CN113565164A

CN113565164A - Loader control system, loader, and loader control method

Info

Publication number: CN113565164A
Application number: CN202111126321.2A
Authority: CN
Inventors: 魏加洁; 沈勇; 韩嫔; 王小虎; 范小童; 李夏宇
Original assignee: Science and Technology Branch of XCMG
Current assignee: Science and Technology Branch of XCMG
Priority date: 2021-09-26
Filing date: 2021-09-26
Publication date: 2021-10-29

Abstract

The invention discloses a loader control system, a loader and a loader control method, relates to the field of engineering machinery, and aims to improve the performance of the loader. The loader control system includes: the engine is configured to provide rotational kinetic energy; the ISG motor is in driving connection with the engine; the ISG motor comprises a generator working mode and a motor working mode; the generator is in driving connection with the ISG motor; the controller is electrically connected with the generator and the ISG motor and is in communication connection with the engine, and the controller is also electrically connected with the traction motor. The energy storage device is electrically connected with the controller. The lifting system comprises a hydraulic pump and a lifting cylinder, and the hydraulic pump is connected with the lifting cylinder through a hydraulic oil circuit. The hydraulic pump is connected with the engine through the generator and the ISG motor in a driving mode. The driving assembly comprises a traction motor and a speed reducer which are in driving connection. The generator is electrically connected with the traction motor through the controller so as to transmit electric energy to the traction motor. According to the technical scheme, the output power of the loader is increased.

Description

Loader control system, loader, and loader control method

Technical Field

The invention relates to the field of engineering machinery, in particular to a loader control system, a loader and a loader control method.

Background

When the loader is in heavy load operation, a driver often steps on an accelerator with a big foot in order to improve the operation efficiency, and a movable arm is lifted, namely, the loader adopts a combined action operation mode: namely, the boom is lifted while walking. In this operation mode, power consumption is high. If the power selection of the engine is smaller, the rotating speed of the engine is too high, namely the rotating speed is reduced too fast, and when the rotating speed of the engine is reduced to a certain value, the engine is easy to stall; on the other hand, too much reduction of the rotation speed of the engine can cause the lifting of the movable arm cylinder to be too slow, the walking speed is also influenced, and the comprehensive operation efficiency of the whole machine is not high.

Therefore, in order to fully satisfy the heavy-load combined operation condition, the power selection of the engine generally has more margin, namely, the engine with high power is selected to increase the power of the engine.

The invention finds that the related art has the following problems: the selection of a high-power engine can lead to higher cost of the engine, and the cost of an aftertreatment system and a heat dissipation system matched with the engine, vibration reduction of the engine of the whole engine, a shield and the like is increased; in addition, the problems of large oil consumption, large noise and the like of the whole machine exist, and the comprehensive use cost of the whole machine is increased.

Disclosure of Invention

The invention provides a loader control system, a loader and a loader control method, which are used for improving the output power of the loader on the premise of not increasing the power of an engine of the loader.

An embodiment of the present invention provides a loader control system, including:

an engine configured to provide rotational kinetic energy;

the ISG motor is in driving connection with the engine; the ISG motor comprises a generator working mode and a motor working mode;

the generator is in driving connection with the ISG motor;

a controller electrically connected to both the generator and the ISG motor, the controller communicatively connected to the engine, the controller configured to switch an operating mode of the ISG motor;

the energy storage device is electrically connected with the controller; when the ISG motor is in a generator working mode, the energy storage device is charged through the ISG motor; when the ISG motor is in a motor working mode, the energy storage device provides electric energy for the ISG motor through the controller;

the lifting system comprises a hydraulic pump and a lifting cylinder; the hydraulic pump is connected with the lifting cylinder through a hydraulic oil circuit; the engine is in driving connection with the hydraulic pump through the ISG motor and the generator; and the number of the first and second groups,

the driving assembly comprises a traction motor and a speed reducer which are in driving connection; the generator is electrically connected with the traction motor through the controller so as to transmit electric energy to the traction motor.

In some embodiments, the controller comprises:

a central controller in communication with the engine to control an output power of the engine;

an ISG controller communicatively coupled to the central controller, the ISG controller further electrically coupled to the ISG motor, the ISG controller configured to switch an operating mode of the ISG motor between a generator operating mode and a motor operating mode;

the generator controller is in communication connection with the central controller and is also electrically connected with the generator;

the energy storage device controller is in communication connection with the central controller and is also electrically connected with the energy storage device; and the number of the first and second groups,

and the traction motor controller is in communication connection with the central controller and is also electrically connected with the traction motor.

In some embodiments, the lift system further comprises:

a handle configured to output a lift signal to control the lift cylinder;

a multi-way valve disposed in an oil path of the hydraulic pump;

the hydraulic controller is in communication connection with the handle to adjust a working angle signal of the handle; the hydraulic controller is also in communication connection with the multi-way valve so as to control the displacement of a valve core of the multi-way valve; and the number of the first and second groups,

and the hydraulic controller is in communication connection with the central controller through the CAN.

In some embodiments, the loader control system further comprises:

an electronic throttle pedal electrically connected to the central controller, the controller configured to control an output power of the traction motor according to an angle signal of the throttle pedal.

In some embodiments, the traction motors include four, each of the traction motors being individually configured with one of the traction motor controllers.

In some embodiments, the central controller and the ISG controller are configured to perform the following operations:

the central controller judges the relationship between the rated power of the engine and the power required by the current load;

if the power required by the load is smaller than the rated power of the engine, the central controller sends a signal for switching the ISG motor working mode to the generator working mode to the ISG controller, and the ISG controller switches the ISG motor working mode to the generator working mode; and if the power required by the load is greater than or equal to the rated power of the engine, the central controller sends a signal for switching the ISG motor working mode to the ISG controller, and the ISG controller switches the ISG motor working mode to the motor working mode.

In some embodiments, when the ISG motor is in a generator mode of operation:

the power transmission path is: the engine drives the ISG motor and the generator to rotate;

the power generation path is as follows: the engine drives the ISG motor to rotate, and the ISG motor transmits the generated electric energy to the energy storage device after the electric energy is converted by the controller.

In some embodiments, when the ISG motor is in a generator mode of operation:

the transmission process of the walking kinetic energy is as follows: the generator rotates to generate electricity, and the electric energy sent by the generator is transmitted to the traction motor through the controller.

In some embodiments, when the ISG motor is in a motoring mode:

the power transmission path is: the energy storage device drives the ISG motor to rotate, and the engine and the ISG motor jointly drive the hydraulic pump to rotate;

the power consumption path is as follows: the energy storage device transmits electric energy to the ISG motor through the controller so as to drive the ISG motor to rotate.

In some embodiments, when the ISG motor is in a motoring mode:

the transmission process of the walking kinetic energy is as follows: the generator rotates to generate electricity, and the electric energy sent by the generator is transmitted to the speed reducer through the controller.

In some embodiments, the power required by the load is less than the rated power of the engine under various conditions: the loader normally runs, the loader is lifted independently, and the loader performs combined working condition operation that the loader travels while lifting, and both travels and lifts do not reach a limit state.

In some embodiments, the power required by the load is greater than or equal to the rated power of the engine under various conditions: the loader performs combined working condition operation of lifting while walking, and at least one of walking and lifting reaches a limit state.

