demand of the whole machine.

[0021] If the total operating power demand is lower than the optimal output power of the range extender, and the optimal output power of the range extender is lower than the sum of the total operating power demand and the maximum input power of the power battery, then the range extender will be controlled to supply power to both the electrical equipment of the machine and the power battery at the same time, and the output power of the range extender will be kept equal to the optimal output power of the range extender, while the input power of the power battery will follow the changes in the total operating power demand.

[0022] If the sum of the total operating power demand of the machine and the maximum input power of the power battery is less than or equal to the optimal output power of the range extender, then the range extender will be controlled to supply power to both the electrical equipment of the machine and the power battery simultaneously, and the output power of the range extender will be equal to the sum of the total operating power demand of the machine and the maximum input power of the power battery.

[0023] Furthermore, when the power battery is in standby mode and is in standby condition, if the total operating power demand is greater than or equal to the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender are controlled to supply power to the electrical equipment of the whole machine at the same time, and the power battery is made to output at the maximum output power, and the output power of the range extender is made equal to the difference between the total operating power demand and the maximum output power of the power battery.

[0024] If the power demand of the whole machine is between the optimal output power of the range extender and the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender are controlled to supply power to the electrical equipment of the whole machine at the same time, and the output power of the range extender is kept equal to the optimal output power of the range extender, while the output power of the power battery follows the change of the power demand of the whole machine.

[0025] If the power required for the whole machine to operate is less than or equal to the optimal output power of the range extender, control the range extender to supply power to the electrical equipment of the whole machine separately, and make the output power of the range extender equal to the power required for the whole machine to operate.

[0026] If the power demand of the whole machine is less than or equal to the maximum output power of the power battery, the range extender will be shut down and the power battery will be used to supply power to the electrical equipment of the whole machine, and the whole machine will work in pure electric mode.

[0027] As an alternative implementation method, the specific process of determining the range extender output electric power curve includes finding the corresponding speed and torque of several points on the engine fuel economy curve, setting the engine speed and the electromagnetic resistance torque of the generator according to these speeds and torques, obtaining several range extender output electric power points at different speeds, and then connecting adjacent points to obtain the range extender output electric power curve.

[0028] As an alternative implementation method, the specific process of determining the optimal output electric power of the range extender includes finding the speed and torque corresponding to the most fuel-efficient point on the engine fuel economy curve, and then setting the engine speed and the electromagnetic resistance torque of the generator according to the speed and torque.

[0029] As an alternative implementation, the process of controlling the range extender output power to be equal to the sum of the total operating power demand of the machine and the maximum input power of the power battery includes finding the range extender output power and its corresponding speed on the range extender output power curve corresponding to the sum of the total operating power demand of the machine and the maximum input power of the power battery; finding the corresponding torque on the engine fuel economy curve based on the speed; and setting the engine speed and the electromagnetic resistance torque of the generator based on the speed and torque, respectively.

[0030] As an alternative implementation method, the specific control process of controlling the range extender output power to be equal to the difference between the total operating power demand and the maximum output power of the power battery includes finding the range extender output power and its corresponding speed on the range extender output power curve corresponding to the difference between the total operating power demand and the maximum output power of the power battery; finding the corresponding torque on the engine fuel economy curve based on the speed; and setting the engine speed and the generator electromagnetic resistance torque based on the speed and torque, respectively.

[0031] A range-extended hybrid excavator loader control system includes:

[0032] The working mode determination module is configured to determine the current working mode of the range-extended hybrid excavator loader based on the status of the working motor and the travel motor.

[0033] The battery condition determination module is configured to determine the operating condition of the power battery based on the working mode and the state of charge of the power battery.

[0034] The control module is configured to combine the relationship between the optimal output power of the range extender and the power demand of the whole machine, control the power supply ratio of the range extender and the power battery to the electrical equipment of the whole machine, or control the power supply ratio of the range extender to the power battery and the electrical equipment of the whole machine, so that the output power of the range extender or the sum of the output power of the range extender and the output power of the power battery always meets the power demand of the whole machine, and keeps the range extender engine in the fuel economy range.

[0035] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0036] This invention innovatively proposes a control method for a range-extended hybrid excavator loader. This control method can adaptively adjust the output power of the range extender according to the power battery SOC and the overall machine power demand to meet different working conditions, ensuring that the excavator loader has sufficient power during operation, reducing the power battery from being in an overcharge and discharge state frequently, and helping to extend battery life.

