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

Abstract

The present disclosure provides a control method, a controller, a system, an excavator, a storage medium and a program product. The control method includes: obtaining the real-time power of the rotary motor, the maximum charging power allowed by the battery and the maximum discharging power allowed by the battery; calculating the maximum effective discharging power allowed by the battery according to the maximum discharging power allowed by the battery, and calculating the maximum effective charging power allowed by the battery according to the maximum charging power allowed by the battery; when the real-time power of the rotary motor is greater than the maximum effective discharging power allowed by the battery and the maximum effective discharging power allowed by the battery is greater than 0, controlling the ISG motor to enter a power compensation mode; and 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, controlling the ISG motor to enter a power consumption mode.

Description

Technical Field

[0001] The present disclosure relates to the field of new energy engineering machinery, and in particular to a control method, a controller, a system, an excavator, a storage medium and a program product. Background Art

[0002] Against the backdrop of energy conservation and emission reduction, the pace of green transformation in the construction machinery industry is gradually accelerating. Hybrid technology is being widely used in construction machinery products due to its advantages such as low cost, no endurance worries, energy conservation and emission reduction, and strong power. In a hybrid excavator with an electric slewing mechanism, the slewing motor drives the platform to rotate, decelerates through electric braking, and recovers braking energy. The ISG (Integrated Starter / Generator) motor can generate electricity to maintain the battery SOC (State of Charge) balance, or drive to assist the engine, so that the whole machine has higher energy utilization and power. Here, SOC is the remaining capacity of the battery.

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

[0004] A technical problem solved by the present disclosure is that in the related art, hybrid excavators are prone to battery overcharge or overdischarge.

[0005] According to one aspect of the present disclosure, a control method for a hybrid excavator is provided, including: obtaining the real-time power of a rotary motor, the maximum charging power allowed by a battery, and the maximum discharging power allowed by the battery; calculating the maximum effective discharge power allowed by the battery according to the maximum discharge power allowed by the battery, and calculating the maximum effective charging power allowed by the battery according to the maximum charging power allowed by 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, controlling the integrated intelligent starter drive generator ISG motor to enter a power compensation mode so that the ISG motor performs a power generation operation to compensate for the required power of the rotary motor; and 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, controlling the ISG motor to enter a power consumption mode so that the ISG motor performs a driving operation to consume excess power of the rotary motor.

[0006] In some embodiments, the maximum effective discharge power P' allowed by the battery mDis for

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

[0008] Among them, P mDis is the maximum discharge power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

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

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

[0011] Among them, P mChg is the maximum charging power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

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

[0013] In some embodiments, the operation of the ISG motor is controlled according to the real-time power of the hydraulic pump, including: when the real-time power of the hydraulic pump is greater than the optimal power upper limit of the engine, controlling the ISG motor to enter a driving 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 optimal power upper limit of the engine, controlling the ISG motor to enter a zero-power following mode so that the ISG motor follows the operation in a zero-power manner.

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

[0015] In some embodiments, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: 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 is the real-time power of the rotary motor, P mDis is the maximum discharge power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

[0018] In some embodiments, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: 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 is the real-time power of the rotary motor, P mChg is the maximum charging power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

[0021] In some embodiments, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the forced power 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 is a preset constant value.

[0024] In some embodiments, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the driving 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 is the real-time power of the hydraulic pump, P opt is the optimal power upper limit value of the engine.

[0027] In some embodiments, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the zero power following mode, the target power P of the ISG motor is calculated. T-ISG is 0.

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

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

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

[0031] In some embodiments, the control method also includes: when the ISG motor is in the power compensation mode, the power consumption mode, the forced power generation mode or the drive assist mode, correcting the initial target torque of the ISG motor by a fuzzy control algorithm to obtain a 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 by a fuzzy control algorithm, including: obtaining a target torque correction amount of the ISG motor based on a target speed and a speed error of the engine by a fuzzy control algorithm; obtaining a corrected target torque T of the ISG motor according to the target torque correction amount of the ISG motor ISG ,

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

[0034] Among them, T T-ISG is the initial target torque of the ISG motor, ΔT is the target torque correction of the ISG motor, T ISG-max is the maximum torque allowed by the ISG motor at the current speed.

[0035] In some embodiments, the control method also 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; when the real-time power of the hydraulic pump is less than the target power of the ISG motor, controlling to increase the output pressure of the hydraulic pump.

[0036] In some embodiments, controlling to increase the output pressure of the hydraulic pump comprises: calculating a pressure increment ΔP of the output pressure of the hydraulic pump,

[0037]

[0038] Among them, P T-ISG is the target power of the ISG motor, P P is the real-time power of the hydraulic pump, Q is the flow rate of the hydraulic pump, and η is 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 according to the target speed of the hydraulic pump; and controlling the operation of the engine according to the throttle opening.

[0040] In some embodiments, the control method also 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 an 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] Wherein, e(t) is the target speed n of the rotary motor. s The actual speed n of the rotary motor collected in real time s-act The real-time difference between p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, T s-max is the real-time maximum torque allowed by the rotary motor.

