Control method, controller, system, excavator, storage medium and program product

Abstract

This disclosure provides a control method, controller, system, excavator, storage medium, and program product. The control method includes: obtaining the real-time power of the slewing motor, the maximum allowable charging power of the battery, and the maximum allowable discharging power of the battery; calculating the maximum allowable effective discharge power of the battery based on the maximum allowable discharge power, and calculating the maximum allowable effective charging power of the battery based on the maximum allowable charging power; controlling the ISG motor to enter a power compensation mode when the real-time power of the slewing motor is greater than the maximum allowable effective discharge power of the battery and the maximum allowable effective discharge power of the battery is greater than 0; and controlling the ISG motor to enter a power consumption mode when the real-time power of the slewing motor is less than the maximum allowable effective charging power of the battery and the maximum allowable effective charging power of the battery is less than 0.

Description

Technical Field

[0001] This disclosure relates to the field of new energy construction machinery, and in particular to a control method, controller, system, excavator, storage medium, and program product. Background Technology

[0002] Against the backdrop of energy conservation and emission reduction, the green transformation of the construction machinery industry is accelerating. Hybrid technology, due to its advantages such as low operating costs, no range anxiety, energy saving and emission reduction, and strong power, is being widely used in construction machinery products. Hybrid excavators equipped with electric slewing mechanisms use a slewing motor to drive the platform's rotation, accelerating through electric braking and recovering braking energy. The ISG (Integrated Starter / Generator) motor can generate electricity to maintain the battery's SOC (State of Charge) balance or power the engine, resulting in higher energy efficiency and power for the entire machine. Here, SOC refers to the remaining battery capacity.

[0003] However, since the power battery, rotary motor, and ISG motor are all high-voltage power components, the rotary motor requires a high peak power when starting and stopping the rotary motion, which can easily cause overcharging or over-discharging of the battery. Summary of the Invention

[0004] One technical problem addressed by this disclosure is that, in related technologies, hybrid excavators are prone to battery overcharging or over-discharging issues.

[0005] According to one aspect of this disclosure, a control method for a hybrid excavator is provided, comprising: obtaining the real-time power of a slewing motor, the maximum allowable charging power of a battery, and the maximum allowable discharging power of a battery; calculating the maximum allowable effective discharge power of the battery based on the maximum allowable discharge power of the battery, and calculating the maximum allowable effective charging power of the battery based on the maximum allowable charging power of the battery; when the real-time power of the slewing motor is greater than the maximum allowable effective discharge power of the battery and the maximum allowable effective discharge power of the battery is greater than 0, controlling an integrated intelligent starter generator (ISG) motor to enter a power compensation mode, so that the ISG motor performs power generation operation to compensate for the power required by the slewing motor; and when the real-time power of the slewing motor is less than the maximum allowable effective charging power of the battery and the maximum allowable effective charging power of the battery is less than 0, controlling the ISG motor to enter a power consumption mode, so that the ISG motor performs drive operation to consume the excess power of the slewing motor.

[0006] In some embodiments, the maximum allowable effective discharge power P′ of the battery mDis for

[0007] P′ mDis =P mDis -P dcdc -P res ,

[0008] Among them, P mDis P is the maximum allowable discharge power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

[0009] In some embodiments, the battery allows a maximum effective charging power P′ mChg for

[0010] P′ mChg =P mChg -P dcdc +P res ,

[0011] Among them, P mChg P is the maximum allowable charging power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

[0012] In some embodiments, the control method further includes: determining whether the state of charge (SOC) of the battery is less than a SOC threshold when the real-time power of the rotary motor is less than or equal to the maximum allowable effective discharge power of the battery and the real-time power of the rotary motor is greater than 0, or when the real-time power of the rotary motor is greater than or equal to the maximum allowable effective charging power of the battery and the real-time power of the rotary motor is less than 0; controlling the ISG motor to enter a forced power generation mode when the SOC of the battery is less than the SOC threshold, so that the ISG motor performs power generation operation to replenish the battery's charge; and controlling the operation of the ISG motor according to the real-time power of the hydraulic pump when the SOC of the battery is greater than or equal to the SOC threshold.

[0013] In some embodiments, controlling the operation of the ISG motor based on the real-time power of the hydraulic pump includes: when the real-time power of the hydraulic pump is greater than the optimal power limit of the engine, controlling the ISG motor to enter a drive assist mode so that the ISG motor assists the operation of the hydraulic pump; and when the real-time power of the hydraulic pump is less than or equal to the optimal power limit of the engine, controlling the ISG motor to enter a zero-power follow mode so that the ISG motor follows the engine in a zero-power manner.

[0014] In some embodiments, the control method further includes: calculating the target power of the ISG motor according to different modes in which the ISG motor is located; and calculating the initial target torque of the ISG motor according to the target power of the ISG motor.

[0015] In some embodiments, calculating the target power of the ISG motor based on different modes in which the ISG motor is located includes: when the ISG motor is in the power compensation mode, the target power P of the ISG motor is calculated. T-ISG for

[0016] P T-ISG =P S -(P mDis -P dcdc -P res ),

[0017] Among them, P S P represents the real-time power of the rotary motor. mDis P is the maximum allowable discharge power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

[0018] In some embodiments, calculating the target power of the ISG motor based on different modes in which the ISG motor is located includes: when the ISG motor is in the power consumption mode, the target power P of the ISG motor is calculated. T-ISG for

[0019] P T-ISG =P S -(P mChg -P dcdc +P res ),

[0020] Among them, P S P represents the real-time power of the rotary motor. mChg P is the maximum allowable charging power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

[0021] In some embodiments, calculating the target power of the ISG motor based on different modes in which the ISG motor is located includes: when the ISG motor is in the forced generation mode, the target power P of the ISG motor is calculated. T-ISG for

[0022] P T-ISG =P Chg ,

[0023] Among them, P Chg This is a preset constant value.

[0024] In some embodiments, calculating the target power of the ISG motor based on the different modes in which the ISG motor is located includes: when the ISG motor is in the drive assist mode, the target power P of the ISG motor is calculated. T-ISG for

[0025] P T-ISG =P P -P opt ,

[0026] Among them, P P P is the real-time power of the hydraulic pump. opt This represents the optimal upper limit of the engine's power output.

[0027] In some embodiments, calculating the target power of the ISG motor based on different modes in which the ISG motor is in includes: when the ISG motor is in zero-power follower mode, the target power P of the ISG motor is calculated. T-ISG It is 0.

[0028] In some embodiments, the initial target torque T of the ISG motor T-ISG for

[0029] T T-ISG =P T-ISG *9550 / n ISG ,

[0030] Among them, P T-ISG n is the target power of the ISG motor. ISG The real-time rotational speed of the ISG motor is given.

[0031] In some embodiments, the control method further includes: when the ISG motor is in the power compensation mode, the power consumption mode, the forced generation mode, or the drive assist mode, correcting the initial target torque of the ISG motor using a fuzzy control algorithm to obtain the corrected target torque of the ISG motor; and controlling the operation of the ISG motor according to the corrected target torque of the ISG motor.

[0032] In some embodiments, the initial target torque of the ISG motor is corrected using a fuzzy control algorithm, including: obtaining a target torque correction amount for the ISG motor based on the engine's target speed and speed error using the fuzzy control algorithm; and obtaining the corrected target torque T of the ISG motor based on the target torque correction amount. ISG ,

[0033] T ISG =min(T) T-ISG +ΔT,T ISG-max ),

[0034] Among them, T T-ISG Let T be the initial target torque of the ISG motor, and ΔT be the target torque correction amount of the ISG motor. ISG-max This represents the maximum allowable torque of the ISG motor at the current speed.