In some embodiments, the loader control system further comprises:

a transfer case disposed between the generator and the hydraulic pump, the transfer case being configured to receive the rotational power output from the engine and the ISG motor in a motor operation mode and to transmit to the hydraulic pump.

The embodiment of the invention also provides a loader which comprises the loader control system provided by any technical scheme of the invention.

The embodiment of the invention also provides a control method of the loader, which comprises the following steps:

judging the relation between the rated power of the engine and the power required by the current load;

and if the power required by the load is greater than or equal to the rated power of the engine, switching the ISG motor to a motor working mode, and jointly driving the hydraulic pump and the traction motor to act by the ISG motor and the engine.

In some embodiments, the loader control method further comprises the steps of:

if the power required by the load is smaller than the rated power of the engine, the ISG motor is switched to a generator working mode, the engine drives the hydraulic pump, the ISG motor and the traction motor to act, and the electric energy generated by the ISG motor is output to the energy storage device to be stored.

The loader control system provided by the technical scheme is provided with the engine, the ISG motor, the generator, the controller, the energy storage device, the lifting system and the driving assembly. The ISG motor has two modes of operation: generator operating mode and motor operating mode. If the power required by the load is less than the rated power of the engine, the engine has enough driving capability, and the driving shafts of the ISG motor and the generator driven by the engine and the generator synchronously rotate. The rotary power has the following three purposes: firstly, when lifting is needed, the rotating power is transmitted to a hydraulic pump to drive the hydraulic pump to work; secondly, when the loader needs to walk, the rotary power is used for driving a generator to generate electricity, and the generated electricity is converted by a controller and then is transmitted to a traction motor so as to realize the electrically driven walking of the loader; thirdly, the engine can synchronously drive the ISG motor in the working mode of the generator, the ISG motor generates electricity, and the generated electric energy is converted by the controller and then is transmitted to the energy storage device for storage.

If the power required by the load is larger than or equal to the rated power of the engine, the engine does not have enough driving capability, the ISG motor is in a motor working mode at the moment, and the engine and the ISG motor jointly provide rotating power. The rotary power has the following two purposes: firstly, when lifting is needed, the rotating power is transmitted to a hydraulic pump to drive the hydraulic pump to work; secondly, when walking is needed, the rotation power is used for driving the generator to generate electricity, and the generated electricity is converted by the controller and then transmitted to the traction motor so as to realize the electrically driven walking of the loader. Under the condition, the energy required by the rotation of the ISG motor comes from the energy storage device, and the stored electric energy is converted by the energy storage device through the controller and then is transmitted to the ISG motor for use.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the invention without limiting the invention. In the drawings.

Fig. 1 is a schematic diagram of a principle of a loader control system according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a controller principle of a loader control system according to an embodiment of the present invention.

Fig. 3a is a power transmission path of an ISG motor in a motor operation mode in the loader control system according to the embodiment of the present invention.

Fig. 3b is a diagram illustrating a power transmission path of an ISG motor in a generator operating mode in the loader control system according to the embodiment of the present invention.

Fig. 3c is a transmission path of the generator to transmit electric energy to the traction motor in the loader control system according to the embodiment of the present invention.

Fig. 4 is a flowchart illustrating a control method of a loader according to an embodiment of the present invention.

Detailed Description

The technical solution provided by the present invention is explained in more detail with reference to fig. 1 to 4.

The embodiment of the invention provides a loader control system which comprises an engine 3, an ISG motor 5, a generator 6, a controller 4, an energy storage device 2, a lifting system and a driving assembly. The engine 3 is configured to provide rotational kinetic energy. The ISG motor 5 is in driving connection with the engine 3. The ISG motor 5 includes a generator operating mode and a motor operating mode. The generator 6 is in driving connection with the ISG motor 5. The controller 4 is electrically connected with the generator 6 and the ISG motor 5. The controller 4 is configured to switch an operation mode of the ISG motor 5. The energy storage device 2 is electrically connected to the controller 4. Wherein, when the ISG motor 5 is in the generator operating mode, the energy storage device 2 is charged via the ISG motor 5. When the ISG motor 5 is in the motor operation mode, the energy storage device 2 supplies electric energy to the ISG motor 5 via the controller 4. The lifting system comprises a hydraulic pump 10 and a lifting cylinder 13, and the hydraulic pump 10 is connected with the lifting cylinder 13 through a hydraulic oil circuit; the hydraulic pump 10 is in driving connection with the engine 3 through the generator 6 and the ISG motor 5. The driving assembly comprises a traction motor 16 and a speed reducer 15 which are in driving connection; the generator 6 is electrically connected to the traction motor 16 through the controller 4 to deliver electrical power to the traction motor 16.

Here, the engine 3 may employ an existing device. For example, if the maximum power required at the limit of the loader is 450KW, an engine 3 rated for 400KW may be used, the remaining 50KW of energy being provided by the ISG motor 5. Therefore, by adopting the technical scheme of the embodiment of the invention, the engine 3 with smaller power can be selected, and the requirement of larger power of the whole loader can be realized. And because the power provided by the engine 3 and the ISG motor 5 together is enough, various actions (normal running, boom lifting and the like) of the loader can be carried out at a speed determined according to actual conditions, and the speed is controlled by a driver, so that the phenomenon of low working efficiency caused by slow action due to insufficient power is reduced or even avoided, and the comprehensive working efficiency of the whole machine is higher.

Here, the ISG (Integrated Starter and Generator, abbreviated as ISG) motor 5 is an Integrated Starter and Generator.

The ISG motor 5 is an electric power generating integrated machine, and can be used as a generator or a motor. Herein, the switching of the two operation modes of the ISG motor 5 is related to the load power of the loader.

If the power required by the load is greater than or equal to the rated power of the engine 3, the ISG motor 5 is in the motor operation mode. In the motor operation mode, the ISG motor 5 and the engine 3 together drive the generator 6 and the hydraulic pump 10 to operate, so as to realize the normal running of the loader and the lifting operation of the hydraulic cylinder.

If the power required by the load is less than the rated power of the engine 3, the ISG motor 5 is in the generator operation mode. In the generator operation mode, the engine 3 drives the generator 6 and the hydraulic pump 10 to operate alone to perform one of normal travel of the loader, a lifting operation of the hydraulic cylinder, or a combined operation in a non-limit state. In this mode, the engine 3 also drives the ISG motor 5 to generate power, and the electric energy generated by the ISG motor 5 is stored in the energy storage device 2 and is provided to the ISG motor 5 by the energy storage device 2 when the ISG motor 5 needs to be used as a motor working mode.

For ease of understanding, the following description is made herein of the manner in which components may be connected as may be referred to hereinafter: herein, the communication connection is for exchanging data between the controller and the controller or between the controller and the CAN. The ISG motor 5 and the generator 6 are used as power executing elements and do not have the function of communication connection, because parameters such as torque, rotating speed and the like of the motor are not collected by the motor, the parameters are converted into kinetic parameters according to voltage, current and the like output by a corresponding controller and are sent to the controller through a sensor, namely the controller obtains the parameters of the motor, and the motor does not need to obtain the parameters of the controller. Therefore, wire harness connections, i.e., electrical connections, are used between the ISG motor 5 and the ISG controller 4B, between the generator 6 and the generator controller 4C, and between the traction motor 16 and the traction motor controller 4D. And the energy storage device 2 also has no communication function, the energy storage device 2 is also connected, i.e., electrically connected, to an energy storage device controller 4E described later by a wire harness.