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

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

[0047] In some embodiments, the control system also includes: an operating lever, a travel pedal and a gear device, which are electrically connected to the vehicle controller respectively; a battery management system, which is electrically connected to the vehicle controller; a battery, which is electrically connected to the battery management system; a DC-DC converter, which is electrically connected to the battery; a rotary motor controller, which is electrically connected to the battery and the vehicle controller respectively; a rotary motor, which is electrically connected to the rotary motor controller; a rotary mechanism, which is mechanically connected to the rotary motor; an ISG motor controller, which is electrically connected to the battery and the vehicle controller respectively; an ISG motor, which is electrically connected to the ISG motor controller; an engine controller, which is electrically connected to the vehicle controller; an engine, which is electrically connected to the engine controller and mechanically connected to the ISG motor; and a hydraulic pump, which is mechanically connected to the ISG motor.

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

[0049] According to another aspect of the present disclosure, a computer-readable storage medium is provided, on which computer program instructions are stored. When the computer program instructions are executed by a processor, the control method as described above is implemented.

[0050] According to another aspect of the present disclosure, a computer program product is provided. The computer program product includes a computer program or instructions. When the computer program or instructions are executed by a processor, the control method as described above is implemented.

[0051] In the above control method, the real-time power of the rotary motor, the maximum charging power allowed by the battery, and the maximum discharging power allowed by the battery are obtained; the maximum effective discharge power allowed by the battery is calculated according to the maximum discharge power allowed by the battery, and the maximum effective charging power allowed by the battery is calculated according to the maximum charging power allowed by 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 starter drive generator ISG motor is controlled to enter the power compensation mode so that the ISG motor performs power generation operation to compensate for the required power of the rotary motor; and 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. In this way, the risk of overcharging or over-discharging of the battery power of the hybrid excavator can be reduced.

[0052] Other features and advantages of the present disclosure will become apparent from the following detailed description of exemplary embodiments of the present disclosure with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The accompanying drawings, which constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0054] The present disclosure may be more clearly understood from the following detailed description with reference to the accompanying drawings, in which:

[0055] Figure 1 is a block diagram schematically showing a control system for a hybrid excavator according to some embodiments of the present disclosure;

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

[0057] Figure 3 is a flow chart showing a control method for a hybrid excavator according to some embodiments of the present disclosure;

[0058] Figure 4 is a flow chart showing a control method for a hybrid excavator according to other embodiments of the present disclosure;

[0059] Figure 5 is a flow chart showing a control method for a hybrid excavator according to other embodiments of the present disclosure;

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

[0061] Figure 7 It is a block diagram schematically showing the structure of a vehicle controller according to other embodiments of the present disclosure. DETAILED DESCRIPTION

[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 the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present disclosure unless otherwise specifically stated.

[0063] At the same time, it should be understood that for the convenience of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship.

[0064] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the present disclosure, its application, or uses.

[0065] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, 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 limiting. Therefore, other examples of the exemplary embodiments may have different values.

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

[0068] Figure 1 is a block diagram schematically showing a 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, an operating lever 120, a travel pedal 127, a gear device 125, a BMS (Battery Management System) 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 controller (Engine Control Module, ECM) 161, an engine 162 and a hydraulic pump 165. For example, the operating lever 120 includes a left operating lever 121 and a right operating lever 122. The battery 132 is a power battery.

[0070] The operating lever 120, the travel pedal 127 and the shift device 125 are connected to the VCU 110. For example, the left operating lever 121, the right operating lever 122, the travel pedal 127 and the shift device 125 are respectively connected to the VCU 110 at a low voltage, so that the driver can operate the excavator to perform corresponding walking, rotating or digging actions.

[0071] VCU 110 is used to execute the control method of the embodiment of the present disclosure (described later). The VCU 110 can be used to obtain various handle sensors (for example, operation information of the operating lever, pedal information of the travel pedal, and gear information of the gear device) and controller information (for example, information sent from the rotary motor controller, information sent from the ISG motor controller, and information sent from the ECM, etc.), control the output speed and torque of the rotary motor and the ISG motor, and achieve power balance on the high-voltage bus of the whole vehicle. VCU 110 is also used to output the speed to the ECM so that the ECM controls the speed of the engine, etc.

[0072] The BMS 131 is connected to the VCU 110 and the battery 132 (e.g., low voltage connection). The BMS 131 is used to control the power output of the battery and to feed back the battery bus voltage, the maximum allowable discharge current, the maximum allowable charge current, and the SOC information of the battery to the VCU. Here, the SOC is the remaining capacity of the battery.

[0073] The battery 132 is a vehicle energy storage device, which is respectively connected (e.g., high voltage connection) to the DC / DC 135, the swing motor controller 141, and the ISG motor controller 151. The battery 132 is used as a power battery to drive the swing motor, the ISG motor, and the DC / DC, or absorb the power generation energy of the swing motor and / or the ISG motor.