[0035] In some embodiments, the control method further includes: when the ISG motor is not in the power consumption mode, controlling the hydraulic pump to maintain the current output pressure; when the ISG motor is in the power consumption mode, determining whether the real-time power of the hydraulic pump is greater than the target power of the ISG motor; when the real-time power of the hydraulic pump is greater than or equal to the target power of the ISG motor, controlling the hydraulic pump to maintain the current output pressure; and when the real-time power of the hydraulic pump is less than the target power of the ISG motor, controlling the increase of the output pressure of the hydraulic pump.

[0036] In some embodiments, controlling the increase in the output pressure of the hydraulic pump includes: calculating the pressure increment ΔP of the hydraulic pump's output pressure.

[0037]

[0038] Among them, P T-ISG P is the target power of the ISG motor. P Let η be the real-time power of the hydraulic pump, Q be the flow rate of the hydraulic pump, and η be the efficiency of the hydraulic pump.

[0039] In some embodiments, the control method further includes: determining a target speed of the hydraulic pump; calculating a corresponding throttle opening based on the target speed of the hydraulic pump; and controlling the operation of the engine based on the throttle opening.

[0040] In some embodiments, the control method further includes: determining a target speed of the rotary motor; calculating a target torque of the rotary motor based on the target speed of the rotary motor and the actual speed of the rotary motor collected in real time; and controlling the operation of the rotary motor based on the target torque of the rotary motor.

[0041] In some embodiments, the target torque T of the rotary motor s for

[0042] T s =min(T) i ,T s-max ),

[0043] in,

[0044] Where e(t) is the target speed n of the rotary motor. s The actual rotational speed n of the rotary motor was collected in real time. s-act The real-time difference between them, K p K is the proportionality coefficient. i K is the integral coefficient. d T is the differential coefficient. s-max This is the maximum allowable real-time torque for the rotary motor.

[0045] According to another aspect of this disclosure, a vehicle controller is provided, comprising: a memory; and a processor coupled to the memory, the processor being configured to execute the control method as described above based on instructions stored in the memory.

[0046] According to another aspect of this disclosure, a control system for a hybrid excavator is provided, comprising: a vehicle controller as described above.

[0047] In some embodiments, the control system further includes: a joystick, a driving pedal, and a gear shifting device, each electrically connected to the vehicle controller; a battery management system, electrically connected to the vehicle controller; a battery, electrically connected to the battery management system; a DC-DC converter, electrically connected to the battery; a rotary motor controller, electrically connected to both the battery and the vehicle controller; a rotary motor, electrically connected to the rotary motor controller; a rotary mechanism, mechanically connected to the rotary motor; an ISG motor controller, electrically connected to both the battery and the vehicle controller; an ISG motor, electrically connected to the ISG motor controller; an engine controller, electrically connected to the vehicle controller; an engine, electrically connected to the engine controller and mechanically connected to the ISG motor; and a hydraulic pump, mechanically connected to the ISG motor.

[0048] According to another aspect of this disclosure, a hybrid excavator is provided, comprising: a control system as described above.

[0049] According to another aspect of this disclosure, a computer-readable storage medium is provided that stores computer program instructions thereon, which, when executed by a processor, implement the control method as described above.

[0050] According to another aspect of this disclosure, a computer program product is provided, comprising a computer program or instructions that, when executed by a processor, implement the control method as described above.

[0051] In the above control method, the real-time power of the rotary motor, the maximum allowable charging power of the battery, and the maximum allowable discharging power of the battery are obtained. The maximum allowable effective discharge power of the battery is calculated based on the maximum allowable discharge power, and the maximum allowable effective charging power of the battery is calculated based on the maximum allowable charging power. When the real-time power of the rotary motor is greater than the maximum allowable effective discharge power of the battery and the maximum allowable effective discharge power of the battery is greater than 0, the integrated intelligent starter generator (ISG) is controlled to enter a power compensation mode, so that the ISG motor performs power generation to compensate for the power required by the rotary motor. When the real-time power of the rotary motor is less than the maximum allowable effective charging power of the battery and the maximum allowable effective charging power of the battery is less than 0, the ISG motor is controlled to enter a power consumption mode, so that the ISG motor performs drive operation to consume the excess power of the rotary motor. This reduces the risk of overcharging or over-discharging of the battery in the hybrid excavator.

[0052] Other features and advantages of this disclosure will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0053] The accompanying drawings, which form part of this specification, illustrate embodiments of this disclosure and, together with the specification, serve to explain the principles of this disclosure.

[0054] This disclosure will become clearer with reference to the accompanying drawings and the following detailed description, wherein:

[0055] Figure 1 This is a schematic block diagram illustrating the structure of a control system for a hybrid excavator according to some embodiments of the present disclosure;

[0056] Figure 2 This is a schematic diagram illustrating the control logic of a control system for a hybrid excavator according to some embodiments of the present disclosure;

[0057] Figure 3 This is a flowchart illustrating a control method for a hybrid excavator according to some embodiments of the present disclosure;

[0058] Figure 4 This is a flowchart illustrating a control method for a hybrid excavator according to other embodiments of the present disclosure;

[0059] Figure 5 This is a flowchart illustrating a control method for a hybrid excavator according to other embodiments of the present disclosure;

[0060] Figure 6 This is a schematic block diagram illustrating the structure of a vehicle controller according to some embodiments of the present disclosure;

[0061] Figure 7 This is a schematic block diagram illustrating the structure of a vehicle controller according to other embodiments of the present disclosure. Detailed Implementation

[0062] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present disclosure.

[0063] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0064] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0065] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0066] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0067] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0068] Figure 1 This is a schematic block diagram illustrating the structure of a control system for a hybrid excavator according to some embodiments of the present disclosure.

[0069] like Figure 1As shown, the control system includes: a Vehicle Control Unit (VCU) 110, a lever 120, a driving pedal 127, a gear shifter 125, a Battery Management System (BMS) 131, a battery 132, a Direct Current to Direct Current converter (DC / DC) 135, a rotary motor controller 141, a rotary motor 142, a rotary mechanism 143, an ISG motor controller 151, an ISG motor 152, an Engine Control Module (ECM) 161, an engine 162, and a hydraulic pump 165. For example, the lever 120 includes a left lever 121 and a right lever 122. The battery 132 is a power battery.

[0070] The control lever 120, travel pedal 127, and gear shifting device 125 are connected to the VCU 110. For example, the left control lever 121, right control lever 122, travel pedal 127, and gear shifting device 125 are respectively connected to the VCU 110 at low voltage for the operator to operate the excavator to perform corresponding walking, turning, or digging actions.

[0071] VCU 110 is used to execute the control method of the embodiments of this disclosure (described later). VCU 110 can be used to acquire information from various handle sensors (e.g., operation information of the lever, pedal information of the travel pedal, and gear position information of the gear shift device) and controller information (e.g., information from the rotary motor controller, information from the ISG motor controller, and information from the ECM, etc.) to control the output speed and torque of the rotary motor and ISG motor, thereby achieving power balance on the vehicle's high-voltage bus. VCU 110 is also used to output speed to the ECM so that the ECM can control the engine speed, etc.

[0072] BMS131 is connected to VCU 110 and battery 132 (e.g., low-voltage connection). BMS131 is used to control the power output of the battery and to feed back information such as battery bus voltage, maximum allowable discharge current, maximum allowable charging current, and battery SOC to VCU. Here, SOC refers to the remaining capacity of the battery.