The communication link between the VCU and the engine 3 is such that the engine 3 comprises an electronic control unit ECU. The handle 11 is also in communication with the hydraulic control unit 9, since the handle 11 has a CAN line. The electronic accelerator pedal 1 has no CAN wire and is also connected with the VCU by adopting a wire harness. So, herein, the use of a wire harness connection is collectively referred to as an electrical connection. And a component having both components with communication functions, if connection is required, a communication connection is used.

Here, the controller 4 is electrically connected to the generator 6 and the ISG motor 5 by a wire harness. The wire harness includes a control wire (thin wire), an electric wire (thick wire), a cable, an optical fiber, and the like. The controller 4 is in communication connection with the engine 3 to realize signal interaction.

The energy storage device 2 is electrically connected with the controller 4, specifically, electrically connected through a wire harness. The energy storage device 2 includes: lithium batteries, capacitors, supercapacitors, and other devices that can store and release electrical energy, among others.

The generator 6 is an alternator, including existing alternators, permanent magnet generators, reluctance generators, etc., and in some embodiments, permanent magnet synchronous generators are employed. After the generator 6 generates power, the power is converted, regulated and inverted by a controller 4, specifically a generator controller 4C, VCU (central controller 4A) and a traction motor controller 4D (described later), and then electric energy is output to a traction motor 16 of the drive assembly, and the traction motor 16 drives a speed reducer 15 to travel.

The hydraulic pump 10 is a variable electrically controlled hydraulic pump, and the displacement of the pump can be adjusted according to an input electric signal. The multi-way valve 12 is an electrically controlled multi-way valve, and can adjust the opening of a valve core according to an input electrical signal. The magnitude of the load is positively correlated with the output of the hydraulic pump 10, and is not greatly correlated with the angle of the handle 11 described later. The angle of the handle 11 may or may not be maximized when the loader is unloaded, depending on the actual operation of the driver.

Traction motor 16 is an AC motor, including conventional AC motors, PMSM, reluctance motors, and the like, and in some embodiments, a PMSM is used.

The drive assembly may include, in addition to traction motor 16 and reducer 15, sensors 14 that send signals of speed, torque, power, current, voltage, etc. to controller 4. In some embodiments, the loader has four sets of wheels, each set of wheels being individually equipped with a traction motor 16, each traction motor 16 being individually equipped with a speed reducer 15, and being individually equipped with a traction motor controller 4D. Each traction motor controller 4D is individually equipped with a sensor 14, thus realizing a four-wheel independent electric drive configuration of the loader.

Referring to fig. 1, in some embodiments, the loader control system further includes a transfer case 8, the transfer case 8 being disposed between the generator 6 and the hydraulic pump 10. The transfer case 8 is configured to receive the rotational power output from the engine 3 and the ISG motor 5 described below in the motor operation mode, and to transmit it to the hydraulic pump 10. The transfer case 8 may take an existing configuration.

Referring to fig. 1 and 2, the controller 4 includes a central control unit (VCU) 4A, ISG controller 4B, a generator controller 4C, an energy storage device controller 4E, and a traction motor controller 4D.

Referring to fig. 1 and 2, the central controller 4A is communicatively connected to the engine 3 to control the output power of the engine 3. The VCU also automatically detects the output power, torque and speed of the engine 3. The ISG controller 4B is communicatively connected to the central controller 4A. The ISG controller 4B is also electrically connected to the ISG motor 5, specifically by a wire harness. The ISG controller 4B is configured to switch the operation mode of the ISG motor 5 between a generator operation mode and a motor operation mode. The generator controller 4C is in communication connection with the central controller 4A, and the generator controller 4C is also electrically connected with the generator 6, specifically, by a wire harness. Energy storage device controller 4E is in communication with central controller 4A, and energy storage device controller 4E is also electrically connected to energy storage device 2. The traction motor controller 4D is in communication connection with the central controller 4A, and the traction motor controller 4D is also electrically connected with the traction motor 16, specifically, by a wire harness.

Referring to fig. 1 and 2, the specific connection is as follows.

(1) The input terminal connection relation of VCU is: input terminal u0 is connected to the n1 terminal of CAN7, input terminal u1 is connected to the output terminal of first sensor 14as, input terminal u2 is connected to the output terminal of second sensor 14bs, input terminal u3 is connected to the output terminal of third sensor 14cs, input terminal u4 is connected to the output terminal of fourth sensor 14ds, input terminal u5 is connected to the output terminal E2 of energy storage device controller 4E, input terminal u6 is connected to the output terminal of electronic oil door pedal 1, input terminal u7 is connected to the output terminal of engine 3, input terminal u8 is connected to the output terminal g2 of ISG controller 4B, and input terminal u9 is connected to the output terminal f2 of motor controller 4C.

(2) The output terminal connection relation of VCU is: the output terminal u0 is connected to the n1 terminal (u 0 is both an input terminal and an output terminal) of the CAN7, the output terminal r0 is connected to the f1 input terminal of the motor controller 4C, the output terminal r1 is connected to the t0 input terminal of the traction motor controller 4D, the output terminal r2 is connected to the E0 input terminal of the energy storage device controller 4E, the output terminal r3 is connected to the input terminal of the engine 3, and the output terminal r4 is connected to the g1 input terminal of the ISG controller 4B.

(3) The input terminal connection relationship of the hydraulic controller 9 is as follows: the input terminal h0 of the hydraulic controller 9 is connected with the output terminal of the handle 11 to receive the angle signal output by the handle 11.

(4) The output terminal connection relationship of the hydraulic controller 9 is as follows: the output terminal h1 of the hydraulic controller 9 is connected with the input terminal of the hydraulic pump 10, the output terminal h2 of the hydraulic controller 9 is connected with the input terminal of the multi-way valve 12, and the output terminal h3 of the hydraulic controller 9 is connected with the n0 input terminal of the CAN 7.

(5) The input terminal connection relationship of the ISG controller 4B is: the ISG controller 4B input terminal g0 is connected to the output terminal of the ISG motor 5, and the ISG controller 4B input terminal g1 is connected to the r4 output terminal of the VCU.

(6) The output terminal connection relationship of the ISG controller 4B is: the ISG controller 4B output terminal g2 is connected to the u8 input terminal of the VCU, and the ISG controller 4B output terminal g3 is connected to the input terminal of the ISG motor 5.

(7) The input terminal connection relationship of the generator controller 4C is: the generator controller 4C input terminal f0 is connected to the output terminal of the generator 6, and the generator controller 4C input terminal f1 is connected to the r0 output terminal of the VCU.

(8) The output terminal connection relationship of the generator controller 4C is: the generator controller 4C output terminal f2 is connected to the u9 input terminal of the central controller (VCU) 4A.

(9) The input terminal connection relationship of the traction motor controller 4D is: the traction motor controller 4D input terminal t0 is connected to the r1 output terminal of the VCU.

(10) The output terminal connection relationship of the traction motor controller 4D is: the output terminal t1 of the traction motor controller 4D is connected to the input terminal of the first traction motor 16a, the output terminal t2 of the traction motor controller 4D is connected to the input terminal of the second traction motor 16b, the output terminal t3 of the traction motor controller 4D is connected to the input terminal of the third traction motor 16c, and the output terminal t4 of the traction motor controller 4D is connected to the input terminal of the fourth traction motor 16D.