[0074] The ECM 161 is connected to the VCU 110 and the engine 162 (eg, low voltage connection) respectively. The ECM 161 is used to receive the speed command from the VCU, control the engine to execute the corresponding speed, and feed back the running status of the engine to the VCU.

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

[0076] The rotary motor controller 141 is connected to the VCU 110, the battery 132 and the rotary motor 142, respectively. For example, the rotary motor controller 141 is connected to the VCU 110 at low voltage, and the rotary motor controller 141 is connected to the battery 132 and the rotary motor 142 at high voltage, respectively. 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 to work (that is, the rotary motor controller receives the power provided by the battery to control the operation of the rotary motor), or recover the braking energy of the rotary motor into the battery, monitor and feedback 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 mechanical energy of the rotary mechanism to decelerate into electrical energy and recover the electrical energy. For example, the rotary mechanism 143 includes a rotary reducer, a rotary gear ring, and a rotary platform.

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

[0079] The ISG motor controller 151 is respectively 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 the ISG motor controller 151 is respectively connected to the battery 132 and the ISG motor 152 at high voltage. The ISG motor controller 151 is used to respond to the target torque sent by the VCU, convert the energy of the battery to drive the ISG motor to work (that is, the ISG motor controller receives the power provided by the battery to control the operation of the ISG motor), or recover the energy generated by the ISG motor into the battery, monitor and feedback the status information of the ISG motor to the VCU.

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

[0081] The hydraulic pump 165 provides power for the hydraulic working device of the whole vehicle.

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

[0083] The present disclosure provides a control method for the control system of the hybrid excavator with an electric slewing mechanism. The control method can be implemented in the VCU. For example, Figure 2 As shown, the control method may include at least one of driver intention analysis, engine control, swing motor control, ISG motor control, and hydraulic pump control.

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

[0085] The engine control, the swing motor control, the ISG motor control and the hydraulic pump control will be described in detail later.

[0086] Figure 3 is a flow chart showing 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 realize 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 charging power allowed by the battery, and the maximum discharging power allowed by 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 is the bus voltage of the rotary motor controller, I S is 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 through acquisition.

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

[0092] P S When it is positive, it indicates rotary motor drive, P S A negative value indicates that the rotary motor is decelerating by electric braking.

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

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

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

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

[0097] For example, the maximum discharge power allowed by the battery is P mDis for

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

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

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

[0101] In addition, the battery discharge current can be set to a positive value and the battery charge current to a negative value. Therefore, PmDis is a positive value, P mChg Is a negative value.

[0102] In step S304, the maximum effective discharge power allowed by the battery is calculated according to the maximum discharge power allowed by the battery, and the maximum effective charging power allowed by the battery is calculated according to the maximum charging power allowed by the battery.

[0103] In some embodiments, the maximum effective discharge power P' allowed by the battery mDis for

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

[0105] Among them, P mDis is the maximum discharge power allowed by the battery, P dcdc is the rated power of the DC / DC converter in the hybrid excavator, P res The reserved power value of the battery. For example, P res Take 5% to 10% of the battery's rated power. Here, P dcdc and P res All are known quantities.

[0106] In other embodiments, P may not be considered when calculating the maximum effective discharge power allowed by the battery. dcdc and P res , that is, the maximum effective discharge power P' allowed by the battery 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 is the maximum charging power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res The reserved power value of the battery. For example, P res Take 5% to 10% of the battery's rated power. Here, P dcdc and P res All are known quantities.

[0110] In other embodiments, P may not be considered when calculating the maximum effective charging power allowed by the battery. dcdc and P res , that is, the maximum effective charging power P' allowed by the battery 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 performs power generation operation to compensate for the required power of 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 means that the rotary motor is driving; if the real-time power of the rotary motor is less than 0, it means 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 >0), it is determined that the acceleration drive power of the rotary motor is out of limit (outside the limit), indicating that the discharge power of the battery cannot meet the power requirement of the rotary motor at this time. 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 required power of the rotary motor.

[0114] For example, the VCU may send corresponding control signals to the ISG motor controller to control the ISG motor to enter a 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 excess power of the rotary motor.

[0116] Here, the slewing motor generates electricity when braking, part of which is charged to the battery, and the part exceeding the allowable charging power of the battery is driven and consumed by the ISG motor. S <P′ mChg <0 (e.g., P S <P mChg -P dcdc +P res<0), it is determined that the rotary motor deceleration electric braking power exceeds the limit (also known as the rotary motor braking power exceeds the limit), and the ISG motor is controlled to enter the power consumption mode, so that the ISG motor performs a driving operation to consume the excess power of the rotary motor. Here, the excess power is the part of the rotary motor braking power that exceeds the allowable charging power of the battery.