[0073] Battery 132 is a vehicle energy storage device, connected to DC / DC 135, rotary motor controller 141, and ISG motor controller 151 (e.g., high-voltage connection). Battery 132 serves as a power battery to drive the rotary motor, ISG motor, and DC / DC, or to absorb the generated energy from the rotary motor and / or ISG motor.

[0074] ECM 161 is connected to VCU 110 and engine 162 respectively (e.g., low-voltage connection). ECM 161 is used to receive speed commands from VCU, control the engine to execute the corresponding speed, and feed back the engine's operating status to VCU.

[0075] Engine 162 is mechanically connected to the ISG motor. For example, engine 162 is coaxially connected to the ISG motor. Engine 162 can work together with ISG motor 152 to power hydraulic pump 165, or the engine can simultaneously drive the ISG motor to generate electricity and power the hydraulic pump.

[0076] The rotary motor controller 141 is connected to the VCU 110, the battery 132, and the rotary motor 142. For example, the rotary motor controller 141 is connected to the VCU 110 at low voltage, and to the battery 132 and the rotary motor 142 at high voltage. The rotary motor controller 141 is used to respond to the target torque sent by the VCU, convert the energy of the battery to drive the rotary motor (i.e., the rotary motor controller receives power from the battery to control the operation of the rotary motor), or recover the braking energy of the rotary motor into the battery, and monitor and feed back the status information of the rotary motor to the VCU.

[0077] The rotary motor 142 is mechanically connected to the rotary mechanism 143. The rotary motor 142 is used to convert electrical energy into mechanical energy to drive the rotary mechanism to accelerate, or to convert the mechanical energy of the rotary mechanism to decelerate into electrical energy and recover that electrical energy. For example, the rotary mechanism 143 includes a rotary reducer, a rotary gear ring, and a rotary platform, etc.

[0078] DC / DC 135 is connected to battery 132. DC / DC 135 is used to convert the high-voltage energy (i.e., high-voltage DC) of battery 132 into low-voltage energy (i.e., low-voltage DC) to provide energy for the operation of low-voltage components of the vehicle.

[0079] The ISG motor controller 151 is connected to the VCU 110, the battery 132, and the ISG motor 152. For example, the ISG motor controller 151 is connected to the VCU 110 at low voltage, and to the battery 132 and the ISG motor 152 at high voltage. The ISG motor controller 151 is used to respond to a target torque sent by the VCU by converting energy from the battery to drive the ISG motor (i.e., the ISG motor controller receives power from the battery to control the ISG motor), or to recover energy generated by the ISG motor back into the battery, and to monitor and feed back the ISG motor's status information to the VCU.

[0080] ISG motor 152 is coaxially connected to engine 162 and hydraulic pump 165. ISG motor 152 can be driven to assist the engine or generate electricity.

[0081] Hydraulic pump 165 provides power to the vehicle's hydraulic operating devices.

[0082] Figure 2 This is a schematic diagram illustrating the control logic of a control system for a hybrid excavator according to some embodiments of the present disclosure.

[0083] Regarding the control system of the aforementioned hybrid excavator equipped with an electric slewing mechanism, this disclosure provides a control method. This control method can be implemented in a VCU. For example, as... Figure 2 As shown, the control method may include at least one of driver intent analysis, engine control, rotary motor control, ISG motor control, and hydraulic pump control.

[0084] In driver intent analysis, by analyzing the gear position, the opening of the left and right levers, and the drive pedal, the target speeds required by the hydraulic pump and the rotary motor can be determined. Here, the larger the opening value, the larger the target speed value.

[0085] Engine control, rotary motor control, ISG motor control, and hydraulic pump control will be described in detail later.

[0086] Figure 3 This is a flowchart illustrating a control method for a hybrid excavator according to some embodiments of the present disclosure. The control method can be implemented in a VCU. The control method can implement ISG motor control. Figure 3 As shown, the control method includes steps S302 to S308.

[0087] In step S302, the real-time power of the rotary motor, the maximum allowable charging power of the battery, and the maximum allowable discharging power of the battery are obtained.

[0088] For example, the real-time power P of the rotary motor S for

[0089] P S =U S *I S / 1000, (1)

[0090] Among them, U S I is the bus voltage of the rotary motor controller. S This refers to the bus current of the rotary motor controller. For example, U S and I S It can be obtained through the rotary motor controller or by data acquisition.

[0091] In formula (1) above, the voltage U S The unit is V (volt), and the current I is... S The unit is A (ampere), and the power is P.S The unit is kW (kilowatt).

[0092] P S A positive value indicates that the rotary motor is driven. S A negative value indicates that the rotary motor is decelerated by electric braking.

[0093] For example, the maximum charging power P allowed by the battery mChg for

[0094] P mChg =U B *I mChg / 1000, (2)

[0095] Among them, U B I is the bus voltage of the battery (power battery). mChg The maximum allowable charging current for the battery. For example, U B It can be obtained through measurement. For example, I mChg The parameters can be calculated by the BMS based on the cell parameters and sent to the VCU via the CAN (Controller Area Network) bus.

[0096] In formula (2) above, the voltage U B The unit is V (volt), and the current I is... mChg The unit is A (ampere), and the power is P. mChg The unit is kW (kilowatt).

[0097] For example, the maximum allowable discharge power P of the battery mDis for

[0098] P mDis =U B *I mDis / 1000, (3)

[0099] Among them, U B I is the bus voltage of the battery (power battery). mDis This is the maximum allowable discharge current of the battery. For example, I mDis The parameters can be calculated by the BMS based on the cell parameters and sent to the VCU via the CAN bus.

[0100] In formula (3) above, the voltage U B The unit is V (volt), and the current I is... mDis The unit is A (ampere), and the power is P. mDis The unit is kW (kilowatt).

[0101] Additionally, the battery discharge current can be set to a positive value, and the battery charging current to a negative value; therefore, PmDis For a positive value, P mChg It is a negative value.

[0102] In step S304, the maximum allowable effective discharge power of the battery is calculated based on the maximum allowable discharge power of the battery, and the maximum allowable effective charging power of the battery is calculated based on the maximum allowable charging power of the battery.

[0103] In some embodiments, the maximum allowable effective discharge power P′ of the battery mDis for

[0104] P′ mDis =P mDis -P dcdc -P res (4)

[0105] Among them, P mDis P is the maximum allowable discharge power of the battery. dcdc P is the rated power of the DC-DC converter (DC / DC) in a hybrid excavator. res Reserved power value for the battery. For example, P res Take 5% to 10% of the battery's rated power. Here, P dcdc and P res All of these are known quantities.

[0106] In other embodiments, P may be disregarded when calculating the maximum allowable effective discharge power of the battery. dcdc and P res That is, it allows the battery to achieve its maximum allowable effective discharge power P′. mDis =P mDis .

[0107] In some embodiments, the maximum effective charging power P′ allowed by the battery mChg for

[0108] P′ mChg =P mChg -P dcdc +P res (5)

[0109] Among them, P mChg P is the maximum allowable charging power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res Reserved power value for the battery. For example, P res Take 5% to 10% of the battery's rated power. Here, P dcdc and P res All of these are known quantities.

[0110] In other embodiments, P may be disregarded when calculating the maximum allowable effective charging power of the battery. dcdc and P res That is, it allows the battery to achieve its maximum allowable effective charging power P′. mChg =P mChg .

[0111] In step S306, when the real-time power of the rotary motor is greater than the maximum effective discharge power allowed by the battery and the maximum effective discharge power allowed by the battery is greater than 0, the ISG motor is controlled to enter the power compensation mode so that the ISG motor can perform power generation operation to compensate for the power required by the rotary motor.