(11) The input terminal connection relationship of the energy storage device controller 4E is: the input terminal E0 of the energy storage device controller 4E is connected with the r2 output terminal of the VCU, and the input terminal E1 of the energy storage device controller 4E is connected with the output terminal of the energy storage device 2.

(12) The output terminal connection relationship of the energy storage device controller 4E is: the output terminal e2 is connected to the u5 input terminal of the VCU, and the output terminal e3 is connected to the input terminal of the energy storage device 2.

With continued reference to fig. 1 and 2, the output terminal of the first traction motor 16a is connected to the input terminal of the first sensor 14a, the output terminal of the second traction motor 16b is connected to the input terminal of the second sensor 14b, the output terminal of the third traction motor 16c is connected to the input terminal of the third sensor 14c, and the output terminal of the fourth traction motor 16d is connected to the input terminal of the fourth sensor 14 d.

With continued reference to fig. 1 and 2, the lift system further includes a handle 11, a multiplex valve 12, a hydraulic controller 9, and a CAN 7. The handle 11 is configured to output a lift signal to control the motion of the lift cylinder 13. The multi-way valve 12 is provided in an oil passage of the hydraulic pump 10. The hydraulic controller 9 is in communication with the handle 11 to detect an operating angle signal of the handle 11. The hydraulic controller 9 is also electrically connected to the multiplex valve 12 to control the spool displacement of the multiplex valve 12. The hydraulic controller 9 is connected in communication with the central controller 4A via CAN 7.

Specifically, the input terminal connection relationship of the CAN7 is as follows: the CAN7 input terminal n0 is connected to the h3 output terminal of the hydraulic controller 9, and the CAN7 input terminal n1 is connected to the u0 output terminal of the VCU.

The output terminal connection relation of the CAN7 is as follows: the CAN7 output terminal n1 is connected to the u0 input terminal of the VCU (connected to the VCU, n1 is the same input and output terminal).

The status information of the hydraulic pump 10, the multiplex valve 12, the handle 11, etc. is transmitted to the CAN7 through the hydraulic controller 9, and displayed and monitored in the CAN 7. After the hydraulic controller 9 sends a signal to the CAN7, the VCU (central controller 4A) reads the signal through the CAN7, detects the power, torque and rotation speed of the engine 3, and starts the ISG motor 5 to output additional power when the power is greater than or equal to the rated power.

The state parameters of the engine 3, the generator 6, the ISG motor 5, the traction motor 16 of the drive assembly, the running of the whole machine and the like send signals to the CAN7 through the VCU (central controller 4A), and the signals are displayed and monitored in the CAN 7. The relevant signals CAN be conveniently read by the driver through the CAN 7.

The ISG motor 5 outputs extra power increment (realized by the energy storage device controller 4E, the VCU and the ISG controller 4B), namely the ISG motor 5 and the engine 3 output power to the whole machine together, so that the rotating speed of the engine 3 is improved or maintained, the output of the engine 3 is ensured to be close to or equal to rated power, the working efficiency of the whole machine is improved, and the oil consumption of the whole machine is reduced. Moreover, the model selection power of the engine 3 is reduced, and the comprehensive use cost of a user is reduced; during heavy load operation, the rotation speed of the engine 3 can be kept at a certain rigidity, so that the rotation speed of the engine 3 is basically kept unchanged or is improved to a certain degree. Here, the rotation speed of the engine 3 is maintained substantially constant, which means that the rotation speed is maintained in the range of a ± 3%, where a is the rotation speed corresponding to the engine rated power. The speed response of the engine 3 (response on the order of 0.5 seconds) lags behind the speed response of the ISG motor (response on the order of 50 milliseconds), resulting in fluctuations in the speed of the engine 3. The rotating speed of the engine 3 is maintained in the interval of A +/-3%, which shows that the rotating speed of the engine 3 keeps certain rigidity.

Referring to fig. 1, the backward operation of the handle 11 is a boom raising, the forward operation is a boom lowering, and the angle signal of the handle 11 is positively correlated (or proportional) to the strength of the signals sent by the hydraulic controller 9 to the hydraulic pump 10 and the multi-way valve 12, that is, the opening degrees of the spools of the hydraulic pump 10 and the multi-way valve 12 are positively correlated, that is, the flow rate is positively correlated, that is, the boom raising speed is positively correlated.

In practical application, when the movable arm is lifted to the top, a driver loosens the handle 11, the handle 11 is reset, the hydraulic lifting action is stopped, the whole machine is driven to run only, the VCU (central control unit 4A) sends a power generation signal to the energy storage device 2 and the ISG motor 5, and the engine 3 drives the ISG motor 5 to charge the energy storage device 2. A driver lifts a movable arm through a handle 11, after detecting a lifting signal, a hydraulic controller 9 outputs a proportional signal to a hydraulic pump 10 and a multi-way valve 12 simultaneously, the output of the displacement of the hydraulic pump 10, the opening of a valve core of the multi-way valve 12 and the angle of the handle 11 are positively correlated, and the hydraulic pump 10 supplies oil to a lifting cylinder 13 through the multi-way valve 12.

With continued reference to fig. 1 and 2, the loader control system further includes an electronic throttle pedal 1, the electronic throttle pedal 1 being electrically connected to a central controller 4A, the controller 4 being configured to control the output power of the traction motor 16 in accordance with an angle signal of the electronic throttle pedal 1. The angle of the electronic accelerator pedal 1 is positively correlated (or proportional) to the strength of a signal output from the VCU (central controller 4A) to the traction motor 16 and the amount of power output from the traction motor 16.

Various operations performed by the controller 4 are described below.

In some embodiments, the central controller 4A and the ISG controller 4B are configured to perform the following operations: first, the central controller 4A judges the relationship between the rated power of the engine 3 and the power required by the current load; secondly, if the power required by the load is less than the rated power of the engine 3, the central controller 4A sends a signal for switching the working mode of the ISG motor 5 to the generator working mode to the ISG controller 4B, and the ISG controller 4B switches the working mode of the ISG motor 5 to the generator working mode; if the power required by the load is greater than or equal to the rated power of the engine 3, the central controller 4A sends a signal for switching the operation mode of the ISG motor 5 to the motor operation mode to the ISG controller 4B, and the ISG controller 4B switches the operation mode of the ISG motor 5 to the motor operation mode.

In some embodiments, when the ISG motor 5 is in the generator mode of operation, the power transmission path is: the engine 3 drives the ISG motor 5 and the generator 6 to rotate. In this mode, the power generation path is: the engine 3 drives the ISG motor 5 to rotate, and the ISG motor 5 transmits the generated electric energy to the energy storage device 2 after being converted by the controller 4.

Specifically, the power generation path is a process in which the engine 3 drives the ISG motor 5 to charge the energy storage device 2, and the process is as follows: the engine 3 drives the ISG motor 5 to generate power, the ISG motor 5 converts alternating current into direct current through the ISG controller 4B, and sends the direct current to the energy storage device controller 4E through the VCU (central controller 4A), and the energy storage device controller 4E inputs the direct current into the energy storage device 2 for storage. I.e. in this case the common power output is stopped and the energy storage means 2 is charged.

The other transmission path is as follows: the ISG controller 4B may also directly send the converted dc power to the energy storage device controller 4E without passing through the VCU, which only outputs control signals to the ISG controller 4B and the energy storage device controller 4E.

In some embodiments, when the ISG motor 5 is in the generator operation mode, the walking kinetic energy is transferred as follows: the generator 6 is rotated to generate electricity, and the electric energy sent by the generator 6 is transmitted to the traction motor 16 via the controller 4.