[0037] This invention innovatively proposes a control method for a range-extended hybrid excavator loader. This control method allows the input power of the power battery to change with the power demand, and the output power of the range extender always meets the power demand of the whole machine. Moreover, the difference between the output power of the range extender and the optimal output power of the range extender is less than the set value, ensuring that the engine in the range extender always works at the fuel economy point or fuel economy curve, which can save fuel to the greatest extent and reduce emissions.

[0038] This invention innovatively proposes a range-extended hybrid excavator loader range-extended power control method. This method determines whether the excavator loader is in operation or standby mode based on the working status of the travel motor and the working motor. When the excavator loader is in operation, the range extender is always kept on through the above control method, and the power battery mainly plays the role of peak shaving and valley filling, thus keeping it in a shallow charge and discharge state for a long time, which is conducive to extending the cycle life of the power battery. When the excavator loader is in standby mode and the battery has sufficient power, the range extender is kept off to avoid the engine running at idle speed and improve the overall energy utilization rate of the machine.

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0040] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0041] Figure 1 This is a schematic diagram of an engine fuel economy curve and the point of optimal fuel economy in one embodiment.

[0042] Figure 2 An example of a range extender's output power curve and optimal output power P. e Schematic diagram;

[0043] Figure 3 This is a schematic diagram of the power system architecture of a range-extended hybrid excavator loader according to one embodiment.

[0044] Figure 4 This is a flowchart of a control method according to one embodiment;

[0045] Figure 5 yes Figure 4 Detailed flowchart of the control method in the process;

[0046] Figure 6 yes Figure 4 A detailed flowchart of the control method in the process. Detailed Implementation

[0047] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0048] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0049] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0050] Example 1

[0051] The control method of range-extended hybrid excavator loader is based on the working status of the travel motor and the working motor. The excavator loader can be divided into two working modes: operation and standby. In each working mode, the power system has two working conditions: battery charging and battery discharging.

[0052] The VCU (Vehicle Control Unit) first determines the operating mode and standby mode of the machine by detecting the operating status of the working motor and the drive motor.

[0053] If at least one of the working motor and the travel motor is running, the entire machine is in operating mode.

[0054] If neither the working motor nor the driving motor is running, the entire machine will be in standby mode.

[0055] The following is combined Figures 4-6 The control strategies for each mode are explained in detail.

[0056] 1. Work Mode

[0057] In this mode, the VCU (or other control modules in other embodiments, the same below) first determines whether the power system is in a battery charging or discharging state by detecting the value of the SOC of the power battery.

[0058] If SOC≤SOC min The power battery has a low charge level, and the power system is in standby charging mode.

[0059] If SOC ≥ SOC max The power battery has a high charge level, and the power system adopts the battery standby discharge condition.

[0060] If SOC min <SOC<SOC max ,

[0061] If the previous moment was a battery charging standby state, the power system will still maintain the battery charging standby state;

[0062] If the previous moment was a battery standby mode, the power system will remain in the battery standby mode.

[0063] If the machine has just entered the working mode, the power system will be in the battery charging standby mode.

[0064] (1) Battery standby charging condition: Under this condition, the power battery only exists in two states: waiting and charging; the range extender always maintains the power generation state.

[0065] When P req ≥P e At that time, the total power required for the operation of the machine is P req Higher than the optimal output power P of the range extender e If the power battery is charged at the same time, the range extender's output power P will be affected. v This further increases the fuel consumption rate, resulting in a rate even higher than the engine's most fuel-efficient point. Therefore, at this point, the VCU (Vehicle Control Unit) controls the range extender to supply power to the electrical equipment of the entire machine independently, and causes the range extender to output electrical power P. v Real-time equals the total power demand P of the machine. req To make the range extender output electrical power P v Real-time equals the total power demand P of the machine. req The specific control method is as follows: First, find the power P corresponding to the overall operating demand of the machine on the range extender output power curve. req The range extender output power Pv The engine speed and its corresponding rotational speed are determined, and then the corresponding torque is found on the engine's fuel economy curve based on this speed. The engine speed and the generator's electromagnetic resistance torque are then set according to these parameters. This ensures the engine always operates along the fuel economy curve, maintaining a low fuel consumption rate.