[0112] For a rotary motor, driving is positive power, and braking is negative power. That is, if the real-time power of the rotary motor is greater than 0, it indicates that the rotary motor is driving; if the real-time power of the rotary motor is less than 0, it indicates that the rotary motor is braking.

[0113] Here, in P S >P′ mDis >0 (for example, when P) S >P mDis -P dcdc -P res If the power of the rotary motor is greater than 0, it is determined that the acceleration drive power of the rotary motor is over the limit (exceeding the limit). This indicates that the discharge power of the battery cannot meet the power requirements of the rotary motor. Therefore, the ISG motor is controlled to enter the power compensation mode, that is, the engine is controlled to drive the ISG motor to generate electricity, thereby compensating for the power required by the rotary motor.

[0114] For example, the VCU can send the corresponding control signals to the ISG motor controller to control the ISG motor to enter the power compensation mode.

[0115] In step S308, when the real-time power of the rotary motor is less than the maximum effective charging power allowed by the battery and the maximum effective charging power allowed by the battery is less than 0, the ISG motor is controlled to enter the power consumption mode so that the ISG motor performs driving operation to consume the excess power of the rotary motor.

[0116] Here, the rotary motor generates electricity during braking; part of this electricity charges the battery, while the portion exceeding the battery's charging capacity is consumed by the ISG motor. In P S <P′ mChg <0 (e.g., P) S <P mChg -P dcdc +P resWhen the value is less than 0, it is determined that the rotary motor's deceleration electric braking power exceeds the limit (also known as the rotary motor's braking power generation power exceeds the limit). The ISG motor is then controlled to enter a power consumption mode, causing the ISG motor to perform drive operations to consume the excess power of the rotary motor. Here, the excess power is the portion of the rotary motor's braking power generation that exceeds the battery's allowable charging power.

[0117] For example, the VCU can send the corresponding control signals to the ISG motor controller to control the ISG motor to enter the power consumption mode.

[0118] Therefore, a control method for a hybrid excavator according to some embodiments of the present disclosure is provided. The control method includes: obtaining the real-time power of the slewing motor, the maximum allowable charging power of the battery, and the maximum allowable discharging power of the battery; calculating the maximum allowable effective discharge power of the battery based on the maximum allowable discharge power, and calculating the maximum allowable effective charging power of the battery based on the maximum allowable charging power; when the real-time power of the slewing motor is greater than the maximum allowable effective discharge power of the battery and the maximum allowable effective discharge power of the battery is greater than 0, controlling the integrated intelligent starter generator (ISG) motor to enter a power compensation mode, so that the ISG motor performs power generation operation to compensate for the power required by the slewing motor; and when the real-time power of the slewing motor is less than the maximum allowable effective charging power of the battery and the maximum allowable effective charging power of the battery is less than 0, controlling the ISG motor to enter a power consumption mode, so that the ISG motor performs drive operation to consume the excess power of the slewing motor. This reduces the risk of overcharging or over-discharging of the battery in the hybrid excavator.

[0119] In some embodiments, the control method further includes: when the real-time power of the rotary motor is less than or equal to the maximum allowable effective discharge power of the battery and the real-time power of the rotary motor is greater than 0 (i.e., 0... <P S ≤P′ mDis Alternatively, the real-time power of the rotary motor is greater than or equal to the maximum effective charging power allowed by the battery and the real-time power of the rotary motor is less than 0 (i.e., P′). mChg ≤P S When the SOC is less than 0, determine if the battery's SOC is below the SOC threshold. If the battery's SOC is less than the SOC threshold, control the ISG motor to enter forced generation mode so that the ISG motor can generate electricity to replenish the battery's charge. If the battery's SOC is greater than or equal to the SOC threshold, control the operation of the ISG motor according to the real-time power of the hydraulic pump. This control process belongs to ISG motor control.

[0120] Here, at 0 <P S ≤P′ mDis Or P′ mChg ≤PS If the SOC of the battery is less than 0, then the SOC threshold is less than 0. min Then the VCU can send the corresponding control signaling to the ISG motor controller to control the ISG motor to enter the forced generation mode if the battery's SOC is greater than or equal to the SOC threshold. min The VCU can then send corresponding control signals to the ISG motor controller to control the operation of the ISG motor based on the real-time power of the hydraulic pump. The SOC threshold can be set according to actual needs. For example, the SOC threshold... min The minimum threshold for setting the battery's SOC.

[0121] In the above embodiments, if the battery's SOC is less than the SOC threshold, it indicates that the battery's current charge is too low. Therefore, the ISG motor is controlled to enter forced generation mode to supplement the battery's charge. Conversely, if the battery's SOC is greater than or equal to the SOC threshold, it indicates that the battery's charge meets the requirements, and the operation of the ISG motor can be controlled based on the real-time power of the hydraulic pump. In this way, the ISG motor and the engine form a parallel hybrid power system to maintain the battery's SOC balance.

[0122] In some embodiments, controlling the operation of the ISG motor based on the real-time power of the hydraulic pump includes: when the real-time power of the hydraulic pump is greater than the engine's optimal power limit, controlling the ISG motor to enter a drive assist mode so that the ISG motor assists the operation of the hydraulic pump; when the real-time power of the hydraulic pump is less than or equal to the engine's optimal power limit, controlling the ISG motor to enter a zero-power follow mode so that the ISG motor follows the engine with zero power. This control process belongs to ISG motor control. Here, the engine's optimal power limit is a known quantity.

[0123] In drive-assist mode, the ISG motor outputs positive torque and works in conjunction with the engine to drive the load, effectively assisting the engine. In zero-power follow mode, the ISG motor outputs zero torque and neither drives nor generates electricity.

[0124] For example, if the real-time power of the hydraulic pump is greater than the engine's optimal power limit P opt Then the VCU can send the corresponding control signal to the ISG motor controller to control the ISG motor to enter the drive assist mode; if the real-time power of the hydraulic pump is less than or equal to the engine's optimal power limit value P opt Then the VCU can send the corresponding control signaling to the ISG motor controller to control the ISG motor to enter the zero power follow mode.

[0125] In the above embodiments, when the power demand is too high, the ISG motor can be driven to assist, thereby maintaining the engine within the optimal power range. When the power demand is not too high, the ISG motor can follow the engine in a zero-power manner.

[0126] In some embodiments, the control method further includes: calculating the target power of the ISG motor according to the different modes in which the ISG motor is located; and calculating the initial target torque of the ISG motor according to the target power of the ISG motor.

[0127] For example, the VCU can output the initial target torque of the ISG motor to the ISG motor controller to control the ISG motor to operate in the corresponding mode.

[0128] For example, the target power of the ISG motor is calculated based on the different modes it operates in, including: the target power P of the ISG motor when it is in power compensation mode. T-ISG for

[0129] P T-ISG =P S -(P mDis -P dcdc -P res (6)

[0130] Among them, P S P represents the real-time power of the rotary motor. mDis P is the maximum allowable discharge power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res Reserved power value for the battery.

[0131] In this way, the target power of the ISG motor in power compensation mode can be calculated, which facilitates the subsequent calculation of the initial target torque of the ISG motor in power compensation mode.

[0132] For example, the target power of the ISG motor can be calculated based on its different operating modes, including: the target power P of the ISG motor when it is in power consumption mode. T-ISG for

[0133] P T-ISG =P S -(P mChg -P dcdc +P res (7)

[0134] Among them, P S P represents the real-time power of the rotary motor. mChg P is the maximum allowable charging power of the battery. dcdcP represents the rated power of the DC-DC converter in a hybrid excavator. res Reserved power value for the battery.

[0135] In this way, the target power of the ISG motor in power consumption mode can be calculated, which facilitates the subsequent calculation of the initial target torque of the ISG motor in power consumption mode.

[0136] For example, the target power of the ISG motor can be calculated based on its different operating modes, including: the target power P of the ISG motor when it is in forced generation mode. T-ISG for

[0137] P T-ISG =P Chg (8)

[0138] Among them, P Chg This is a preset constant value. P Chg This refers to the preset power output value of the ISG motor in the program. For example, P Chg It can be equal to the rated power value of the ISG motor.

[0139] In this way, the target power of the ISG motor in forced generation mode can be calculated, which facilitates the subsequent calculation of the initial target torque of the ISG motor in forced generation mode.

[0140] For example, the target power of the ISG motor can be calculated based on its different operating modes, including: the target power P of the ISG motor when it is in drive assist mode. T-ISG for

[0141] P T-ISG =P P -P opt (9)

[0142] Among them, P P P is the real-time power of the hydraulic pump. opt This represents the engine's optimal power limit.

[0143] In this way, the target power of the ISG motor in drive assist mode can be calculated, which facilitates the subsequent calculation of the initial target torque of the ISG motor in drive assist mode.

[0144] For example, the target power of the ISG motor can be calculated based on its different modes, including: the target power P of the ISG motor when it is in zero-power follower mode. T-ISG It is 0. That is, P T-ISG =0.

[0145] In this way, the target power of the ISG motor in zero-power follow mode can be obtained, which facilitates the subsequent calculation of the initial target torque of the ISG motor in zero-power follow mode.

[0146] For example, the initial target torque T of the ISG motor T-ISG for

[0147] T T-ISG =P T-ISG *9550 / n ISG (10)

[0148] Among them, P T-ISG n is the target power of the ISG motor. ISG This refers to the real-time speed of the ISG motor. For example, the real-time speed of the ISG motor can be acquired by the ISG motor controller and the speed value can be sent to the VCU.

[0149] In the above formula (10), the target power P T-ISG The unit is kilowatt (kW), and the real-time rotational speed n ISG The unit is revolutions per minute (r / min), and the initial target torque T T-ISG The unit is Newton-meter (Nm).

[0150] In some embodiments, the control method further includes: when the ISG motor is in power compensation mode, power consumption mode, forced generation mode, or drive assist mode, correcting the initial target torque of the ISG motor using a fuzzy control algorithm to obtain a corrected target torque for the ISG motor; and controlling the operation of the ISG motor according to the corrected target torque. For example, after correcting the initial target torque, the VCU outputs the corrected target torque to the ISG motor controller to control the operation of the ISG motor according to the corrected target torque.

[0151] Here, in order to prevent engine speed fluctuations caused by the ISG motor's intervention, a fuzzy control algorithm is used to correct the torque of the ISG motor, which can stabilize the engine speed in real time.

[0152] In some embodiments, the initial target torque of the ISG motor is corrected using a fuzzy control algorithm, including: obtaining a target torque correction amount for the ISG motor based on the engine's target speed and speed error using the fuzzy control algorithm; and obtaining the corrected target torque T of the ISG motor based on the target torque correction amount. ISG ,

[0153] T ISG =min(T) T-ISG +ΔT,T ISG-max (11)

[0154] Among them, T T-ISG Let T be the initial target torque of the ISG motor, and ΔT be the target torque correction amount of the ISG motor. ISG-max This represents the maximum allowable torque of the ISG motor at the current speed.

[0155] In the above formula (11), min(T) T-ISG +ΔT,T ISG-max ) indicates taking T T-ISG +ΔT and T ISG-max The smaller value in the range. This prevents the corrected target torque from exceeding the maximum allowable torque of the ISG motor at the current speed, thus improving the safety of ISG motor operation.

[0156] For example, when the ISG motor is in any mode other than zero-power follow mode, because the ISG motor and engine are coaxially connected, the ISG motor's operation can cause engine speed fluctuations. Therefore, it is necessary to correct the ISG target torque to stabilize the engine speed. The target torque correction amount ΔT can be calculated using a fuzzy control algorithm. The engine's target speed and speed error are taken as the inputs to the fuzzy control, and the ISG motor's target torque correction amount ΔT is taken as the output. The membership functions for each variable are trigonometric functions. The designed fuzzy control algorithm is shown below:

[0157] Table 1 Classification of Engine Target Speed ​​Domain

[0158] Engine target speed domain Corresponding speed value low speed 1000rpm During rotational speed 1500rpm High speed 2000rpm

[0159] Here, rpm (revolutions per minute) means revolutions per minute.

[0160] For example, by setting corresponding speed thresholds, the target speed domain is determined by comparing the speed with the speed threshold. For instance, if the speed is less than the first speed threshold, the speed is in the low speed domain; if the first speed threshold is less than or equal to the second speed threshold, the speed is in the middle speed domain; and if the speed is greater than the second speed threshold, the speed is in the high speed domain. After determining the target speed domain, all speeds within a certain target speed domain are set to their corresponding speed values ​​(as shown in Table 1) to facilitate subsequent fuzzy control.

[0161] Table 2 Classification of Engine Speed ​​Error Universe

[0162] Engine speed error domain Corresponding error value The negative error is relatively large. -150rpm Zero error 0rpm The positive error is relatively large. 150rpm

[0163] Here, the speed error can be the allowable speed deviation during normal excavator operation. Similar to the method for determining the speed domain, a corresponding speed error threshold can be set. The speed error domain in which the speed error falls is determined by comparing the speed error with the speed error threshold. For example, if the speed error < the first speed error threshold (where the first speed error threshold is negative), then the speed error falls within the negative error domain; if the first speed error threshold ≤ the speed error ≤ the second speed error threshold (where the second speed error threshold is positive), then the speed error falls within the zero error domain; if the speed error > the second speed error threshold, then the speed error falls within the positive error domain. After determining the speed error domain in which the speed error falls, all speed errors within a certain speed error domain are set to their corresponding error values ​​(as shown in Table 2) to facilitate subsequent fuzzy control.

[0164] Table 3 Classification of ISG Torque Correction Domain

[0165] ISG Torque Correction Domain Corresponding correction amount Reduced significantly -100Nm Reduce moderate -50Nm Reduce smaller -25Nm Zero change 0Nm Increase smaller 25Nm Enlarged to a moderate size 50Nm Increase significantly 100Nm

[0166] The designed fuzzy control rules are shown in the table below:

[0167] Table 4 Fuzzy Rules

[0168] low speed During rotational speed High speed The negative error is relatively large. Increase smaller Enlarged to a moderate size Increase significantly Zero error Zero change Zero change Zero change The positive error is relatively large. Reduce appropriate Reduce moderate Reduced significantly

[0169] After calculating the target torque correction amount ΔT of the ISG motor using the fuzzy control algorithm, the target torque value T is sent to the ISG motor controller. ISG =min(T) T-ISG +ΔT,T ISG-max This avoids, as much as possible, the target torque exceeding the maximum torque that the motor itself can produce.

[0170] In some embodiments, the control method further includes: when the ISG motor is not in power consumption mode, controlling the hydraulic pump to maintain the current output pressure; when the ISG motor is in power consumption mode, determining whether the real-time power of the hydraulic pump is greater than the target power of the ISG motor; when the real-time power of the hydraulic pump is greater than or equal to the target power of the ISG motor, controlling the hydraulic pump to maintain the current output pressure; and when the real-time power of the hydraulic pump is less than the target power of the ISG motor, controlling the increase of the output pressure of the hydraulic pump. This achieves hydraulic pump control.