In some embodiments, when the ISG motor 5 is in the motor operation mode, the power transmission path is: the energy storage device 2 drives the ISG motor 5 to rotate, and the engine 3 and the ISG motor 5 jointly drive the hydraulic pump 10 to rotate.

The power consumption path is as follows: the energy storage device 2 transmits the converted electric energy to the ISG motor 5 through the controller 4 to drive the ISG motor 5 to rotate.

In some embodiments, when the ISG motor 5 is in the motor operation mode, the walking kinetic energy is transferred as follows: the generator 6 is rotated to generate electricity, and the electric energy sent by the generator 6 is transmitted to the traction motor 16 via the controller 4.

It has been described above that the two operating modes of the ISG motor 5 are related to the power required by the load, which is less than the rated power of the engine 3, in each of the following cases: the loader runs normally, the loader lifts alone, and the loader carries out combined working condition operation that the loader lifts and walks simultaneously, and both the walking and the lifting do not reach the limit state.

The power required by the load is greater than or equal to the rated power of the engine 3 in each of the following situations: the loader performs combined working condition operation of lifting while walking, and at least one of walking and lifting reaches a limit state.

Specific examples are described below.

Referring to fig. 1 and 2, the loader control system generally includes three types of connections, namely oil connections, electrical connections and mechanical connections.

First, the manner of connecting the oil passages of the hydraulic system will be described. The oil source is respectively connected with the large cavity and the small cavity of the two lifting cylinders 13 through the hydraulic pump 10 and the multi-way valve 12, and the small cavity of the lifting cylinder 13 is connected back to the oil tank through the multi-way valve 12.

For details of the circuit connection, reference is made to the connection relationship of the respective controllers 4, which is only described in a general way here. The circuit connection includes two types of electrical connection and communication connection. An input port of the VCU (central controller 4A) is communicatively connected to the engine 3, the ISG controller 4B, the generator controller 4C, CAN7, the traction motor controller 4D, and the energy storage device controller 4E, respectively. The input port of the VCU (central controller 4A) is also electrically connected to the sensor 14 of the drive assembly and the electronic accelerator pedal 1. A plurality of output ports of the VCU (central controller 4A) are communicatively connected to the engine 3, the ISG controller 4B, the generator controller 4C, CAN7, the traction motor controller 4D, and the energy storage device controller 4E, respectively.

The input and output ports of the ISG controller 4B are simultaneously connected with an ISG motor 5; an input port of the generator controller 4C is connected with the generator 6.

An output port of the traction motor controller 4D is connected to a traction motor 16.

The input and output ports of the energy storage device controller 4E are simultaneously connected to the energy storage device 2.

The input port of the hydraulic controller 9 is connected with the handle 11, the output port is connected with the CAN7, the hydraulic pump 10 and the multi-way valve 12.

The implementation of the mechanical connection is described below. The engine 3, the ISG motor 5, the generator 6 and the transfer case 8 are connected through a coupler or a transmission shaft, and the transfer case 8 is connected with the hydraulic pump 10 through a spline. When the coupling connection is adopted, the axes of the flywheel of the engine 3, the ISG motor 5, the generator 6 and the input shaft of the transfer case 8 are superposed. If the transmission shaft is connected, the flywheel of the engine 3, the ISG motor 5, the generator 6 and the input shaft of the transfer case 8 can be in driving connection without being required to be coaxial.

The operation modes under various conditions are described below.

The whole machine has the following working modes: independent walking, independent lifting (including heavy-load lifting and non-heavy-load lifting), and simultaneous walking and lifting. When the vehicle travels and lifts simultaneously, the power of the engine 3 may approach or be equal to the rated power when the lifting and traveling reach the parameters corresponding to the limit state, according to the load-bearing condition and the traveling parameters. In other situations, the power of the engine 3 can meet the requirement when a driver independently performs one of the heavy-load lifting action of the whole machine and the driving of the whole machine to walk. And under the combined working condition that the walking and the lifting are simultaneously carried out but at least one of the walking and the lifting does not reach the limit state, the power of the engine 3 can meet the requirement.

Both the two actions are performed simultaneously, and in the limit state, the power of the engine 3 is exerted to the maximum, the power of the engine 3 is close to or equal to the rated power, but the whole loader obviously has insufficient power, and therefore walking is slow, lifting is weak and the like. At this time, the ISG motor 5 needs to be started to perform additional power output, that is, the engine 3 and the ISG motor 5 jointly perform power output on a load, and the power of the engine 3 reaches the rated power. I.e. the engine 3 is kept in the vicinity of the rated power value, e.g. in the range of plus or minus 3%, while the part of the load required to exceed the power of the engine 3 is met by the ISG motor 5.

According to the fact that whether the power of the engine 3 reaches the rated power or not under each working condition, the working conditions are divided into two categories, the first category is that the required power is smaller than the rated power of the engine 3, at the moment, the ISG motor 5 serves as a generator, and the generated electric energy is transmitted to the energy storage device 2 to be stored. The second is that the required power is close to or up to the rated power of the engine 3, where the ISG motor 5 acts as a motor and the energy storage device 2 provides electrical energy to the ISG motor 5.

The first type of situation is: when the whole works normally. At this time, the corresponding working conditions are as follows: the driver independently carries out heavy-load lifting action, or drives the whole machine to walk under the condition of load or no load.

When the VCU (central controller 4A) detects that the power of the engine 3 is smaller than the rated power, it indicates that the load is no load, light load, or non-combined operation, or the degree of the combined operation mode is not large, i.e., the accelerator is slightly stepped on, or the handle angle for lifting the boom is small, and the like, at this time, the power of the engine 3 is not exerted to the maximum, so the ISG does not participate in power output, but charges the energy storage device 2 in a manner of power generation by a generator.

Specifically, the method comprises the following steps: the engine 3 drives the ISG motor 5 to generate power, the ISG motor 5 converts alternating current into direct current through the ISG controller 4B, and sends the direct current to the energy storage device controller 4E through the VCU (central controller 4A), and the energy storage device controller 4E inputs the direct current into the energy storage device 2 for storage. Another possible way is: the engine 3 drives the ISG motor 5 to generate electricity, the ISG motor 5 converts alternating current into direct current through the ISG controller 4B, the ISG controller 4B directly sends the converted direct current to the energy storage device controller 4E, and the energy storage device controller 4E inputs the direct current into the energy storage device 2 for storage. This mode does not pass through the VCU (central controller 4A).

In the first case, it is described in the following by dividing into three cases of normal driving, heavy-load walking transportation alone, and lifting operation alone.

1. When the whole machine normally runs: the engine 3 drives the ISG motor 5, the generator 6, the transfer case 8 and the hydraulic pump 10 to run. The ISG motor 5 charges the energy storage device 2 through the ISG controller 4B, VCU (central controller 4A) and the energy storage device controller 4E; the generator 6 transmits electric energy to the driving assembly through the generator controller 4C, VCU (central controller 4A) and the traction motor controller 4D to drive the whole machine to walk.