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

[0118] So far, 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 rotary motor, the maximum charging power allowed by the battery, and the maximum discharge power allowed by the battery; calculating the maximum effective discharge power allowed by the battery according to the maximum discharge power allowed by the battery, and calculating the maximum effective charging power allowed by the battery according to the maximum charging power allowed by 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, controlling the integrated intelligent starter drive generator ISG motor to enter the power compensation mode so that the ISG motor performs power generation operation to compensate for the required power of the rotary motor; and 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, controlling the ISG motor to enter the power consumption mode so that the ISG motor performs a driving operation to consume the excess power of the rotary motor. In this way, the risk of overcharging or over-discharging the battery power of the hybrid excavator can be reduced.

[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 effective discharge power allowed by the battery and the real-time power of the rotary motor is greater than 0 (ie, 0 <P S ≤P′ mDis ) or, 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 <0), determine whether the battery SOC is less than the SOC threshold; if the battery SOC is less than the SOC threshold, control the ISG motor to enter the forced power generation mode so that the ISG motor performs power generation to replenish the battery power; if the battery 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 <0, if the battery SOC is less than the SOC threshold SOC min , the VCU can send the corresponding control signal to the ISG motor controller to control the ISG motor to enter the forced power generation mode. If the battery SOC is greater than or equal to the SOC threshold SOC min , then the VCU can send the corresponding control signal to the ISG motor controller to control the operation of the ISG motor according to the real-time power of the hydraulic pump. The SOC threshold can be set according to actual needs. For example, the SOC threshold SOC min The minimum threshold of battery SOC is set.

[0121] In the above embodiment, if the battery SOC is less than the SOC threshold, it indicates that the current battery power is too low, so the ISG motor is controlled to enter the forced power generation mode to replenish the battery power; if the battery SOC is greater than or equal to the SOC threshold, it indicates that the battery power meets the power requirement, and the operation of the ISG motor can be controlled according to the real-time power of the hydraulic pump. In this way, the ISG motor and the engine form a parallel hybrid system to maintain the SOC balance of the battery.

[0122] In some embodiments, the operation of the ISG motor is controlled according to the real-time power of the hydraulic pump, including: when the real-time power of the hydraulic pump is greater than the optimal power upper limit of the engine, the ISG motor is controlled to enter the driving power 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 optimal power upper limit of the engine, the ISG motor is controlled to enter the zero power following mode so that the ISG motor follows the operation in a zero power manner. This control process belongs to the ISG motor control. Here, the optimal power upper limit of the engine is a known quantity.

[0123] In the driving assist mode, the ISG motor outputs a positive torque when driving, and outputs torque in conjunction with the engine to drive the load, which is equivalent to assisting the engine. In the zero power follow mode, the ISG motor currently outputs a torque of 0, and does not drive or generate electricity.

[0124] For example, if the real-time power of the hydraulic pump is greater than the optimal power upper limit value P of the engine opt , the VCU can send the corresponding control signal to the ISG motor controller to control the ISG motor to enter the driving assistance mode; if the real-time power of the hydraulic pump is less than or equal to the optimal power upper limit value P of the engine opt , the VCU can send the corresponding control signal to the ISG motor controller to control the ISG motor to enter the zero-power following mode.

[0125] In the above embodiment, when the required power is too large, the ISG motor can be driven to assist, thereby maintaining the engine within the optimal power. When the required power is not too large, the ISG motor can be driven to follow the operation in a zero-power mode.

[0126] In some embodiments, the control method further includes: calculating a target power of the ISG motor according to different modes of the ISG motor; and calculating an 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 a corresponding mode.

[0128] For example, according to the different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the power compensation mode, the target power P of the ISG motor is T-ISG for

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

[0130] Among them, P S is the real-time power of the rotary motor, P mDis is the maximum discharge power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res The reserved power value of the battery.

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

[0132] For another example, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the power consumption mode, the target power P of the ISG motor is T-ISG for

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

[0134] Among them, P S is the real-time power of the rotary motor, P mChg is the maximum charging power allowed by the battery, P dcdcis the rated power of the DC-DC converter in the hybrid excavator, P res The reserved power value of the battery.

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

[0136] For another example, according to different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the forced power generation mode, the target power P of the ISG motor is T-ISG for

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

[0138] Among them, P Chg is a preset constant value. Chg It is the power value of the ISG motor preset 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 when it is in the forced power generation mode can be calculated, which facilitates the subsequent calculation of the initial target torque of the ISG motor when it is in the forced power generation mode.

[0140] For another example, according to the different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the driving assist mode, the target power P of the ISG motor is T-ISG for

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

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

[0143] In this way, the target power of the ISG motor when it is in the driving assistance mode can be calculated, which facilitates the subsequent calculation of the initial target torque of the ISG motor when it is in the driving assistance mode.

[0144] For another example, according to the different modes of the ISG motor, the target power of the ISG motor is calculated, including: when the ISG motor is in the zero power following mode, the target power P of the ISG motor is T-ISG is 0. That is, P T-ISG =0.

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

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

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

[0148] Among them, P T-ISG is the target power of the ISG motor, n ISG is 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 is sent to the VCU.