[0171] In the above embodiment, when the ISG motor is in power consumption mode, if the hydraulic pump output power is low, in order to avoid the ISG motor driving the engine to overspeed, the output pressure of the hydraulic pump is increased to maintain the power balance with the ISG motor drive.

[0172] For example, controlling the increase in hydraulic pump output pressure includes: calculating the pressure increment ΔP of the hydraulic pump output pressure.

[0173]

[0174] Among them, P T-ISG P is the target power of the ISG motor. P Let η be the real-time power of the hydraulic pump, Q be the flow rate of the hydraulic pump, and η be the efficiency of the hydraulic pump. The flow rate of the hydraulic pump can be obtained through measurement. The efficiency of the hydraulic pump can be determined through testing and can be a fixed value. For example, the efficiency of a hydraulic pump can range from 50% to 80%, depending on the components of the hydraulic pump itself.

[0175] For example, the real-time power P of a hydraulic pump P (For example, unit: kW)

[0176] P P =P*Q / (60η), (13)

[0177] Where P is the pressure of the hydraulic pump (e.g., the maximum working pressure of the hydraulic pump (unit: MPa (megapascals))), Q is the flow rate of the hydraulic pump (e.g., the output flow rate of the hydraulic pump (unit: L / min (liters per minute))), and η is the efficiency of the hydraulic pump. The pressure and flow rate of the hydraulic pump can be obtained by measurement. The efficiency of the hydraulic pump can be determined by testing.

[0178] In some embodiments, the control method further includes: determining a target speed of the hydraulic pump; calculating a corresponding throttle opening based on the target speed of the hydraulic pump; and controlling the engine operation based on the throttle opening. For example, the VCU can send the throttle opening to the ECU, which then controls the engine operation. This achieves engine control.

[0179] In this embodiment, since the engine, ISG motor, and hydraulic pump are coaxially connected and rotate at the same speed, the VCU calculates the corresponding throttle opening as Th = f(n p This opening value is responded to by the ECM and controlled by the engine. Here, f is the throttle opening MAP corresponding to the engine speed.

[0180] In some embodiments, the control method further includes: determining a target speed of the rotary motor; calculating a target torque of the rotary motor based on the target speed of the rotary motor and the actual speed of the rotary motor collected in real time; and controlling the operation of the rotary motor based on the target torque of the rotary motor. This achieves rotary motor control.

[0181] For example, the target torque T of the rotary motor s for

[0182] T s =min(T)i ,T s-max (14)

[0183] in,

[0184] Where e(t) is the target speed n of the rotary motor. s The actual rotational speed n of the rotary motor collected in real time s-act The real-time difference between them (i.e., e(t) = n) s -n s-act ), K p K is the proportionality coefficient. i K is the integral coefficient. d T is the differential coefficient. s-max This represents the maximum permissible real-time torque of the rotary motor. Here, the coefficient K... p K i and K d The value of can be obtained from experiments. Here, the target torque of the rotary motor is obtained through closed-loop calculation using PID control.

[0185] In formula (14) above, min(T) i ,T s-max ) indicates taking T i and T s-max The smaller value of the value can prevent the target torque of the rotary motor from exceeding the real-time maximum allowable torque of the rotary motor, thereby improving the safety of the rotary motor operation.

[0186] Figure 4 This is a flowchart illustrating a control method for a hybrid excavator according to some other embodiments of the present disclosure. This control method can be implemented in a VCU. Figure 4 As shown, the control method includes steps S402 to S424.

[0187] In step S402, real-time power is calculated. For example, the calculated real-time power includes: the real-time power of the rotary motor, the maximum allowable discharge power of the battery, the maximum allowable charging power of the battery, and the real-time power of the hydraulic pump.

[0188] In step S404, it is determined whether the slewing power (i.e., the real-time power of the slewing motor) exceeds the limit. If so, the process proceeds to step S406; otherwise, the process proceeds to step S412.

[0189] For example, the slewing power is considered to be out of limit if one of the following conditions is met:

[0190] 1. P S >P mDis -P dcdc -P res >0, acceleration drive power exceeds limit.

[0191] 2. P S <P mChg -P dcdc +P res <0, deceleration electric braking power exceeds limit;

[0192] Otherwise, the rotational power is considered to be within the limit.

[0193] In step S406, it is determined whether the power of the rotary motor is greater than 0. If it is (i.e., the power of the rotary motor is greater than 0), the process proceeds to step S408; otherwise (considering that the rotary power is not 0 during rotary operation, the power of the rotary motor is less than 0 at this time), the process proceeds to step S410.

[0194] In step S408, the ISG motor enters the power compensation mode and generates power to compensate for the power loss.

[0195] In step S410, the ISG motor enters the power consumption mode, and the ISG motor drives the motor to consume excess power.

[0196] In step S412, it is determined whether the battery's SOC is less than the SOC threshold. If so, the process proceeds to step S414; otherwise, the process proceeds to step S416.

[0197] In step S414, the ISG motor is forced to generate electricity. At this time, the battery charge is low. In order to maintain the battery's SOC balance, the ISG enters the forced power generation mode, and the ISG generates electricity to replenish the battery.

[0198] In step S416, it is determined whether the power of the hydraulic pump is greater than the upper limit of the engine's optimal power. If so, the process proceeds to step S418; otherwise, the process proceeds to step S420.

[0199] In step S418, the ISG motor enters the drive assist mode.

[0200] In step S420, the ISG motor enters zero-power follow mode.

[0201] In step S422, the initial target torque of the ISG motor is calculated.

[0202] In step S424, the target torque of the ISG motor is corrected.

[0203] Thus, a control method for a hybrid excavator according to other embodiments of this disclosure is provided. This control method can reduce the problem of insufficient acceleration or braking in hybrid excavators equipped with an electric slewing mechanism when the slewing power demand exceeds the battery's allowable power. By using the ISG motor as an auxiliary power source, when the slewing motor power exceeds its limit, the ISG provides additional power compensation or consumption, which can reduce the risk of battery overcharging or over-discharging. Especially when the battery is at low SOC or at low temperatures, the battery power is limited, and the ISG motor as an auxiliary power source can meet the peak power demand of the slewing motor during acceleration and deceleration, without the need for additional braking resistors to consume braking power. Furthermore, to prevent engine speed fluctuations caused by the ISG motor's intervention, the torque of the ISG motor is corrected using a fuzzy control algorithm, which can stabilize the engine speed in real time.

[0204] Figure 5 This is a flowchart illustrating a control method for a hybrid excavator according to some other embodiments of the present disclosure. This control method can be implemented in a VCU. Figure 5 As shown, the control method includes steps S502 to S508.

[0205] In step S502, it is determined whether the ISG motor is in power consumption mode. If so, the process proceeds to step S504; otherwise, the process proceeds to step S506.

[0206] In step S504, it is determined whether the power of the hydraulic pump is greater than the power consumed by the ISG. If so, the process proceeds to step S506; otherwise, the process proceeds to step S508.

[0207] In step S506, maintain the current pressure.

[0208] In step S508, the pressure increment is calculated to increase the output pressure.

[0209] Thus, a control method for a hybrid excavator according to some other embodiments of the present disclosure is provided. This control method is for hydraulic pump control. In this method, when the ISG motor is not in power consumption mode, the hydraulic pump maintains its current output pressure. When the ISG motor is in power consumption mode, it is necessary to determine the power P of the hydraulic pump. P Is it greater than the target power P of the ISG? T-ISGIf so, it means that the load power at the hydraulic end can consume the drive power of the ISG motor, and the hydraulic pump continues to maintain the current output pressure; otherwise, since the ISG motor and engine are coaxially connected, the ISG drive power will completely drive the engine to overspeed (this is because the hydraulic pump represents the current load, and the engine and ISG motor drive torque together drive the load. If the current load is relatively small, it will cause excessive power output from the engine and ISG motor, leading to engine overspeed). To avoid this phenomenon as much as possible, the output pressure of the hydraulic pump can be increased to maintain power balance with the ISG. For example, as mentioned above, the pressure increment is...

[0210] For hybrid excavators equipped with an electric slewing mechanism and an ISG motor, since the power battery, slewing motor, and ISG motor are all high-voltage power components, and both the slewing motor and ISG motor have two operating modes—power generation and drive—the power on the vehicle's high-voltage bus is limited. Especially during the start-up and stop of the slewing system, the slewing motor needs a large peak drive and power generation capacity to meet the acceleration requirements for starting and braking. When the battery's SOC is low or the ambient temperature is low, the maximum allowable charge and discharge power of the battery will be significantly affected. To avoid overcharging or over-discharging of the power battery, the power output of the ISG motor, slewing motor, and power battery must be rationally allocated. Furthermore, it is necessary to address the engine speed fluctuations caused by the ISG motor during operation.

[0211] Therefore, embodiments of this disclosure provide a hybrid excavator control system and method with an electric slewing mechanism as described above. When the slewing power demand exceeds the charging and discharging power of the power battery, the ISG motor is controlled to supplement or consume power; otherwise, the ISG motor is used to maintain battery SOC balance and assist the engine. A fuzzy control algorithm is used to correct the ISG motor torque in real time, stabilizing the engine speed. Through this method, the ISG motor can serve as an auxiliary energy source for the slewing motor, absorbing or releasing power, reducing the risk of battery overcharging or over-discharging, maintaining battery SOC balance, and also reducing battery power consumption, increasing overall machine drive power, and stabilizing engine speed.

[0212] To address the aforementioned technical problems, embodiments of this disclosure provide the control method described above, which can achieve the following effects:

[0213] (1) In the method of this embodiment, the ISG motor is used as an auxiliary power source. When the power of the rotary motor exceeds the limit, the ISG performs additional power compensation or consumption, which can avoid the battery from overcharging or over-discharging. Especially when the battery is at low SOC or low temperature, the battery power is limited. The ISG motor as an auxiliary power source can meet the peak power requirements of the rotary motor during acceleration and deceleration, and there is no need to set up an additional braking resistor to consume braking power.

[0214] (2) The ISG motor and the engine form a parallel hybrid power system to maintain the battery SOC balance, and can drive the assist when the power demand is too high, so as to keep the engine in the optimal power range.

[0215] (3) In order to prevent engine speed fluctuations caused by the ISG motor’s intervention, the torque of the ISG motor is corrected by a fuzzy control algorithm, which can stabilize the engine speed in real time.

[0216] (4) When the ISG motor consumes power, and the hydraulic pump output power is low, in order to avoid the engine being driven by the ISG to overspeed, the output pressure of the hydraulic pump is increased to maintain the balance with the ISG drive power.

[0217] In the preceding description, engine speed can be controlled by throttle opening; alternatively, other control methods can also be used. In this disclosure, increasing the output power of the hydraulic pump can be achieved by increasing the output pressure, or by increasing the output flow rate.

[0218] Figure 6 This is a schematic block diagram illustrating the structure of a vehicle controller according to some embodiments of the present disclosure. The vehicle controller includes a memory 610 and a processor 620. Wherein:

[0219] The memory 610 can be a disk, flash memory, or any other non-volatile storage medium. The memory is used for storing... Figures 3 to 5 At least one of the instructions in the corresponding embodiment.

[0220] Processor 620 is coupled to memory 610 and can be implemented as one or more integrated circuits, such as a microprocessor or microcontroller. Processor 620 executes instructions stored in memory, which can reduce the risk of overcharging or over-discharging the battery power of the hybrid excavator.

[0221] In one embodiment, it can also be as follows: Figure 7As shown, the vehicle controller 700 includes a memory 710 and a processor 720. The processor 720 is coupled to the memory 710 via a BUS bus 730. The vehicle controller 700 can also be connected to an external storage device 750 via a storage interface 740 to access external data, and can also be connected to a network or another computer system (not shown) via a network interface 760, which will not be described in detail here.

[0222] In this embodiment, by storing data instructions in a memory and then processing the instructions by a processor, the risk of overcharging or over-discharging the battery power of the hybrid excavator can be reduced.

[0223] In some embodiments of this disclosure, a control system for a hybrid excavator is also provided. This control system includes a vehicle controller as described above, for example, such as... Figure 6 or Figure 7 The vehicle controller shown.

[0224] In some embodiments, such as Figure 1 As shown, the control system may further include: a control lever, a driving pedal, and a gear shifting device, all electrically connected to the vehicle controller; a battery management system, electrically connected to the vehicle controller; a battery (power battery), electrically connected to the battery management system; a DC-DC converter, electrically connected to the battery; a rotary motor controller, electrically connected to both the battery and the vehicle controller; a rotary motor, electrically connected to the rotary motor controller; a rotary mechanism, mechanically connected to the rotary motor; an ISG motor controller, electrically connected to both the battery and the vehicle controller; an ISG motor, electrically connected to the ISG motor controller; an engine controller, electrically connected to the vehicle controller; an engine, electrically connected to the engine controller and mechanically connected to the ISG motor; and a hydraulic pump, mechanically connected to the ISG motor.

[0225] In some embodiments of this disclosure, a hybrid excavator is also provided. The hybrid excavator includes a control system as described above, for example, such as... Figure 1 The control system shown.

[0226] In some embodiments of this disclosure, a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) is also provided, having stored thereon computer program instructions that are implemented when executed by a processor. Figures 3 to 5The disclosure includes at least one step of the method in a corresponding embodiment. Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, apparatus, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0227] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. 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, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0228] 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.

[0229] 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.

[0230] In some embodiments of this disclosure, a computer program product is also provided, which includes a computer program or instructions that, when executed by a processor, implement the control method as described above.

[0231] This concludes the detailed description of the present disclosure. To avoid obscuring the concept of the disclosure, some details known in the art have not been described. Those skilled in the art will fully understand how to implement the technical solutions disclosed herein based on the above description.

[0232] While specific embodiments of this disclosure have been described in detail by way of example, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. A control method for a hybrid excavator, comprising: Obtain the real-time power of the rotary motor, the maximum allowable charging power of the battery, and the maximum allowable discharging power of the battery; The maximum allowable effective discharge power of the battery is calculated based on the maximum allowable discharge power of the battery, and the maximum allowable effective charging power of the battery is calculated based on the maximum allowable charging power of the battery. When the real-time power of the rotary motor is greater than the maximum effective discharge power allowed by the battery and the maximum effective discharge power allowed by the battery is greater than 0, the integrated intelligent start-drive generator (ISG) motor is controlled to enter the power compensation mode so that the ISG motor can perform power generation operation to compensate for the power required by the rotary motor. When the real-time power of the rotary motor is less than the maximum effective charging power allowed by the battery and the maximum effective charging power allowed by the battery is less than 0, the ISG motor is controlled to enter the power consumption mode so that the ISG motor performs driving operation to consume the excess power of the rotary motor. If the real-time power of the rotary motor is less than or equal to the maximum allowable effective discharge power of the battery and the real-time power of the rotary motor is greater than 0, or if the real-time power of the rotary motor is greater than or equal to the maximum allowable effective charging power of the battery and the real-time power of the rotary motor is less than 0, determine whether the state of charge (SOC) of the battery is less than the SOC threshold. When the SOC of the battery is less than the SOC threshold, the ISG motor is controlled to enter the forced power generation mode so that the ISG motor can generate electricity to replenish the battery's power. and When the SOC of the battery is greater than or equal to the SOC threshold, the operation of the ISG motor is controlled according to the real-time power of the hydraulic pump. The operation of the ISG motor is controlled based on the real-time power of the hydraulic pump, including: When the real-time power of the hydraulic pump exceeds the engine's optimal power limit, the ISG motor is controlled to enter drive assist mode, so that the ISG motor assists the operation of the hydraulic pump; and When the real-time power of the hydraulic pump is less than or equal to the optimal power limit of the engine, the ISG motor is controlled to enter the zero-power follow mode so that the ISG motor follows the engine in a zero-power manner.

2. The control method according to claim 1, wherein, The maximum allowable effective discharge power P′ of the battery mDis for P′ mDis =P mDis -P dcdc -P res , Among them, P mDis P is the maximum allowable discharge power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

3. The control method according to claim 1, wherein, The maximum allowable effective charging power P′ of the battery mChg for P′ mChg =P mChg -P dcdc +P res , Among them, P mChg P is the maximum allowable charging power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

4. The control method according to claim 1 further includes: Calculate the target power of the ISG motor based on the different modes in which the ISG motor is in; and The initial target torque of the ISG motor is calculated based on the target power of the ISG motor.

5. The control method according to claim 4, wherein, Calculate the target power of the ISG motor based on the different modes it is in, including: When the ISG motor is in the power compensation mode, the target power P of the ISG motor is... T-ISG for P T-ISG =P S -(P mDis -P dcdc -P res ), Among them, P S P represents the real-time power of the rotary motor. mDis P is the maximum allowable discharge power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

6. The control method according to claim 4, wherein, Calculate the target power of the ISG motor based on the different modes it is in, including: When the ISG motor is in the power consumption mode, the target power P of the ISG motor is... T-ISG for P T-ISG =P S -(P mChg -P dcdc +P res ), Among them, P S P represents the real-time power of the rotary motor. mChg P is the maximum allowable charging power of the battery. dcdc P represents the rated power of the DC-DC converter in a hybrid excavator. res The reserved power value for the battery.

7. The control method according to claim 4, wherein, Calculate the target power of the ISG motor based on the different modes it is in, including: When the ISG motor is in the forced power generation mode, the target power P of the ISG motor is... T-ISG for P T-ISG =P Chg , Among them, P Chg This is a preset constant value.

8. The control method according to claim 4, wherein, Calculate the target power of the ISG motor based on the different modes it is in, including: When the ISG motor is in the drive assist mode, the target power P of the ISG motor is... T-ISG for P T-ISG =P P -P opt , Among them, P P P is the real-time power of the hydraulic pump. opt This represents the optimal upper limit of the engine's power output.

9. The control method according to claim 4, wherein, Calculate the target power of the ISG motor based on the different modes it is in, including: When the ISG motor is in zero-power follower mode, the target power P of the ISG motor is... T-ISG It is 0.

10. The control method according to claim 4, wherein, The initial target torque T of the ISG motor T-ISG for T T-ISG =P T-ISG *9550 / n ISG , Among them, P T-ISG n is the target power of the ISG motor. ISG The real-time rotational speed of the ISG motor is given.

11. The control method according to claim 4, further comprising: When the ISG motor is in the power compensation mode, the power consumption mode, the forced generation mode, or the drive assist mode, the initial target torque of the ISG motor is corrected by a fuzzy control algorithm to obtain the corrected target torque of the ISG motor. and The operation of the ISG motor is controlled according to the corrected target torque of the ISG motor.

12. The control method according to claim 11, wherein, The initial target torque of the ISG motor is corrected using a fuzzy control algorithm, including: Using a fuzzy control algorithm, the target torque correction amount of the ISG motor is obtained based on the engine's target speed and speed error; and The corrected target torque T of the ISG motor is obtained based on the target torque correction amount of the ISG motor. ISG , T ISG =min(T T-ISG +ΔT,T ISG-max ), Among them, T T-ISG Let T be the initial target torque of the ISG motor, and ΔT be the target torque correction amount of the ISG motor. ISG-max This represents the maximum allowable torque of the ISG motor at the current speed.

13. The control method according to claim 1, further comprising: When the ISG motor is not in the power consumption mode, the hydraulic pump is controlled to maintain the current output pressure; When the ISG motor is in the power consumption mode, determine whether the real-time power of the hydraulic pump is greater than the target power of the ISG motor; When the real-time power of the hydraulic pump is greater than or equal to the target power of the ISG motor, the hydraulic pump is controlled to maintain the current output pressure. and If the real-time power of the hydraulic pump is less than the target power of the ISG motor, the output pressure of the hydraulic pump is controlled to increase.

14. The control method according to claim 13, wherein, Controlling the increase in the output pressure of the hydraulic pump includes: Calculate the pressure increment ΔP of the hydraulic pump's output pressure. Among them, P T-ISG P is the target power of the ISG motor. P Let η be the real-time power of the hydraulic pump, Q be the flow rate of the hydraulic pump, and η be the efficiency of the hydraulic pump.

15. The control method according to claim 1, further comprising: Determine the target speed of the hydraulic pump; Calculate the corresponding throttle opening based on the target speed of the hydraulic pump; and The engine operation is controlled according to the throttle opening.

16. The control method according to claim 1, further comprising: Determine the target speed of the rotary motor; The target torque of the rotary motor is calculated based on the target speed of the rotary motor and the actual speed of the rotary motor collected in real time. and The operation of the rotary motor is controlled according to the target torque of the rotary motor.

17. The control method according to claim 16, wherein, The target torque T of the rotary motor s for T s =min(T i ,T s-max ), in, Where e(t) is the target speed n of the rotary motor. s The actual rotational speed n of the rotary motor was collected in real time. s-act The real-time difference between them, K p K is the proportionality coefficient. i K is the integral coefficient. d T is the differential coefficient. s-max This is the maximum allowable real-time torque for the rotary motor.

18. A vehicle controller, comprising: Memory; as well as A processor coupled to the memory, the processor being configured to execute the control method as described in any one of claims 1 to 17 based on instructions stored in the memory.

19. A control system for a hybrid excavator, comprising: The vehicle controller as described in claim 18.

20. The control system according to claim 19, further comprising: The control lever, driving pedal, and gear shifting device are electrically connected to the vehicle controller, respectively. The battery management system is electrically connected to the vehicle controller; The battery is electrically connected to the battery management system; A DC-DC converter, electrically connected to the battery; The rotary motor controller is electrically connected to both the battery and the vehicle controller. A rotary motor, electrically connected to the rotary motor controller; The rotary mechanism is mechanically connected to the rotary motor; The ISG motor controller is electrically connected to both the battery and the vehicle controller. The ISG motor is electrically connected to the ISG motor controller. The engine controller is electrically connected to the vehicle controller. The engine is electrically connected to the engine controller and mechanically connected to the ISG motor; and A hydraulic pump is mechanically connected to the ISG motor.

21. A hybrid excavator, comprising: The control system as described in claim 19 or 20.

22. A computer-readable storage medium having stored thereon computer program instructions that, when executed by a processor, implement the control method as described in any one of claims 1 to 17.

23. A computer program product comprising a computer program or instructions that, when executed by a processor, implement the control method as described in any one of claims 1 to 17.

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