The method specifically comprises the following steps: the VCU detects that the power of the engine 3 is smaller than the rated power, outputs a command to the ISG controller 4B through the r4 terminal and the g1 terminal, the ISG controller 4B outputs a power generation command to the ISG motor 5 through the g3 terminal, the ISG motor 5 outputs three-phase alternating current to the g0 terminal of the ISG controller 4B through the output terminal, and the ISG controller 4B converts the alternating current into direct current through its converter, and inputs the direct current into the energy storage device 2 through the ISG controller 4B, i.e., the ISG controller 4B output terminal g2, the VCU input terminal u8, the VCU output terminal r2, the energy storage device controller 4E input terminal E0, and the energy storage device controller 4E output terminal E3, and stores the energy.

The generator 6 transmits electric energy to the driving assembly through the generator controller 4C, VCU and the traction motor controller 4D to drive the whole machine to walk.

The method specifically comprises the following steps: the VCU requests the generator controller 4C to output an electric power command through the r0 terminal and the f1 terminal, the generator 6 outputs three-phase alternating current to the f0 terminal of the generator controller 4C through the output terminal, the generator controller 4C converts the alternating current into direct current through its converter, and outputs the direct current through the output terminal f2, the VCU terminal u9, the VCU terminal r1, the traction motor controller 4D terminal t0, and inputs the direct current to the traction motor controller 4D, the traction motor controller 4D converts the direct current into alternating current through its inverter, and outputs the alternating current through the terminal 1 to the first traction motor 16a, outputs the alternating current through the terminal t2 to the second traction motor 16b, outputs the alternating current through the terminal t3 to the third traction motor 16C, and outputs the alternating current through the terminal t4 to the fourth traction motor 16D, and the four traction motors 16 output rotation speed and torque under the action of the alternating current, and drive the whole machine to travel through the speed reducer 15.

Another electric energy transmission mode comprises the following steps: since the dc voltage supplied from the generator controller 4C to the traction motor controller 4D is generally high, the dc voltage may be directly output to the traction motor controller 4D and kept on at all times without passing through the VCU in a state where the generator 6 is operating. That is, as long as the generator 6 is in a power generation state, the generated electric energy can be directly transmitted to the traction motor controller 4D, and the VCU outputs only control signals to the generator controller 4C and the traction motor controller 4D.

After the driver steps on the electronic accelerator pedal 1, the VCU (central controller 4A) simultaneously sends signals to the generator controller 4C and the traction motor controller 4D according to an increase (decrease) signal of the angle of the electronic accelerator pedal 1, and requests the generator controller 4C to output power, and the power is increased (decreased); while traction motor controller 4D is required to output power to traction motors 16, and the power is increased (decreased). Meanwhile, after the conversion is carried out through the generator controller 4C, the conversion is carried out through inversion of the VCU central controller 4A and the traction motor controller 4D to alternating current, electric energy is output to a traction motor 16 of the driving assembly, and the traction motor 16 drives the whole machine to walk through a speed reducer 15.

In short, when the whole machine travels, the control signal is transmitted to the traction motor 16 according to the following path: an angle signal of the electronic accelerator pedal 1 is transmitted to a VCU (central controller 4A), the VCU (central controller 4A) simultaneously outputs signals to a generator controller 4C and a traction motor controller 4D, the traction motor controller 4D drives a driving assembly through a traction motor 16, and the driving assembly drives the whole machine to walk (move forwards or backwards).

In conjunction with each of the terminals described above, the signal transfer process is specifically: an angle signal of the electronic accelerator pedal 1 is input to the VCU through an output terminal and a u6 terminal of the VCU, the VCU outputs an electric power signal corresponding to the pedal angle to the generator controller 4C through an r0 terminal and an f1 terminal according to the pedal angle, and the generator controller 4C outputs the corresponding electric power to the VCU through an f2 terminal and a u9 terminal according to an instruction of the VCU. The VCU outputs electric energy corresponding to the angle of the electronic accelerator pedal 1 to the traction motor controller 4D through the r1 terminal and the t0 terminal, and the electric energy is transmitted to the traction motor 16 through the traction motor controller 4D, and the traction motor 16 outputs rotating speed and torque according to the angle of the electronic accelerator pedal 1 to drive the speed reducer to walk.

The VCU automatically detects the output power, the torque and the rotating speed of the engine 3 in real time through a u7 terminal, detects the angle signal of the electronic accelerator pedal 1 through a u6 terminal, and detects the rotating speed, the torque and other parameters of the four traction motors 16 through a u1 terminal, a u2 terminal, a u3 terminal and a u4 terminal.

2. When the driver does not lift the movable arm but carries out heavy-load walking transportation: at this time, the hydraulic controller 9 does not send a signal to the CAN7, the VCU (central controller 4A) does not detect the signal of the hydraulic controller 9 through the CAN7, and simultaneously detects that the power of the engine 3 completely meets the load requirement, that is, the power is much smaller than the rated power, a power generation signal is sent to the energy storage device 2 and the ISG motor 5, and the engine 3 drives the ISG motor 5 to charge the energy storage device 2. That is, the engine 3 drives the ISG motor 5 to generate power, the ISG motor 5 converts the alternating current into the direct current through the ISG controller 4B, and sends the direct current to the energy storage device controller 4E through the VCU (central controller 4A), and the energy storage device controller 4E inputs the direct current into the energy storage device 2 to store the direct current.

3. When the driver only controls the handle 11 to tilt backward for a certain angle, and the electronic accelerator pedal 1 has no input signal, the boom is lifted by the handle 11: i.e. the hydraulic power consumption is performed alone, the VCU (central controller 4A) automatically detects the power value of the engine 3 and compares it with the rated power, and the power of the engine 3 fully meets the load requirement, i.e. the power is much smaller than the rated power. The lifting time can be shortened by increasing the backward inclined angle of the handle 11. The VCU (central controller 4A) does not detect the input signal of the traveling, and does not output a signal instruction to the traction motor controller 4D, that is, the voltage generated by the generator 6 does not form a closed loop, so that the generator 6 continuously generates ac power under the driving of the engine 3, and is rectified by the generator controller 4C and output to the traction motor controller 4D through the VCU, and the traction motor controller 4D receives dc power, and does not receive an instruction of the VCU, so that the conversion of inverting the dc power to ac power or output electric power to the traction motor 16 is not performed, and the traction motor 16 does not receive ac power from the traction motor controller 4D, and maintains 0 rotation speed or gradually decelerates and stops depending on the inertia of the whole machine.

The second type of situation is: the heavy load of the whole machine is carried out by the combined working condition of lifting and walking.

When the whole machine is in heavy load to carry out combined working condition operation of lifting and walking, namely the angle of the electronic accelerator pedal 1 reaches or approaches to the maximum, and the lifting signal angle of the handle 11 reaches or approaches to the maximum. At this point, the power of the engine 3 is at or near maximum to meet the load power demand. So-called heavy loads include: above 80% rated load, full load and overload. The rated power of the engine 3 means: maximum value of the external output power of the engine 3 or a calibration power.

When the whole machine is lifted, the control signal is transmitted to the hydraulic pump 10 according to the following path: angle signal of handle 11 → hydraulic controller 9 → hydraulic pump 10, multi-way valve 12. The hydraulic pump 10 and the multi-way valve 12 are simultaneously opened to supply oil to the lift cylinder 13.

The method specifically comprises the following steps: the handle 11 is inclined rightward (as shown in fig. 1), an angle signal of the handle 11 is input to the hydraulic controller 9 through the output terminal h0, the hydraulic controller 9 outputs a corresponding displacement signal to the hydraulic pump 10 through the output terminal h1 according to the angle signal of the handle, outputs a corresponding spool displacement signal to the multi-way valve 12 through the output terminal h2, and transmits a hydraulic power output signal to the CAN7 through the output terminal h3 and the n0 terminal of the CAN 7.