[0066] When P req <P e <P req +P bat_in_max At that time, the total power required for the operation of the machine is P req Below the optimal output power P of the range extender e Furthermore, when the engine operates at its most fuel-efficient point, the range extender outputs electrical power P. v Subtract the total power requirement P req Afterwards, the remaining power did not exceed the maximum input power P of the power battery. bat_in_max The remaining power can be allocated to charge the power battery. Therefore, at this time, the VCU (Vehicle Control Unit) controls the range extender to simultaneously supply power to both the electrical equipment and the power battery, and causes the range extender to output electrical power P. v Equal to the optimal output power P of the range extender e This is also equal to the total power requirement P of the entire machine. req With the power battery input power P bat_in The sum of these, the input power P of the power battery bat_in Power P required for overall machine operation req Changes occur, causing the range extender's output electrical power P to change. v Real-time equals engine fuel economy point power P e The specific control method is as follows: Find the engine speed and torque corresponding to the most fuel-efficient point on the engine's fuel economy curve. Then, set the engine speed and the generator's electromagnetic resistance torque according to these values. This ensures the engine always operates at its most fuel-efficient point, maintaining the lowest fuel consumption.

[0067] When P req +P bat_in_max ≤P e At that time, the total power required for the operation of the machine is P req Below the optimal output power P of the range extender e And even if the power battery input power P bat_in When the maximum range extender output power P is reached, v Still below the optimal output power P of the range extender e This results in an engine fuel consumption rate higher than the engine's most fuel-efficient point. Therefore, at this time, the VCU (Vehicle Control Unit) controls the range extender to simultaneously supply power to the electrical equipment and the battery, and increases the range extender's output power P.v Real-time equals the total power demand P of the machine. req With the maximum input power P of the power battery bat_in The sum of these. This causes the range extender to output electrical power P. v Real-time equals the total power demand P of the machine. req With the maximum input power P of the power battery bat_in_max The specific control method for the sum is as follows: First, find the power P corresponding to the overall operating demand of the machine on the range extender output power curve. req With the maximum input power P of the power battery bat_in_max The sum of the range extender output power P v The engine speed and its corresponding rotational speed are determined, and then the corresponding torque is found on the engine's fuel economy curve based on this speed. The engine speed and the generator's electromagnetic resistance torque are then set according to these parameters. This ensures the engine always operates along the fuel economy curve, maintaining a low fuel consumption rate.

[0068] (2) Battery waiting to discharge condition: Under this condition, the power battery only exists in two states: waiting and discharging; the range extender always maintains the power generation state.

[0069] When P req ≥P e +P bat_out_max At that time, the total power required for the operation of the machine is P req Higher than the optimal output power P of the range extender e And even if the power battery outputs electrical power P bat_out When the maximum range extender output power P is reached, v Still higher than the optimal output power P of the range extender e Therefore, at this time, the VCU (Vehicle Control Unit) controls the power battery and range extender to simultaneously supply power to the electrical equipment of the entire machine, and enables the power battery to output maximum power P. bat_out_max Output, and make the range extender output power P v Real-time equals the total power demand P of the machine. req With the maximum output power P of the power battery bat_out_max The difference causes the range extender's output power P to... v Real-time equals the total power demand P of the machine. req With the maximum output power P of the power battery bat_out_max The specific control method for the difference is as follows: First, find the power P corresponding to the overall machine's operating demand on the range extender's output power curve. req With the maximum output power P of the power battery bat_out_max The difference in range extender output power P vThe engine speed and its corresponding rotational speed are determined, and then the corresponding torque is found on the engine's fuel economy curve based on this speed. The engine speed and the generator's electromagnetic resistance torque are then set according to these parameters. This ensures the engine always operates along the fuel economy curve, maintaining a low fuel consumption rate.

[0070] When P e <P req <P e +P bat_out_max At that time, the total power required for the operation of the machine is P req Higher than the optimal output power P of the range extender e Furthermore, when the engine operates at its most fuel-efficient point, the total power demand P of the entire machine is [not specified]. req Subtract the range extender output power P v Afterwards, the remaining power did not exceed the maximum output power P of the power battery. bat_out_max The power battery can be discharged to compensate for the insufficient output power of the range extender. Therefore, at this time, the VCU (Vehicle Control Unit) controls both the power battery and the range extender to simultaneously supply power to the electrical equipment of the entire machine, and ensures that the range extender outputs power P. v Equal to the optimal output power P of the range extender e This is also equal to the total power requirement P of the entire machine. req With the power battery output power P bat_out The difference is in the output power P of the power battery. bat_out Power P required for overall machine operation req change.