[0149] In the above formula (10), the target power P T-ISG The unit is kilowatt (kW), the real-time speed n ISG The unit is revolutions per minute (r / min), 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 power generation mode or driving assist mode, the initial target torque of the ISG motor is corrected by a fuzzy control algorithm to obtain a 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. For example, after the VCU corrects the initial target torque, it 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 the engine speed fluctuation caused by the intervention of the ISG motor, the torque of the ISG motor is corrected through the fuzzy control algorithm, which can stabilize the engine speed in real time.

[0152] In some embodiments, the initial target torque of the ISG motor is corrected by a fuzzy control algorithm, including: obtaining a target torque correction amount of the ISG motor based on the target speed and speed error of the engine by the fuzzy control algorithm; and obtaining a corrected target torque T of the ISG motor according to the target torque correction amount of the ISG motor. ISG ,

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

[0154] Among them, T T-ISG is the initial target torque of the ISG motor, ΔT is the target torque correction of the ISG motor, T ISG-max It is the maximum torque allowed by the ISG motor at the current speed.

[0155] In the above formula (11), min(T T-ISG +ΔT,T ISG-max ) means taking T T-ISG +ΔT and T ISG-max This can prevent the corrected target torque from exceeding the maximum torque allowed by the ISG motor at the current speed, thereby improving the safety of the ISG motor operation.

[0156] For example, when the ISG motor is in a mode other than the zero power following mode, since the ISG motor and the engine are coaxially connected, the ISG motor will cause the engine speed to fluctuate when it intervenes in the work, so the ISG target torque needs to be corrected to stabilize the engine speed. The target torque correction ΔT can be calculated by the fuzzy control algorithm. The target speed of the engine and the speed error of the engine are taken as the input of the fuzzy control, the target torque correction ΔT of the ISG motor is taken as the output of the fuzzy control, and the membership function of each variable selects the trigonometric function. The designed fuzzy control algorithm is as follows:

[0157] Table 1 Classification of engine target speed domain

[0158] Engine target speed domain Corresponding speed value Low speed 1000rpm Speed 1500rpm High speed 2000rpm

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

[0160] For example, by setting the corresponding speed threshold, the target speed domain of the speed is determined by comparing the speed with the speed threshold. For example, if the speed < the first speed threshold, the speed is in the low speed domain; if the first speed threshold ≤ the speed ≤ the second speed threshold, the speed is in the medium speed domain; if the speed > the second speed threshold, the speed is in the high speed domain. After determining the target speed domain of the speed, all speeds in a certain target speed domain are set to the corresponding speed value (as shown in Table 1) to facilitate subsequent fuzzy control.

[0161] Table 2 Classification of engine speed error domain

[0162] Engine speed error domain Corresponding error value Large negative error -150rpm Zero Error 0rpm Large positive error 150rpm

[0163] Here, the speed error can be the speed deviation allowed in the normal operation of the excavator. Similar to the method for determining the speed domain, a corresponding speed error threshold can also be set, and the speed error domain in which the speed error is located can be 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 a negative value, the speed error is in a domain with a large negative error; if the first speed error threshold ≤ the speed error ≤ the second speed error threshold, where the second speed error threshold is a positive value, the speed error is in a domain with a zero error; if the speed error > the second speed error threshold, the speed error is in a domain with a large positive error. After determining the speed error domain in which the speed error is located, all speed errors in a certain speed error domain are set to the corresponding error value (as shown in Table 2) to facilitate subsequent fuzzy control.

[0164] Table 3 ISG torque correction domain classification

[0165] ISG torque correction domain Corresponding correction amount Reduce the larger -100Nm Reduce moderately -50Nm Smaller reduction -25Nm Zero Change 0Nm Small increase 25Nm Moderate increase 50Nm Larger increase 100Nm

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

[0167] Table 4 Fuzzy rules

[0168] Low speed Speed High speed Large negative error Small increase Moderate increase Larger increase Zero Error Zero Change Zero Change Zero Change Large positive error Reduce to a smaller size Reduce moderately Reduce the larger

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

[0170] 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, judging 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; when the real-time power of the hydraulic pump is less than the target power of the ISG motor, controlling to increase the output pressure of the hydraulic pump. This realizes the control of the hydraulic pump.

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

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

[0173]

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

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

[0176] P P =P*Q / (60η), (13)

[0177] Wherein, P is the pressure of the hydraulic pump (for example, the maximum working pressure of the hydraulic pump (unit: MPa (megapascals))), Q is the flow rate of the hydraulic pump (for example, the output flow rate of the hydraulic pump (unit: L / min (liter / 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 measured after testing.

[0178] In some embodiments, the control method further includes: determining a target speed of the hydraulic pump; calculating a corresponding throttle opening according to the target speed of the hydraulic pump; and controlling the operation of the engine according to the throttle opening. For example, the VCU can send the throttle opening to the ECU, and the operation of the engine is controlled by the ECU. This realizes engine control.

[0179] In this embodiment, since the engine, ISG motor and hydraulic pump are coaxially connected, the rotation speed is consistent. The VCU calculates the corresponding throttle opening as Th = f(n p ), the opening value is responded by the ECM and controls the engine to execute. Wherein, 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 according to the target speed of the rotary motor and an actual speed of the rotary motor acquired in real time; and controlling the operation of the rotary motor according to the target torque of the rotary motor. This realizes the control of the rotary motor.

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

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

[0183] in,

[0184] Where, e(t) is the target speed n of the rotary motor. s The actual speed n of the rotary motor collected in real time s-act The real-time difference between (ie, e(t) = n s -n s-act ), K p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, T s-max is the maximum torque allowed by the rotary motor. Here, the coefficient K p , K i and K d The value of can be measured according to the test. Here, the target torque of the rotary motor is calculated by the PID control closed loop.

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

[0186] Figure 4 FIG. 1 is a flow chart showing a control method for a hybrid excavator according to other embodiments of the present disclosure. The 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 discharge power allowed by the battery, the maximum charge power allowed by the battery, and the real-time power of the hydraulic pump.

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

[0189] For example, if one of the following conditions is met, the swing power is considered to be exceeded:

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

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

[0192] Otherwise, it is considered that the swing power does not exceed the limit.

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

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

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

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

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

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

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

[0200] In step S420, the ISG motor enters a zero power following 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] At this point, a control method for a hybrid excavator according to other embodiments of the present disclosure is provided. This control method can reduce the problem of insufficient acceleration or braking in a hybrid excavator equipped with an electric swing mechanism when the swing power demand exceeds the power allowed by the battery. By using the ISG motor as an auxiliary power source, when the swing motor power exceeds the limit, the ISG performs additional power compensation or consumption, which can reduce the risk of overcharging or over-discharging of the battery. 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 demand when the swing motor accelerates and decelerates, and there is no need to add additional braking resistors to consume braking power. In addition, in order to prevent the engine speed fluctuation caused by the intervention of the ISG motor, the torque of the ISG motor is corrected by a fuzzy control algorithm, so that the engine speed can be stabilized in real time.

[0204] Figure 5 FIG. 1 is a flow chart showing a control method for a hybrid excavator according to other embodiments of the present disclosure. The 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 the power consumption mode. If yes, the process proceeds to step S504; otherwise, the process proceeds to step S506.

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

[0207] In step S506, the current pressure is maintained.

[0208] In step S508, the pressure increment is calculated and the output pressure is increased.

[0209] So far, a control method for a hybrid excavator according to some other embodiments of the present disclosure is provided. The control method is used for hydraulic pump control. In the method, when the ISG motor is not in the power consumption mode, the hydraulic pump maintains the current output pressure. When the ISG motor is in the 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 ISG? T-ISGIf yes, it means that the load power of the hydraulic end can consume the driving power of the ISG motor, and the hydraulic pump continues to maintain the current output pressure; otherwise, since the ISG motor and the engine are coaxially connected, the ISG driving 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 jointly drive the load. If the current load is relatively small, the power output of the engine and ISG motor drive is too much, causing the engine to overspeed). In order to avoid this phenomenon as much as possible, the output pressure of the hydraulic pump can be increased to maintain the power balance with the ISG. For example, as mentioned above, the pressure increment is

[0210] For hybrid excavators with electric slewing mechanisms and ISG motors, since the power battery, slewing motor, and ISG motor are all high-voltage power components, the slewing motor and ISG motor have two working modes: power generation or driving. The power on the high-voltage bus of the vehicle is limited. Especially when the slewing system is started and stopped, the slewing motor needs to have a large peak drive and power generation power to meet the starting acceleration and braking acceleration requirements. When the battery SOC is low or the ambient temperature is low, the maximum charge and discharge power allowed by the battery will be greatly affected. In order to avoid overcharging or over-discharging of the power battery, the power output of the ISG motor, slewing motor, and power battery is reasonably allocated. In addition, it is necessary to solve the engine speed fluctuation caused by the ISG during operation.

[0211] Therefore, the embodiments of the present disclosure provide a control system and method for a hybrid excavator with an electric swing mechanism as described above. When the swing power demand exceeds the charging and discharging power of the power battery, the ISG motor is controlled to supplement power or consume power, otherwise the ISG motor is used to maintain the battery SOC balance and assist the engine. Through the fuzzy control algorithm, the ISG motor torque is corrected in real time to stabilize the engine speed. Through the above method, the ISG motor can be used as an auxiliary energy source for the swing motor, absorb or release power, reduce the risk of overcharging or over-discharging of the battery, maintain the battery SOC balance, and has the effect of reducing the installed power of the battery, increasing the driving power of the whole machine, and stabilizing the engine speed.

[0212] In view of the above technical problems, the embodiments of the present disclosure provide the above-mentioned control method, which can achieve the following effects:

[0213] (1) In the method of the embodiment of the present disclosure, 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 minimize the phenomenon of overcharging or over-discharging of the battery. 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 demand during acceleration and deceleration of the rotary motor, and there is no need to set up an additional braking resistor to consume braking power.

[0214] (2) The ISG motor and engine form a parallel hybrid system to maintain the battery SOC balance and provide power assistance when the power demand is too high to keep the engine within the optimal power range.

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

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

[0217] In the above description, the engine can use the throttle opening to control the speed, and other control methods can also be used to control the speed. In the present disclosure, increasing the output power of the hydraulic pump can be achieved by increasing the output pressure, and it can also be achieved by increasing the output flow.

[0218] Figure 6 6 is a block diagram schematically showing a structure of a vehicle controller according to some embodiments of the present disclosure. The vehicle controller includes a memory 610 and a processor 620. Among them:

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

[0220] The processor 620 is coupled to the memory 610 and can be implemented as one or more integrated circuits, such as a microprocessor or a microcontroller. The processor 620 is used to execute instructions stored in the memory, which can reduce the risk of overcharging or overdischarging the battery power of the hybrid excavator.

[0221] In one embodiment, it is also possible to 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 730. The vehicle controller 700 can also be connected to an external storage device 750 via a storage interface 740 to call 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, the risk of overcharging or over-discharging of the battery power of the hybrid excavator can be reduced by storing data instructions in the memory and processing the instructions through the processor.

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

[0224] In some embodiments, Figure 1 As shown, the control system may also include: an operating lever, a travel pedal and a gear device, which are electrically connected to the vehicle controller respectively; a battery management system, which is electrically connected to the vehicle controller; a battery (power battery), which is electrically connected to the battery management system; a DC-DC converter, which is electrically connected to the battery; a rotary motor controller, which is electrically connected to the battery and the vehicle controller respectively; a rotary motor, which is electrically connected to the rotary motor controller; a rotary mechanism, which is mechanically connected to the rotary motor; an ISG motor controller, which is electrically connected to the battery and the vehicle controller respectively; an ISG motor, which is electrically connected to the ISG motor controller; an engine controller, which is electrically connected to the vehicle controller; an engine, which is electrically connected to the engine controller and mechanically connected to the ISG motor; and a hydraulic pump, which is mechanically connected to the ISG motor.

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

[0226] In some embodiments of the present disclosure, the present disclosure further provides a computer-readable storage medium (e.g., a non-transitory computer-readable storage medium) on which computer program instructions are stored, which are executed by a processor to implement Figures 3 to 5The present invention is a method for performing a method of performing a computer program product in at least one of the embodiments of the present invention. It should be understood by those skilled in the art that the embodiments of the present invention may be provided as methods, devices, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable non-transient storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0227] The present disclosure is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present disclosure. It should be understood that each process and / or block in the flowchart and / or block diagram and the combination of processes and / or blocks in the flowchart and / or block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0228] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0229] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0230] In some embodiments of the present disclosure, a computer program product is further provided. The computer program product includes a computer program or instructions. When the computer program or instructions are executed by a processor, the control method as described above is implemented.

[0231] So far, the present disclosure has been described in detail. In order to avoid obscuring the concept of the present disclosure, some details known in the art are not described. Based on the above description, those skilled in the art can fully understand how to implement the technical solution disclosed here.

[0232] Although some specific embodiments of the present disclosure have been described in detail by way of example, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. A control method for a hybrid excavator, comprising: Obtaining the real-time power of the rotary motor, the maximum charging power allowed by the battery, and the maximum discharging power allowed by the battery; The maximum effective discharge power allowed by the battery is calculated according to the maximum discharge power allowed by the battery, and the maximum effective charging power allowed by the battery is calculated according to the maximum charging power allowed by 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 starter drive generator ISG motor is controlled to enter a power compensation mode so that the ISG motor performs a power generation operation to compensate for the required power of the rotary motor; and 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 a power consumption mode so that the ISG motor performs a driving operation to consume excess power of the rotary motor.

2. The control method according to claim 1, wherein: The maximum effective discharge power P' allowed by the battery mDis =P mDis -P dcdc -P res , Among them, P mDis is the maximum discharge power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

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

4. The control method according to any one of claims 1 to 3, further comprising: When the real-time power of the rotary motor is less than or equal to the maximum effective discharge power allowed by 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 effective charging power allowed by the battery and the real-time power of the rotary motor is less than 0, determining whether the state of charge SOC of the battery is less than an SOC threshold; When the SOC of the battery is less than the SOC threshold, controlling the ISG motor to enter a forced power generation mode so that the ISG motor performs power generation operation to supplement the power of the battery; 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.

5. The control method according to claim 4, wherein: The operation of the ISG motor is controlled according to the real-time power of the hydraulic pump, including: When the real-time power of the hydraulic pump is greater than the upper limit of the optimal power of the engine, controlling the ISG motor to enter a driving assistance 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 upper limit of the engine, the ISG motor is controlled to enter a zero-power following mode, so that the ISG motor follows the operation in a zero-power manner.