The hydraulic pump 10 opens corresponding displacement according to the instruction of the hydraulic controller 9, the multi-way valve 12 realizes corresponding displacement of a valve core according to the instruction of the hydraulic controller 9, hydraulic oil is input to the large cavities of the two lifting cylinders 13 through the hydraulic pump 10 and ports d0 and d2 of the multi-way valve 12, and the small cavities of the two lifting cylinders 13 return to a tank through ports d1 and d3 of the multi-way valve 12, so that the lifting action of the oil cylinders is realized.

Specifically, when it is detected that the power of the engine 3 is close to or equal to the rated power, and the rotation speed (or power) of the traction motor 16 is not matched with the angle corresponding to the electronic accelerator pedal 1 (the rotation speed is relatively small or the power is relatively small), the VCU (central controller 4A) switches the signal that the ISG motor 5 charges the energy storage device 2 to the signal that the energy storage device 2 supplies power to the ISG, that is, sends a power output signal to the energy storage device controller 4E and the ISG controller 4B, the energy storage device controller 4E controls the energy storage device 2 and inputs the required power to the ISG controller 4B through the VCU, the ISG controller 4B drives the ISG motor 5 to switch the operating mode, and the ISG motor 5 is switched from the generator operating mode to the motor operating mode, that is, from the power generation state to the driving state. The ISG motor 5, together with the engine 3, then outputs mechanical power to the generator 6 and transfer case 8 having a power greater than the power rating of the engine 3.

In combination with the connection relationship of each terminal introduced above, the specific signal transmission process is as follows: the VCU outputs a power request signal to the energy storage device controller 4E through the r2 terminal and the E0 terminal, the energy storage device controller 4E sends an electric power output signal to the energy storage device 2 through the E3 terminal, the energy storage device 2 outputs a dc signal to the energy storage device controller 4E through the E1 terminal, the energy storage device controller 4E outputs a dc signal to the ISG controller 4B through the E2 terminal, the u5 terminal, the r4 terminal, and the g1 terminal of the VCU, the ISG controller 4B converts the dc signal into an ac signal through an inverter, and outputs an ac signal to the ISG motor 5 through the g3 terminal, at this time, the ISG motor 5 is converted into a motor, and outputs mechanical power to the generator 6 and the transfer case 8 together with the engine 3.

When the combined working condition works, the hybrid power is adopted to output power together: the VCU (central controller 4A) automatically detects the output power, torque and rotational speed of the engine 3, when it is detected that the power of the engine 3 is close to or equal to the rated power, the VCU (central controller 4A) sends power output signals to the energy storage device controller 4E and the ISG controller 4B, the energy storage device controller 4E controls the energy storage device 2 and inputs the direct current of the required power to the ISG controller 4B through the VCU (central controller 4A), the ISG controller 4B inverts the direct current into the alternating current required by the ISG motor 5, and outputs electric power to the ISG motor 5, the ISG motor 5 converts electric power output from the ISG controller 4B into mechanical power of the rotor, and together with the engine 3 outputs mechanical power to the generator 6 and transfer case 8 having a power rating greater than that of the engine 3. Here, the ISG motor 5 provides an additional power increment to the load through the energy storage device 2, ensuring that: the power of the engine is less than or equal to 95 percent of rated power and less than or equal to 3 percent of rated power, thereby meeting the high-efficiency operation of a hydraulic system and a driving assembly.

By adopting the control mode, the following advantages are achieved: on one hand: the power of the generator 6 is increased, the generator controller 4C converts alternating current into direct current, the generator controller 4C inputs electric energy to the traction motor controller 4D through a VCU (central control unit 4A), the traction motor controller 4D converts the direct current into alternating current required by the traction motor 16 through an inverter thereof, and outputs corresponding torque and rotation speed to the traction motor 16, and the traction motor 16 drives tires through a speed reducer 15, so that the whole vehicle runs at a corresponding speed. On the other hand: the power of the transfer case 8 is increased to a certain extent and drives the hydraulic pump 10, and the hydraulic oil pushes the oil cylinder to lift more quickly. Thereby meeting the combined operation requirement of heavy-load lifting and walking of the whole machine.

The technical scheme provided by the embodiment of the invention has the following advantages: 1. the cost is low. The whole power output control system can reduce the power and torque requirements of the engine 3, and the engine 3 with large power needs to be selected originally, so that the size is large, the discharge capacity is large, and the matched accessories have high cost, high oil consumption and large noise; the existing ISG motor 5 carries out power output and storage, so that the power of the existing engine 3 is comprehensively reduced, the oil consumption is reduced, the noise is reduced, the cost for purchasing the whole engine and the comprehensive use cost of the whole engine are reduced, and the market competitiveness is high.

2. The working efficiency is higher. When the power output control system works in a heavy load combined mode, the engine 3 and the ISG motor 5 output power to the load together, so that the lifting speed of the moving arm is increased, the walking speed of the whole machine is increased, the working time of each working cycle is correspondingly reduced, and the working efficiency of the whole operation is improved.

3. The flexibility of the whole machine is better, and the adaptability is wider. By adopting the complete machine of the power output control system, the ISG can not only output power to the load when necessary, but also charge the energy storage device 2, can perform efficient cooperative operation when needed, and can also perform charging energy saving when not needed, thereby having better adaptability and flexibility.

4. The supply is easy to realize. The manufacturing technology of the ISG motor 5, the controller 4, the lifting cylinder 13 and other related parts is mature, the processing is convenient, and the matching maturity of suppliers is high.

5. The oil consumption is lower: the working efficiency of the traditional complete machine is less than 70 percent, and because of adopting the scheme of a torque converter, a gearbox and a drive axle, 30 percent of fuel oil of a transmission system basically does not work, but heat is dissipated; the invention adopts an independent electric driving scheme, and omits large-mass transmission parts such as a torque converter, a gearbox, a drive axle and the like, so that the transmission system has smaller mass, the system has smaller heat generation, and the fuel consumption can be reduced by more than 10%.

Referring to fig. 3a to 4, other embodiments of the present invention further provide a loader control method, which can be implemented by the loader control system described above, and the steps of the method are described in detail below.

Step S100 is to determine the relationship between the rated power of the engine 3 and the power required by the current load.

Step S200, if the power required by the load is larger than or equal to the rated power of the engine 3, the ISG motor 5 is switched to a motor working mode, and the ISG motor 5 and the engine 3 drive the hydraulic pump 10 and the traction motor 16 to act together.

In some embodiments, the loader control method further comprises the steps of:

and step S300, if the power required by the load is less than the rated power of the engine 3, switching the ISG motor 5 to a generator working mode. The engine 3 drives the hydraulic pump 10, the ISG motor 5, and the traction motor 16. The electric energy generated by the ISG motor 5 is output to the energy storage device 2 for storage. The traction motor 16 acts to effect the travel of the loader. The ISG motor 5 generates power.

Referring to fig. 3a, fig. 3a illustrates that the ISG motor 5 and the engine 3 output power together, and the ISG motor 5 takes out electric energy from the energy storage device 2. Specifically, the energy storage device 2 transmits electric energy to the energy storage device controller 4E, the energy storage device controller 4E outputs direct current to the VCU, the VCU transmits the electric energy to the ISG controller 4B, and the ISG controller 4B inverts the direct current into alternating current and then provides the alternating current for the ISG motor 5. The ISG motor 5 and the engine 3 output power together.