[0071] When P req ≤P e At that time, the total power required for the operation of the machine is P req Below the optimal output power P of the range extender e If the power battery is discharged at the same time, the range extender's output power P will be affected. v This further reduces fuel consumption, resulting in an engine fuel consumption rate even lower than the engine's most fuel-efficient point. Therefore, at this point, the VCU (Vehicle Control Unit) controls the range extender to supply power to the entire machine's electrical equipment independently, and enables the range extender to output electrical power P. v Real-time equals the total power demand P of the machine. req .

[0072] 2. Standby mode

[0073] In this mode, the VCU (Vehicle Control Unit) first determines whether the power system is in a battery charging or discharging state by detecting the state of charge (SOC) value of the power battery.

[0074] If SOC≤SOC min The power battery has a low charge level, and the power system is in standby charging mode.

[0075] If SOC ≥ SOC max The power battery has a high charge level, and the power system operates under a battery discharge standby condition.

[0076] If SOC min <SOC<SOC mxx ,

[0077] If the previous moment was a battery charging standby state, the power system will still maintain the battery charging standby state;

[0078] If the previous moment was a battery standby mode, the power system will remain in the battery standby mode.

[0079] If the device has just entered standby mode, the power system will operate under battery charging conditions.

[0080] (1) Battery standby charging condition: Under this condition, the power battery only exists in two states: waiting and charging; the range extender always maintains the power generation state.

[0081] When P req ≥P e At that time, the total power required for the operation of the machine is P req Higher than the optimal output power P of the range extender e If the power battery is charged at the same time, the range extender's output power P will be affected. v This further increases the fuel consumption rate, resulting in a rate even higher than the engine's most fuel-efficient point. Therefore, at this point, the VCU (Vehicle Control Unit) controls the range extender to supply power to the electrical equipment of the entire machine independently, and causes the range extender to output electrical power P. v Real-time equals the total power demand P of the machine. req .

[0082] When P req <P e <P req +P bat_in_max At that time, the total power required for the operation of the machine is P req Below the optimal output power P of the range extender e Furthermore, when the engine operates at its most fuel-efficient point, the range extender outputs electrical power P. v Subtract the total power requirement P req Afterwards, the remaining power did not exceed the maximum input power P of the power battery. bat_in_max The remaining power can be allocated to charge the power battery. Therefore, at this time, the VCU (Vehicle Control Unit) controls the range extender to simultaneously supply power to both the electrical equipment and the power battery, and causes the range extender to output electrical power P. v Equal to the optimal output power P of the range extender e This is also equal to the total power requirement P of the entire machine. req With the power battery input power Pbat_in The sum of these, the input power P of the power battery bat_in Power P required for overall machine operation req change.

[0083] When P req +P bat_in_max ≤P e At that time, the total power required for the operation of the machine is P req Below the optimal output power P of the range extender e And even if the power battery input power P bat_in When the maximum range extender output power P is reached, v Still below the optimal output power P of the range extender e This results in an engine fuel consumption rate higher than the engine's most fuel-efficient point. Therefore, at this time, the VCU (Vehicle Control Unit) controls the range extender to simultaneously supply power to the electrical equipment and the battery, and increases the range extender's output power P. v Real-time equals the total power demand P of the machine. req With the maximum input power P of the power battery bat_in sum.

[0084] (2) Battery waiting to discharge condition: Under this condition, the power battery only exists in two states: waiting and discharging; the range extender exists in two states: shut down and generating.

[0085] When P req ≥P e +P bat_out_max At that time, the total power required for the operation of the machine is P req Higher than the optimal output power P of the range extender e And even if the power battery outputs electrical power P bat_out When the maximum range extender output power P is reached, v Still higher than the optimal output power P of the range extender e Therefore, at this time, the VCU (Vehicle Control Unit) controls the power battery and range extender to simultaneously supply power to the electrical equipment of the entire machine, and enables the power battery to output maximum power P. bat_out_max Output, and make the range extender output power P v Real-time equals the total power demand P of the machine. req With the maximum output power P of the power battery bat_out_max difference.

[0086] When P e <P req <P e +P bat_out_max At that time, the total power required for the operation of the machine is P req Higher than the optimal output power P of the range extender e Furthermore, when the engine operates at its most fuel-efficient point, the total power demand P of the entire machine is [not specified].req Subtract the range extender output power P v Afterwards, the remaining power did not exceed the maximum output power P of the power battery. bat_out_max The power battery can be discharged to compensate for the insufficient output power of the range extender. Therefore, at this time, the VCU (Vehicle Control Unit) controls both the power battery and the range extender to simultaneously supply power to the electrical equipment of the entire machine, and ensures that the range extender outputs power P. v Equal to the optimal output power P of the range extender e This is also equal to the total power requirement P of the entire machine. req With the power battery output power P bat_out The difference is in the output power P of the power battery. bat_out Power P required for overall machine operation req change.

[0087] When P req ≤P e At that time, the total power required for the operation of the machine is P req Below the optimal output power P of the range extender e If the power battery is discharged at the same time, the range extender's output power P will be affected. v Further reductions result in an engine fuel consumption rate even lower than the engine's most fuel-efficient point. However, due to the overall engine's operating power requirement P... req Higher than the maximum output power P of the power battery bat_out_max If the range extender is turned off and the power battery alone provides power, it cannot meet the overall operating requirements of the machine. Therefore, at this time, the VCU (Vehicle Control Unit) controls the range extender to supply power to the electrical equipment of the whole machine, and makes the range extender output power P. v Real-time equals the total power demand P of the machine. req .

[0088] When P req ≤P bat_out_max At that time, the total power required for the operation of the machine is P req Lower than the maximum output power P of the power battery bat_out_max Therefore, at this time, the VCU controller shuts down the range extender and controls the power battery to supply power to the electrical equipment of the whole machine, and the whole machine operates in pure electric mode.

[0089] It should be noted that the above control method requires the following input parameters to be determined in advance:

[0090] i. Maximum input power of the power battery P bat_in_max and maximum output power P bat_out_max ;

[0091] ii. Maximum State of Charge (SOC) of Power Batteries max and minimum SOC min ;

[0092] iii. Engine fuel economy curve and the fuel-efficient point on the curve, such as Figure 1 As shown;

[0093] iv. The range extender output power curve corresponding to the engine fuel economy curve, and the optimal output power P of the range extender corresponding to the point of greatest fuel economy on the curve. e ,like Figure 2 As shown.

[0094] The parameters in the above four aspects are known data, which are pre-inputted and stored in the VCU or control module of the whole machine controller.

[0095] In addition, the above control process also needs to acquire operating status parameters, which are described in detail below:

[0096] like Figure 3 As shown, the electrical equipment on a range-extended hybrid excavator loader consists of three parts: a working motor, a travel motor, and other electrical equipment. The sum of the power of these three parts equals the total operating power P required by the machine. req After the excavator loader starts, the VCU (Vehicle Control Unit) monitors the machine's operating power requirement P in real time. req Range extender output power P v Power battery input power P bat_in Or output power P bat_out The power battery's state of charge (SOC) is controlled, and the range extender's output power (P) is also controlled. v With the power battery output power P bat_out The sum or range extender output power P v With the power battery input power P bat_in The difference in time is equal to the total power demand P of the machine. req This means that the range extender and the power battery follow the power requirements of the entire machine.

[0097] Example 2

[0098] A whole machine controller or control device for executing the control method of Embodiment 1.

[0099] Example 3

[0100] A range-extended hybrid excavator loader control system includes:

[0101] The working mode determination module is configured to determine the current working mode of the range-extended hybrid excavator loader based on the status of the working motor and the travel motor.

[0102] The battery condition determination module is configured to determine the operating condition of the power battery based on the working mode and the state of charge of the power battery.

[0103] The control module is configured to combine the relationship between the optimal output power of the range extender and the power demand of the entire machine, and control the power supply ratio of the range extender and the power battery to the electrical equipment of the entire machine, or control the power supply ratio of the range extender to the power battery and the electrical equipment of the entire machine, so that the output power of the range extender, or the sum of the output power of the range extender and the output power of the power battery, always meets the power demand of the entire machine, and keeps the range extender engine in the fuel economy range. Those skilled in the art will understand that embodiments of the present invention can be provided as methods, systems, or computer program products. Therefore, the present invention can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0104] This invention is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0105] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0106] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0107] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

[0108] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. A control method for a range-extended hybrid excavator loader, characterized in that, Includes the following steps: The current working mode of the range-extended hybrid excavator loader is determined based on the status of the working motor and the travel motor. Specifically, if at least one of the working motor and the travel motor is running, the range-extended hybrid excavator loader is in working mode; otherwise, it is in standby mode. In working mode, the range extender always remains in power generation mode. Based on the working mode and the state of charge of the power battery, the working condition of the power battery is determined. Combining the relationship between the optimal output power of the range extender and the power demand of the whole machine, the power supply ratio of the range extender and the power battery to the electrical equipment of the whole machine is controlled, or the power supply ratio of the range extender to the power battery and the electrical equipment of the whole machine is controlled, so that the output power of the range extender or the sum of the output power of the range extender and the output power of the power battery always meets the power demand of the whole machine and keeps the range extender engine in the fuel economy range. When the power battery is in standby charging mode, if the power demand of the whole machine is higher than the optimal output power of the range extender, the range extender is controlled to supply power to the electrical equipment of the whole machine separately, and the output power of the range extender is equal to the power demand of the whole machine. If the power required for the operation of the whole machine is lower than the optimal output power of the range extender, and the optimal output power of the range extender is lower than the sum of the power required for the operation of the whole machine and the maximum input power of the power battery, then the range extender is controlled to supply power to both the electrical equipment of the whole machine and the power battery at the same time, and the output power of the range extender is kept equal to the optimal output power of the range extender. If the sum of the total operating power demand of the machine and the maximum input power of the power battery is less than or equal to the optimal output power of the range extender, then the range extender will be controlled to supply power to both the electrical equipment of the machine and the power battery simultaneously, and the output power of the range extender will be equal to the sum of the total operating power demand of the machine and the maximum input power of the power battery.

2. The control method for a range-extended hybrid excavator loader as described in claim 1, characterized in that, In the operating mode, if the state of charge of the power battery is less than or equal to the minimum state of charge, the power battery is determined to be in the battery charging standby mode; if the state of charge of the power battery is greater than or equal to the maximum state of charge, the power battery is determined to be in the battery discharging standby mode; otherwise, the battery condition of the previous moment is maintained. If there is no previous moment in the operating mode, the power battery is in the battery charging standby mode.

3. The control method for a range-extended hybrid excavator loader as described in claim 2, characterized in that, When the power battery is in standby mode, if the total operating power demand is greater than or equal to the sum of the range extender's optimal output power and the power battery's maximum output power, the power battery and the range extender will simultaneously supply power to the equipment of the whole machine, and the power battery will output at its maximum output power, and the range extender's output power will be equal to the difference between the total operating power demand and the power battery's maximum output power. If the power demand of the whole machine is between the optimal output power of the range extender and the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender are controlled to supply power to the electrical equipment of the whole machine at the same time, and the output power of the range extender is kept equal to the optimal output power of the range extender, while the output power of the power battery follows the change of the power demand of the whole machine. If the total operating power requirement is less than or equal to the optimal output power of the range extender, the range extender is controlled to supply power to the electrical equipment of the whole machine separately, and the output power of the range extender is equal to the total operating power requirement of the whole machine.

4. The control method for a range-extended hybrid excavator loader as described in claim 1, characterized in that, In standby mode, if the state of charge of the power battery is less than or equal to the minimum state of charge, the power battery is determined to be in standby charging mode; if the state of charge of the power battery is greater than or equal to the maximum state of charge, the power battery is determined to be in standby discharging mode; otherwise, the battery condition of the previous moment is maintained. If there is no previous moment in standby mode, the power battery is in standby charging mode.

5. The control method for a range-extended hybrid excavator loader as described in claim 4, characterized in that, When the power battery is in standby mode and the battery is in charge-ready condition, if the power demand of the whole machine is higher than the optimal output power of the range extender, the range extender is controlled to supply power to the electrical equipment of the whole machine separately, and the output power of the range extender is equal to the power demand of the whole machine. If the total operating power demand is lower than the optimal output power of the range extender, and the optimal output power of the range extender is lower than the sum of the total operating power demand and the maximum input power of the power battery, then the range extender will be controlled to supply power to both the electrical equipment of the machine and the power battery at the same time, and the output power of the range extender will be kept equal to the optimal output power of the range extender, while the input power of the power battery will follow the changes in the total operating power demand. If the sum of the total operating power demand of the machine and the maximum input power of the power battery is less than or equal to the optimal output power of the range extender, then the range extender will be controlled to supply power to both the electrical equipment of the machine and the power battery simultaneously, and the output power of the range extender will be equal to the sum of the total operating power demand of the machine and the maximum input power of the power battery.

6. The control method for a range-extended hybrid excavator loader as described in claim 4, characterized in that, When in standby mode, if the power battery is in standby mode and the total power demand of the machine is greater than or equal to the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender will be controlled to supply power to the electrical equipment of the machine at the same time, and the power battery will be made to output at the maximum output power, and the output power of the range extender will be equal to the difference between the total power demand of the machine and the maximum output power of the power battery. If the power demand of the whole machine is between the optimal output power of the range extender and the sum of the optimal output power of the range extender and the maximum output power of the power battery, the power battery and the range extender are controlled to supply power to the electrical equipment of the whole machine at the same time, and the output power of the range extender is kept equal to the optimal output power of the range extender, while the output power of the power battery follows the change of the power demand of the whole machine. If the power required for the whole machine to operate is less than or equal to the optimal output power of the range extender, control the range extender to supply power to the electrical equipment of the whole machine separately, and make the output power of the range extender equal to the power required for the whole machine to operate. If the power demand of the whole machine is less than or equal to the maximum output power of the power battery, the range extender will be shut down and the power battery will be used to supply power to the electrical equipment of the whole machine, and the whole machine will work in pure electric mode.

7. A control method for a range-extended hybrid excavator loader as described in claims 1, 3, 5, or 6, characterized in that, The specific process of determining the range extender output power curve includes finding the corresponding speed and torque of several points on the engine fuel economy curve, setting the engine speed and the electromagnetic resistance torque of the generator according to these speeds and torques, obtaining several range extender output power points at different speeds, and then connecting adjacent points to obtain the range extender output power curve.

8. A control method for a range-extended hybrid excavator loader as described in claims 1, 3, 5, or 6, characterized in that, The specific process of determining the optimal output electric power of the range extender includes finding the speed and torque corresponding to the most fuel-efficient point on the engine's fuel economy curve, and then setting the engine speed and the electromagnetic resistance torque of the generator based on the speed and torque.

9. A control method for a range-extended hybrid excavator loader as described in claims 1, 3, 5, or 6, characterized in that, The process of controlling the range extender output power to equal the sum of the total operating power demand and the maximum input power of the power battery includes finding the range extender output power and its corresponding speed on the range extender output power curve corresponding to the sum of the total operating power demand and the maximum input power of the power battery; finding the corresponding torque on the engine fuel economy curve based on the speed; and setting the engine speed and the generator electromagnetic resistance torque based on the speed and torque, respectively.

10. A control method for a range-extended hybrid excavator loader as described in claims 1, 3, 5, or 6, characterized in that, The specific control process for controlling the range extender's output power to equal the difference between the total operating power demand and the maximum output power of the power battery includes: finding the range extender's output power and its corresponding speed on the range extender's output power curve corresponding to the difference between the total operating power demand and the maximum output power of the power battery; finding the corresponding torque on the engine's fuel economy curve based on this speed; and setting the engine speed and the generator's electromagnetic resistance torque based on this speed and torque, respectively.

11. A range-extended hybrid excavator loader control system employing the method described in claim 1, characterized in that, include: The working mode determination module is configured to determine the current working mode of the range-extended hybrid excavator loader based on the status of the working motor and the travel motor. The battery condition determination module is configured to determine the operating condition of the power battery based on the working mode and the state of charge of the power battery. The control module is configured to combine the relationship between the optimal output power of the range extender and the power demand of the whole machine, control the power supply ratio of the range extender and the power battery to the electrical equipment of the whole machine, or control the power supply ratio of the range extender to the power battery and the electrical equipment of the whole machine, so that the output power of the range extender or the sum of the output power of the range extender and the output power of the power battery always meets the power demand of the whole machine, and keeps the range extender engine in the fuel economy range.

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