6. The control method according to claim 5, further comprising: Calculating the target power of the ISG motor according to different modes of the ISG motor; and An initial target torque of the ISG motor is calculated according to the target power of the ISG motor.

7. The control method according to claim 6, wherein: According to different modes of the ISG motor, the target power of the ISG motor is calculated, including: When the ISG motor is in the power compensation mode, the target power P of the ISG motor is T-ISG P T-ISG =P S -(P mDis -P dcdc -P res ), Among them, P S is the real-time power of the rotary motor, P mDis is the maximum discharge power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

8. The control method according to claim 6, wherein: According to different modes of the ISG motor, the target power of the ISG motor is calculated, including: When the ISG motor is in the power consumption mode, the target power P of the ISG motor is T-ISG P T-ISG =P S -(P mChg -P dcdc +P res ), Among them, P s is the real-time power of the rotary motor, P mChg is the maximum charging power allowed by the battery, P dcdc is the rated power of the DC-DC converter in the hybrid excavator, P res is the reserved power value of the battery.

9. The control method according to claim 6, wherein: According to different modes of the ISG motor, the target power of the ISG motor is calculated, including: When the ISG motor is in the forced power generation mode, the target power P of the ISG motor is T-ISG P T-ISG =P Chg , Among them, P Chg is a preset constant value.

10. The control method according to claim 6, wherein: According to different modes of the ISG motor, the target power of the ISG motor is calculated, including: When the ISG motor is in the driving assist mode, the target power P of the ISG motor is T-ISG P T-ISG =P P -P opt , Among them, P P is the real-time power of the hydraulic pump, P opt is the optimal power upper limit value of the engine.

11. The control method according to claim 6, wherein: According to different modes of the ISG motor, the target power of the ISG motor is calculated, including: When the ISG motor is in zero power following mode, the target power P of the ISG motor is T-ISG is 0.

12. The control method according to claim 6, wherein: The initial target torque T of the ISG motor T-ISG T T-ISG =P T-ISG *9550 / n ISG , Among them, P T-ISG is the target power of the ISG motor, n ISG is the real-time speed of the ISG motor.

13. The control method according to claim 6, further comprising: When the ISG motor is in the power compensation mode, the power consumption mode, the forced power generation mode or the driving assist mode, the initial target torque of the ISG motor is corrected by a fuzzy control algorithm to obtain a 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.

14. The control method according to claim 13, wherein: The initial target torque of the ISG motor is corrected by a fuzzy control algorithm, including: Obtaining a target torque correction amount of the ISG motor based on a target speed and a speed error of the engine through a fuzzy control algorithm; and The corrected target torque T of the ISG motor is obtained according to 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 is the initial target torque of the ISG motor, ΔT is the target torque correction of the ISG motor, T ISG-max is the maximum torque allowed by the ISG motor at the current speed.

15. The control method according to claim 1, further comprising: 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, the output pressure of the hydraulic pump is controlled to increase.

16. The control method according to claim 15, wherein: Controlling to increase the output pressure of the hydraulic pump comprises: Calculate the pressure increment ΔP of the output pressure of the hydraulic pump, Among them, P T-ISG is the target power of the ISG motor, P P is the real-time power of the hydraulic pump, Q is the flow rate of the hydraulic pump, and η is the efficiency of the hydraulic pump.

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

18. The control method according to claim 1, further comprising: Determine the target speed of the rotary motor; Calculating a target torque of the rotary motor according to a target speed of the rotary motor and an actual speed of the rotary motor acquired in real time; and The operation of the rotary electric machine is controlled according to the target torque of the rotary electric machine.

19. The control method according to claim 18, wherein: The target torque T of the rotary motor s T s =min(T i ,T s-max ), in, Wherein, e(t) is the target speed n of the rotary motor. s The actual speed n of the rotary motor collected in real time s-act The real-time difference between p is the proportionality coefficient, K i is the integration coefficient, K d is the differential coefficient, T s-max is the real-time maximum torque allowed by the rotary motor.

20. A vehicle controller, comprising: Memory; as well as A processor coupled to the memory, wherein the processor is configured to execute the control method according to any one of claims 1 to 19 based on instructions stored in the memory.

21. A control system for a hybrid excavator, comprising: The vehicle controller as claimed in claim 20.

22. The control system of claim 21, further comprising: The operating lever, the travel pedal and the gear device are electrically connected to the vehicle controller respectively; 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 the battery and the vehicle controller respectively; A rotary motor electrically connected to the rotary motor controller; A slewing mechanism, mechanically connected to the slewing motor; An ISG motor controller is electrically connected to the battery and the vehicle controller respectively; 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 is mechanically connected to the ISG motor.

23. A hybrid excavator, comprising: A control system as claimed in claim 21 or 22.

24. A computer-readable storage medium having computer program instructions stored thereon, wherein the computer program instructions, when executed by a processor, implement the control method according to any one of claims 1 to 19.

25. A computer program product, comprising a computer program or instructions, which implement the control method according to any one of claims 1 to 19 when executed by a processor.

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