Referring to fig. 3b, fig. 3b illustrates that the ISG motor 5 reversely charges the energy storage device 2 to store electric energy. Specifically, the ISG motor 5 transmits ac power to the ISG controller 4B, the ISG controller 4B converts the ac power into dc power and transmits the dc power to the VCU, the VCU transmits the electric power to the energy storage device controller 4E, and the energy storage device controller 4E transmits the dc power to the energy storage device 2 for storage.

Referring to fig. 3c, fig. 3c illustrates the process of the generator 6 outputting power to the traction motor 16. Specifically, ac power input by the generator 6 is transmitted to the generator controller 4C, the generator controller 4C converts the ac power to dc power and transmits it to the VCU, and then the VCU transmits the dc power to the traction motor controller 4D, and the traction motor controller 4D inverts the current into ac power and transmits it to the traction motor 16.

In the description of the present invention, it is to be understood that the terms "central", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate orientations or positional relationships based on those shown in the drawings, and are used only for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be considered as limiting the scope of the present invention.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: it is to be understood that modifications may be made to the technical solutions described in the foregoing embodiments, or equivalents may be substituted for some of the technical features thereof, but such modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A loader control system, comprising:

an engine (3) configured to provide rotational kinetic energy;

the ISG motor (5) is in driving connection with the engine (3); the ISG motor (5) comprises a generator working mode and a motor working mode;

the generator (6) is in driving connection with the ISG motor (5);

the controller (4) is electrically connected with the generator (6) and the ISG motor (5); the controller (4) is in communication connection with the engine (3); the controller (4) is configured to switch an operation mode of the ISG motor (5);

the energy storage device (2) is electrically connected with the controller (4); wherein the energy storage device (2) is charged via the ISG motor (5) when the ISG motor (5) is in a generator mode of operation; when the ISG motor (5) is in a motor working mode, the energy storage device (2) provides electric energy to the ISG motor (5) through the controller (4);

a lifting system comprising a hydraulic pump (10) and a lifting cylinder (13); the hydraulic pump (10) is connected with the lifting cylinder (13) through a hydraulic oil circuit; the engine (3) is in driving connection with the hydraulic pump (10) through the ISG motor (5) and the generator (6); and

the driving assembly comprises a traction motor (16) and a speed reducer (15), and the traction motor and the speed reducer are in driving connection; the generator (6) is electrically connected with the traction motor (16) through the controller (4) to transmit electric energy to the traction motor (16).

2. The loader control system according to claim 1, wherein the controller (4) comprises:

a central controller (4A) which is connected with the engine (3) in a communication way to control the output power of the engine (3);

the ISG controller (4B) is in communication connection with the central controller (4A), and the ISG controller (4B) is also electrically connected with the ISG motor (5); the ISG controller (4B) is configured to switch an operation mode of the ISG motor (5) between a generator operation mode and a motor operation mode;

a generator controller (4C) in communication with the central controller (4A), the generator controller (4C) further electrically connected with the generator (6);

an energy storage device controller (4E) in communication with the central controller (4A), the energy storage device controller (4E) further electrically connected with the energy storage device (2); and

a traction motor controller (4D) in communication with the central controller (4A), the traction motor controller (4D) further being electrically connected with the traction motor (16).

3. The loader control system of claim 2, wherein the lift system further comprises:

a handle (11) configured to output a lifting signal to control the lifting cylinder (13) to act;

a multi-way valve (12) provided in an oil passage of the hydraulic pump (10);

the hydraulic controller (9) is in communication connection with the handle (11) so as to adjust a working angle signal of the handle (11); the hydraulic controller (9) is also in communication connection with the multi-way valve (12) to control the displacement of a valve core of the multi-way valve (12); and

the hydraulic controller (9) is in communication connection with the central controller (4A) through the CAN (7).

4. The loader control system of claim 2, further comprising:

an electronic accelerator pedal (1) electrically connected to the central controller (4A), the controller (4) being configured to control the output power of the traction motor (16) according to an angle signal of the electronic accelerator pedal (1).

5. The loader control system according to claim 2, characterized in that the traction motors (16) comprise four, each traction motor (16) being individually assigned one of the traction motor controllers (4D).

6. The loader control system according to claim 2, wherein the central controller (4A) and the ISG controller (4B) are configured to perform the following operations:

the central controller (4A) judges the relationship between the rated power of the engine (3) and the power required by the current load;

if the power required by the load is less than the rated power of the engine (3), the central controller (4A) sends a signal for switching the ISG motor (5) operation mode to a generator operation mode to the ISG controller (4B), and the ISG controller (4B) switches the ISG motor (5) operation mode to the generator operation mode; if the power required by the load is greater than or equal to the rated power of the engine (3), the central controller (4A) sends a signal for switching the ISG motor (5) operation mode to the motor operation mode to the ISG controller (4B), and the ISG controller (4B) switches the ISG motor (5) operation mode to the motor operation mode.

7. The loader control system according to claim 6, characterized in that when the ISG motor (5) is in generator mode:

the power transmission path is: the engine (3) drives the ISG motor (5) and the generator (6) to rotate;

the power generation path is as follows: the engine (3) drives the ISG motor (5) to rotate, and the ISG motor (5) transmits the generated electric energy to the energy storage device (2) after being converted by the controller (4).

8. The loader control system according to claim 6, characterized in that when the ISG motor (5) is in generator mode:

the transmission process of the walking kinetic energy is as follows: the generator (6) rotates to generate electricity, and the electric energy sent by the generator (6) is transmitted to the traction motor (16) through the controller (4).

9. The loader control system according to claim 6, characterized in that when the ISG motor (5) is in motor operation mode:

the power transmission path is: the energy storage device (2) drives the ISG motor (5) to rotate, and the engine (3) and the ISG motor (5) jointly drive the hydraulic pump (10) to rotate;

the power consumption path is as follows: the energy storage device (2) transmits electric energy to the ISG motor (5) through the controller (4) so as to drive the ISG motor (5) to rotate.

10. The loader control system according to claim 9, wherein when the ISG motor (5) is in motor operation mode:

the transmission process of the walking kinetic energy is as follows: the generator (6) rotates to generate electricity, and the electric energy sent by the generator (6) is transmitted to the speed reducer (15) through the controller (4).

11. A loader control system according to claim 1 where the power required by the load is less than the rated power of the engine (3) in each of the following situations: the loader normally runs, the loader is lifted independently, and the loader performs combined working condition operation that the loader travels while lifting, and both the loader travels and the loader lifts do not reach a limit state.

12. The loader control system according to claim 1, characterized in that the power required by the load is greater than or equal to the rated power of the engine (3) in each of the following situations: the loader performs combined working condition operation of lifting while walking, and at least one of walking and lifting reaches a limit state.

13. The loader control system of claim 1, further comprising:

a transfer case (8) disposed between the generator (6) and the hydraulic pump (10), the transfer case (8) being configured to receive the rotational power output from the engine (3) and the ISG motor (5) in a motor operation mode and to transmit to the hydraulic pump (10).

14. A loader comprising a loader control system according to any one of claims 1 to 13.

15. A loader control method, characterized by comprising the steps of:

16. The loader control method according to claim 15, further comprising the step of: