A control method for an electric slewing system based on a hydraulic system

Abstract

This invention discloses a control method for an electric rotary system based on a hydraulic system. The method involves controlling the electric rotary system using a hydraulic system by adding a pressure sensor to the rotary oil circuit connected to the pilot valve to monitor pressure changes in the rotary oil circuit. The operating mode of the electric rotary system is determined by the pressure changes in the left and right rotary oil circuits. This invention provides a control method for an electric rotary system based on a hydraulic system. It adds an electric rotary mechanism to the existing hydraulic system to form an electric rotary system, and controls the electric rotary system. The control method is designed based on the pressure changes in different rotary oil circuits of the pilot valve in the hydraulic system, providing switching conditions and control methods for three different modes: rotary mode, stationary mode, and fault mode. This ensures the safety of the electric rotary system and reduces the development cycle and workload.

Description

Technical Field

[0001] This invention relates to a control method for an electric rotary system based on a hydraulic system, belonging to the field of engineering machinery technology. Background Technology

[0002] Excavators are common construction machinery with slewing systems. Existing excavators are equipped with hydraulic systems, which generally include hydraulic pilot mechanical handles, pilot valves, and hydraulic circuits. By operating the hydraulic pilot mechanical handles, the pilot valves are controlled to open and close. The hydraulic circuits are connected to the hydraulic slewing motors. By changing the hydraulic oil pressure in the hydraulic circuits through the pilot valves, the hydraulic slewing motors are rotated, thereby driving the slewing system to rotate.

[0003] However, with the rapid development of electrification in construction machinery, the performance of existing hydraulic rotary motors is gradually being surpassed by rotary motors. Therefore, it is necessary to electrify a large number of construction machines with rotary systems. However, in order to avoid wasting resources of components such as hydraulic systems and to avoid excessive duplication of design, how to use the existing hydraulic system to control the operation of the rotary motor after replacing the original hydraulic rotary motor with a rotary motor has become a technical problem that urgently needs to be solved by those skilled in the art.

[0004] In existing slewing system control technologies, the following solutions have been proposed for controlling slewing systems:

[0005] The first prior art provides an electric slewing system for controlling the slewing device of engineering machinery, but it completely replaces the original hydraulic system.

[0006] The second prior art provides an electric rotary control device, but this control device controls the output magnitude and output direction of the rotary motor based on the return torque becoming zero.

[0007] The third existing technology provides a composite drive system for an electric excavator. During the start-up process of the slewing motor, the torque and torque control of the slewing motor are performed separately in different operating modes by setting multiple speeds. However, it does not describe the static or braking control of the slewing system.

[0008] The fourth prior art provides a slewing control system and method for construction machinery using an electric motor, which calculates a reference slewing torque through a slewing operation signal and calculates the gain torque by the difference between the reference torque and the actual slewing torque of the currently fed-out electric motor, without considering control when there is no slewing operation signal or when the slewing operation signal is faulty.

[0009] To avoid the above situation, the present invention makes the following improvements to the control method of the electric rotary system. Summary of the Invention

[0010] Objective: In order to overcome the shortcomings of the existing technology, the present invention provides a control method for an electric rotary system based on a hydraulic system.

[0011] Technical solution: To solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0012] A control method for an electric rotary system based on a hydraulic system includes: rotary mode, stationary mode, fault mode, and mode switching control.

[0013] The slewing mode includes a left slewing control method and a right slewing control method.

[0014] The left turn control method includes the following steps:

[0015] When the pressure signal of the left turn pilot hydraulic circuit is greater than the set effective threshold for left turn and the pressure signal of the right turn pilot hydraulic circuit is less than the set effective threshold for right turn, the vehicle controller determines that the left turn control command is valid and executes the left turn control. Otherwise, the vehicle controller determines that the left turn control command is invalid and does not execute any action.

[0016] The vehicle controller calculates the torque value of the rotary motor based on the current pressure signal of the left rotary pilot oil circuit and the difference between the current and previous pressure signals of the left rotary pilot oil circuit.

[0017] The right turn control method includes the following steps:

[0018] When the pressure signal in the left turn pilot oil circuit is less than the set effective left turn threshold and the pressure signal in the right turn pilot oil circuit is greater than the set effective right turn threshold, the vehicle controller determines that the right turn control command is valid and executes the right turn control. Otherwise, the vehicle controller determines that the right turn control command is invalid and does not perform any action.

[0019] The vehicle controller calculates the torque value of the rotary motor based on the current pressure signal of the right rotary pilot oil circuit and the difference between the current and previous pressure signals of the right rotary pilot oil circuit.

[0020] The static mode control method includes the following steps:

[0021] When the pressure signal of the left turn pilot hydraulic circuit is less than the set effective threshold for left turn and the pressure signal of the right turn pilot hydraulic circuit is less than the set effective threshold for right turn, the vehicle controller determines that the stationary mode control command is valid and executes the stationary mode control. Otherwise, the vehicle controller determines that the stationary mode control command is invalid and does not perform any action.

[0022] Set a static state holding time threshold. If the duration of the static mode control command is less than the static state holding time threshold, the rotary motor is in a 0 torque state. If the duration of the static mode control command is greater than the static state holding time threshold, the parking system starts working and puts the rotary motor in a stopped state.

[0023] If the static mode control command is released, it is determined whether the actual torque of the rotary motor is greater than the set rotary torque threshold. If it is greater than the rotary torque threshold, the rotary motor starts; if the actual torque of the rotary motor is less than the set rotary torque threshold, the electric rotary system remains in static mode.

[0024] The fault mode control method includes the following steps:

[0025] When the pressure signal of the left slewing pilot oil circuit is greater than the set effective threshold for left slewing and the pressure signal of the right slewing pilot oil circuit is greater than the set effective threshold for right slewing, or when the vehicle is in a serious fault state, the vehicle controller determines that the electric slewing system is in a fault state, controls the slewing motor to be stationary and starts the electric slewing parking function.

[0026] As a preferred embodiment, the mode switching control involves setting switching conditions between slewing mode, stationary mode, and fault mode. When the switching conditions are met, the mode is switched. The switching conditions are as follows:

[0027] Conditions for switching to left turn from stationary mode:

[0028] e) The torque command of the rotary motor is greater than the set starting threshold.

[0029] f) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn.

[0030] g) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn.

[0031] h) The vehicle has no serious malfunctions.

[0032] The above conditions are logically related by "AND".

[0033] Conditions for switching to right turn from stationary mode:

[0034] e) The torque command of the rotary motor is greater than the set starting threshold.

[0035] f) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn.

[0036] g) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn.

[0037] h) The vehicle has no serious malfunctions.

[0038] The above conditions are logically related by "AND".

[0039] Conditions for switching from static mode to fault mode:

[0040] d) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn.

[0041] e) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn.

[0042] f) The vehicle has a serious malfunction.

[0043] a) and b) are logically ANDed, while c) is logically ORed.

[0044] Conditions for switching from left turn to stationary mode:

[0045] d) The feedback speed signal of the rotary motor is less than the set feedback threshold.

[0046] e) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn.

[0047] f) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn.

[0048] The above conditions are logically related by "AND".

[0049] The conditions for switching to stationary mode when turning right are as follows:

[0050] d) The feedback speed signal of the rotary motor is less than the set feedback threshold.

[0051] e) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn.

[0052] f) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn.

[0053] The above conditions are related by a logical AND statement.

[0054] Conditions for switching from left turn to right turn:

[0055] d) The feedback speed signal of the rotary motor is less than the set feedback threshold.

[0056] e) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn.

[0057] f) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn.

[0058] The above conditions are related by a logical AND statement.

[0059] Conditions for switching from right turn to left turn:

[0060] d) The feedback speed signal of the rotary motor is less than the set feedback threshold.

[0061] e) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn.

[0062] f) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn.

[0063] The above conditions are logically related by "AND".

[0064] Left turn fault mode switching conditions:

[0065] c) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn.

[0066] d) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn.

[0067] The above conditions are logically related by "AND".

[0068] The switching conditions for the right turn fault mode are as follows:

[0069] c) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn.

[0070] d) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn.

[0071] The above conditions are logically related by "AND".

[0072] Fault mode switching to static mode switching conditions:

[0073] d) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn.

[0074] e) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn.

[0075] f) The vehicle has no serious malfunctions.

[0076] The above conditions are logically related by "AND".

[0077] As a preferred option, when switching between left turn mode and right turn mode due to a fault, you must first enter the stationary mode.

[0078] As a preferred embodiment, the method for obtaining the torque value of the rotary motor includes the following steps:

[0079] The pressure sensor signal value k corresponding to the opening degree of the rotary control handle is collected in real time.

[0080] Calculate the rate of change h of the pressure sensor signal. h = Δk / Δt, where Δk represents the pressure difference between the current moment and the previous moment, and Δt represents the time difference between the current moment and the previous moment.

[0081] The target torque data value n of the rotary motor is found from the curve f based on the pressure sensor signal value k.

[0082] Based on the rate of change h of the pressure sensor signal value, the basic value n1 of the target torque of the rotary motor is calculated, where n1 = h * n.

[0083] The additional torque value n2 is obtained by using a fuzzy control algorithm based on the difference between the actual rotation speed and the target rotation speed of the slewing platform.

[0084] Based on the base value n1 and the additional torque value n2, the torque value N of the rotary motor is calculated, N = n1 + n2.

[0085] As a preferred embodiment, the pressure sensor signal value k, k∈[-1 1], is linearly proportionally converted according to the physical position of the rotary operating handle.

[0086] As a preferred option, when k=0, the slewing operating handle is in the neutral position, the pressure sensor value is 0, which means that the electric slewing system does not perform any movement.

[0087] Define the movement of the rotary operating handle from the center position to a specified direction as performing a leftward angle operation, where k > 0, and k = 1 when the handle reaches the limit position.

[0088] The movement of the rotary operating handle from the center position to the opposite direction represents a rightward rotary operation, where k < 0, and k = -1 when the handle reaches the limit position.

[0089] As a preferred embodiment, the method for obtaining the additional torque value n2 includes the following steps:

[0090] Based on the current rotational speed of the rotary motor, the actual rotational speed v1 of the rotary platform is calculated by converting the transmission ratio of the reducer.

[0091] The target leftward rotation speed of the rotary platform is obtained by measuring the signal value from the pressure sensor, and is defined as v2 = k * v max v max This is the design value for the maximum speed of the slewing platform.

[0092] The input variables of the fuzzy control algorithm are the difference e between v1 and v2, and the rate of change e′ of the difference. According to the fuzzy control rules, the output variable is the additional torque value n2.

[0093] As a preferred approach, the method for obtaining fuzzy control rules is as follows:

[0094] Define the fuzzy subset of the difference e as {-0.2,-0.1,0,0.1,0.2}, and the corresponding linguistic variables are {vs,s,z,b,vb}.

[0095] The fuzzy subset of the rate of change e′ is defined as {-2,-1,0,1,2}, and the corresponding linguistic variables are {vs,s,z,b,vb}.

[0096] The fuzzy subset of the additional torque value n2 is defined as {-100,-50,0,50,100}, and the corresponding linguistic variables are {vs,s,z,b,vb}. Fuzzy control rules are established, as detailed in Table 1.

[0097] Table 1

[0098]

[0099]

[0100] Beneficial effects: The present invention provides a control method for an electric rotary system based on a hydraulic system. The electric rotary system is controlled based on a hydraulic system. A pressure sensor is installed on the rotary oil circuit connected to the pilot valve to monitor the pressure changes in the rotary oil circuit. The working mode of the electric rotary system is determined by the pressure changes in the left and right rotary oil circuits.

[0101] This invention categorizes the operating modes of the electric slewing system into slewing mode, stationary mode, fault mode, and mode switching, and establishes control methods for electric slewing under different modes, as well as switching conditions between modes. The electric slewing system is modified while maintaining the overall excavator frame, reducing the development cycle and workload of the electric slewing system. Attached Figure Description

[0102] Figure 1 This is a schematic diagram of the electric rotary system.

[0103] Figure 2 This is a flowchart of the left-hand slewing control method for an electric slewing system.

[0104] Figure 3 This is a flowchart of the right-hand slewing control method for an electric slewing system.

[0105] Figure 4 This is a flowchart of the static mode control method for an electric rotary system.

[0106] Figure 5 This is a control diagram for the mode switching of the electric rotary system. Detailed Implementation

[0107] The present invention will be further described below with reference to specific embodiments.

[0108] like Figure 1 As shown, an electric slewing system based on a hydraulic system includes: an electric slewing mechanism, a pressure sensor, a vehicle controller, a slewing operation device, and a hydraulic system.

[0109] The electric slewing mechanism includes: a slewing motor, a slewing motor controller, a reducer, and a parking system. The slewing motor drives the slewing gear through the reducer. The slewing motor controller controls the slewing motor and is connected to the vehicle controller. The reducer is connected to the slewing motor and serves to reduce speed and increase torque. The parking system locks the slewing motor when the slewing system is stationary or malfunctions, providing safety protection.

[0110] The pressure sensors include a left-turn pressure sensor and a right-turn pressure sensor. The left-turn pressure sensor is used to sense the pressure change in the left-turn pilot oil circuit, and the right-turn pressure sensor is used to sense the pressure change in the right-turn pilot oil circuit. The left-turn pressure sensor and the right-turn pressure sensor are connected to the vehicle controller and transmit the collected pressure changes to the vehicle controller.

[0111] The hydraulic system includes: a pilot valve, a hydraulic pump, a drive motor, and a drive motor controller. The drive motor drives the hydraulic pump, which provides the required pressure and flow to the rotary system. The pilot valve is connected to the left rotary pilot oil circuit and the right rotary pilot oil circuit respectively, and is used to control the pressure and flow changes of the left rotary pilot oil circuit and the right rotary pilot oil circuit of the rotary system. The drive motor controller is connected to the drive motor and is used to control the drive motor.

[0112] The vehicle controller is connected to the rotary motor controller to control the start and stop of the rotary motor; it is also connected to the drive motor controller to control the start and stop of the drive motor.

[0113] The rotary operating device includes a rotary operating handle, which is a hydraulic handle connected to the pilot valve and used to control the opening and closing of the pilot valve.

[0114] A control method for an electric rotary system based on a hydraulic system mainly includes rotary mode, stationary mode, fault mode and mode switching control.

[0115] Slewing mode control method:

[0116] like Figure 2 As shown, the left turn control method is as follows:

[0117] When the pressure signal of the left turn pilot hydraulic circuit is greater than the set effective threshold for left turn and the pressure signal of the right turn pilot hydraulic circuit is less than the set effective threshold for right turn, the vehicle controller determines that the left turn control command is valid and executes the left turn control. Otherwise, the vehicle controller determines that the left turn control command is invalid and does not execute any action.

[0118] The vehicle controller calculates the torque value of the rotary motor based on the current pressure signal of the left rotary pilot oil circuit and the difference between the current and previous pressure signals of the left rotary pilot oil circuit.

[0119] like Figure 3 As shown, the right turn control method is as follows:

[0120] When the pressure signal in the left turn pilot oil circuit is less than the set effective left turn threshold and the pressure signal in the right turn pilot oil circuit is greater than the set effective right turn threshold, the vehicle controller determines that the right turn control command is valid and executes the right turn control. Otherwise, the vehicle controller determines that the right turn control command is invalid and does not perform any action.

[0121] The vehicle controller calculates the torque value of the rotary motor based on the current pressure signal of the right rotary pilot oil circuit and the difference between the current and previous pressure signals of the right rotary pilot oil circuit.

[0122] Static mode control:

[0123] like Figure 4 As shown, when the pressure signal of the left turn pilot oil circuit is less than the set effective threshold for left turn and the pressure signal of the right turn pilot oil circuit is less than the set effective threshold for right turn, the vehicle controller determines that the stationary mode control command is valid and executes the stationary mode control. Otherwise, the vehicle controller determines that the stationary mode control command is invalid and does not perform any action.

[0124] Set a static state holding time threshold. If the duration of the static mode control command is less than the static state holding time threshold, the rotary motor is in a 0 torque state. If the duration of the static mode control command is greater than the static state holding time threshold, the parking system starts working and puts the rotary motor in a stopped state.

[0125] If the static mode control command is released, it is determined whether the actual torque of the rotary motor is greater than the set rotary torque threshold. If it is greater than the rotary torque threshold, the rotary motor starts; if the actual torque of the rotary motor is less than the set rotary torque threshold, the electric rotary system remains in static mode.

[0126] Fault Mode Control:

[0127] When the pressure signal of the left slewing pilot oil circuit is greater than the set effective threshold for left slewing and the pressure signal of the right slewing pilot oil circuit is greater than the set effective threshold for right slewing, or when the vehicle is in a serious fault state, the vehicle controller determines that the electric slewing system is in a fault state, controls the slewing motor to be stationary and starts the electric slewing parking function.

[0128] Mode switching control: Mode switching control mainly involves setting the switching conditions between slewing mode, stationary mode and fault mode. Slewing mode includes switching between left slewing control and right slewing control.

[0129] Example:

[0130] The method of this invention allows for the addition of an electric rotary mechanism to an existing hydraulic system, forming an electric rotary system. The electric rotary system is then controlled by designing a control method based on the pressure changes in different rotary oil circuits of the hydraulic system's pilot valve. This method includes switching conditions and control methods for three different modes: rotary mode, stationary mode, and fault mode, ensuring the safety of the electric rotary system.

[0131] The torque values ​​of the rotary motor in left and right rotary modes are calculated as follows:

[0132] Taking the left turn mode as an example:

[0133] The opening degree of the slewing control handle to the left is collected in real time, along with the left slewing pressure sensor signal value k and the pressure sensor signal change rate h = Δk / Δt, where Δk represents the pressure difference between the current moment and the previous moment, and Δt represents the time difference between the current moment and the previous moment.

[0134] The target torque data value n of the rotary motor is found from the curve f based on the pressure sensor signal value k.

[0135] Based on the rate of change h of the pressure sensor signal value, the basic value of the leftward target torque of the rotary motor is calculated as n1 = h * n.

[0136] Based on the difference between the actual leftward rotation speed of the slewing platform and the target leftward rotation speed, the additional torque value n2 is solved using a fuzzy control algorithm.

[0137] The final target torque value of the rotary motor is calculated to be N = n1 + n2.

[0138] Furthermore, the pressure sensor signal value k is defined as k∈[-1 1], and is linearly proportionally converted according to the physical position of the rotary operating handle.

[0139] When k=0, the slewing operating handle is in the neutral position, the pressure sensor value is 0, which means that the electric slewing system does not move at all.

[0140] Define the movement of the rotary operating handle from the center position to a specified direction as performing a leftward angle operation, where k > 0, and k = 1 when the handle reaches the limit position.

[0141] The movement of the rotary operating handle from the center position to the opposite direction represents a rightward rotary operation, where k < 0, and k = -1 when the handle reaches the limit position.

[0142] Furthermore, the method for solving the additional torque value n2 includes:

[0143] Based on the current rotational speed of the rotary motor, the actual rotational speed v1 of the rotary platform is calculated by converting the transmission ratio of the reducer.

[0144] The target leftward rotation speed of the rotary platform is obtained by measuring the signal value from the pressure sensor, and is defined as v2 = k * v max v max This is the design value for the maximum speed of the slewing platform.

[0145] The input variables of the fuzzy control algorithm are the difference e between v1 and v2, and the rate of change e′ of the difference. According to the fuzzy control rules, the output variable is the additional torque value n2.

[0146] Define the fuzzy subset of the difference e as {-0.2,-0.1,0,0.1,0.2}, and the corresponding linguistic variables are {vs,s,z,b,vb}.

[0147] The fuzzy subset of the rate of change e′ is defined as {-2,-1,0,1,2}, and the corresponding linguistic variables are {vs,s,z,b,vb}.

[0148] The fuzzy subset of the additional torque value n2 is defined as {-100,-50,0,50,100}, and the corresponding linguistic variables are {vs,s,z,b,vb}. Fuzzy control rules are established, as detailed in Table 1.

[0149] Table 1

[0150]

[0151]

[0152] Furthermore, the mode switching control method is as follows:

[0153] Conditions for switching from stationary mode to left turn:

[0154] i) The torque command of the rotary motor is greater than the set starting threshold;

[0155] j) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn;

[0156] k) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn;

[0157] l) The vehicle has no serious malfunctions;

[0158] The above conditions are related by a logical AND statement.

[0159] Conditions for switching from stationary mode to right turn:

[0160] i) The torque command of the rotary motor is greater than the set starting threshold;

[0161] j) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn;

[0162] k) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn;

[0163] l) The vehicle has no serious malfunctions;

[0164] The above conditions are related by a logical AND statement.

[0165] Conditions for switching between static and fault modes:

[0166] g) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn;

[0167] h) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn;

[0168] i) The vehicle has a serious malfunction;

[0169] a) and b) are logically ANDed, while c) is logically ORed. Left turn to stationary mode switching conditions:

[0170] g) The feedback speed signal from the rotary motor is less than the set feedback threshold;

[0171] h) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn;

[0172] i) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn;

[0173] The above conditions are related by a logical AND statement.

[0174] Right turn to stationary mode switching conditions:

[0175] g) The feedback speed signal from the rotary motor is less than the set feedback threshold;

[0176] h) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn;

[0177] i) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn;

[0178] The above conditions are related by a logical AND statement.

[0179] Left turn to right turn switching conditions:

[0180] g) The feedback speed signal from the rotary motor is less than the set feedback threshold;

[0181] h) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn;

[0182] i) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn;

[0183] The above conditions are related by a logical AND statement.

[0184] Right turn to left turn switching conditions:

[0185] g) The feedback speed signal from the rotary motor is less than the set feedback threshold;

[0186] h) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn;

[0187] i) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn;

[0188] The above conditions are related by a logical AND statement.

[0189] Left turn fault mode switching conditions:

[0190] e) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn;

[0191] f) The pressure signal of the right-hand rotation oil circuit is greater than the set effective threshold for right-hand rotation;

[0192] The above conditions are related by a logical AND statement.

[0193] Right turn fault mode switching conditions:

[0194] e) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn;

[0195] f) The pressure signal of the right-hand rotation oil circuit is greater than the set effective threshold for right-hand rotation;

[0196] The above conditions are related by a logical AND statement.

[0197] Fault mode switching and static mode switching conditions:

[0198] g) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn;

[0199] h) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn;

[0200] i) The vehicle has no serious malfunctions;

[0201] The above conditions are related by a logical AND statement.

[0202] Fault mode switching conditions for switching between left turn mode and right turn mode:

[0203] For the sake of overall vehicle safety, this invention sets that when switching between left turn mode and right turn mode in case of a fault, the vehicle must first enter a stationary mode, and then enter the left turn mode or right turn mode according to the switching conditions.

[0204] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control method for an electric rotary system based on a hydraulic system, comprising: The system features rotary mode, stationary mode, fault mode, and mode switching control, characterized by: The turning mode includes a left turn control method and a right turn control method; The left turn control method includes the following steps: When the pressure signal of the left turn pilot oil circuit is greater than the set effective threshold for left turn and the pressure signal of the right turn pilot oil circuit is less than the set effective threshold for right turn, the vehicle controller determines that the left turn control command is valid and executes the left turn control; otherwise, the vehicle controller determines that the left turn control command is invalid and does not execute any action. The vehicle controller calculates the torque value of the rotary motor based on the current pressure signal of the left rotary pilot oil circuit and the difference between the current and previous pressure signals of the left rotary pilot oil circuit. The right turn control method includes the following steps: When the pressure signal of the left turn pilot oil circuit is less than the set effective threshold for left turn and the pressure signal of the right turn pilot oil circuit is greater than the set effective threshold for right turn, the vehicle controller determines that the right turn control command is valid and executes the right turn control; otherwise, the vehicle controller determines that the right turn control command is invalid and does not execute any action. The vehicle controller calculates the torque value of the rotary motor based on the current pressure signal of the right rotary pilot oil circuit and the difference between the current and previous pressure signals of the right rotary pilot oil circuit. The static mode control method includes the following steps: When the pressure signal of the left turn pilot oil circuit is less than the set effective threshold for left turn and the pressure signal of the right turn pilot oil circuit is less than the set effective threshold for right turn, the vehicle controller determines that the stationary mode control command is valid and executes the stationary mode control; otherwise, the vehicle controller determines that the stationary mode control command is invalid and does not execute any action. Set a static state holding time threshold. If the duration of the static mode control command is less than the static state holding time threshold, the rotary motor is in a 0 torque state. If the duration of the static mode control command is greater than the static state holding time threshold, the parking system starts working and puts the rotary motor in a stopped state. If the static mode control command is released, it is determined whether the actual torque of the rotary motor is greater than the set rotary torque threshold. If it is greater than the rotary torque threshold, the rotary motor starts; if the actual torque of the rotary motor is less than the set rotary torque threshold, the electric rotary system remains in static mode. The fault mode control method includes the following steps: When the pressure signal of the left slewing pilot oil circuit is greater than the set effective threshold for left slewing and the pressure signal of the right slewing pilot oil circuit is greater than the set effective threshold for right slewing, or when the vehicle is in a serious fault state, the vehicle controller determines that the electric slewing system is in a fault state, controls the slewing motor to be stationary and starts the electric slewing parking function.

2. The control method for an electric rotary system based on a hydraulic system according to claim 1, characterized in that: The mode switching control is achieved by setting switching conditions between slewing mode, stationary mode, and fault mode. When the switching conditions are met, the mode is switched. The switching conditions are as follows: Conditions for switching to left turn from stationary mode: a) The torque command of the rotary motor is greater than the set starting threshold; b) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn; c) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn; d) The vehicle has no serious malfunctions; The above conditions are logically related by "AND". Conditions for switching to right turn from stationary mode: a) The torque command of the rotary motor is greater than the set starting threshold; b) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn; c) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn; d) The vehicle has no serious malfunctions; The above conditions are logically related by "AND". Conditions for switching from static mode to fault mode: a) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn; b) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn; c) The vehicle has a serious malfunction; a) and b) are logically ANDed, and c) is logically ORed; the switching condition for left turn to stationary mode is: a) The feedback speed signal from the rotary motor is less than the set feedback threshold; b) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn; c) The pressure signal of the right turn oil circuit is less than the set right turn effective threshold; the above conditions are logically ANDed. The conditions for switching to stationary mode when turning right are as follows: a) The feedback speed signal from the rotary motor is less than the set feedback threshold; b) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn; c) The pressure signal of the right turn oil circuit is less than the set right turn effective threshold; the above conditions are logically ANDed. Conditions for switching from left turn to right turn: a) The rotational motor's feedback speed signal is less than the set feedback threshold; b) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn; c) The pressure signal of the right turn oil circuit is greater than the set right turn effective threshold; the above conditions are logically ANDed. Conditions for switching from right turn to left turn: a) The rotational motor's feedback speed signal is less than the set feedback threshold; b) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn; c) The pressure signal of the right turn oil circuit is less than the set right turn effective threshold; the above conditions are logically ANDed. Left turn fault mode switching conditions: a) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn; b) The pressure signal of the right turn oil circuit is greater than the set right turn effective threshold; the above conditions are logically ANDed. The switching conditions for the right turn fault mode are as follows: a) The pressure signal of the left turn oil circuit is greater than the set effective threshold for left turn; b) The pressure signal of the right turn oil circuit is greater than the set effective threshold for right turn; The above conditions are logically related by "AND". Fault mode switching to static mode switching conditions: a) The pressure signal of the left turn oil circuit is less than the set effective threshold for left turn; b) The pressure signal of the right turn oil circuit is less than the set effective threshold for right turn; c) The vehicle has no serious malfunctions; The above conditions are logically related by "AND".

3. The control method for an electric rotary system based on a hydraulic system according to claim 2, characterized in that: When switching between left turn mode and right turn mode due to a fault, you must first enter stationary mode.

4. The control method for an electric rotary system based on a hydraulic system according to claim 1, characterized in that: The method for obtaining the torque value of a rotary motor includes the following steps: Real-time acquisition of the pressure sensor signal value k corresponding to the opening degree of the rotary control handle; Calculate the rate of change h of the pressure sensor signal; h = Δk / Δt, where Δk represents the pressure difference between the current moment and the previous moment, and Δt represents the time difference between the current moment and the previous moment; The target torque data value n of the rotary motor is found from the curve f based on the pressure sensor signal value k; Based on the rate of change h of the pressure sensor signal value, the basic value n1 of the target torque of the rotary motor can be calculated, where n1 = h * n; Based on the difference between the actual slewing speed and the target slewing speed of the slewing platform, the additional torque value n2 is solved by a fuzzy control algorithm. Based on the base value n1 and the additional torque value n2, the torque value N of the rotary motor is calculated. N = n1 + n2.

5. The control method for an electric rotary system based on a hydraulic system according to claim 4, characterized in that: The pressure sensor signal value k, k∈[-1, 1], is linearly proportionally converted according to the physical position of the rotary operating handle.

6. The control method for an electric rotary system based on a hydraulic system according to claim 5, characterized in that: When k=0, the slewing operating handle is in the neutral position, the pressure sensor value is 0, which means that the electric slewing system does not move at all.

7. The control method for an electric rotary system based on a hydraulic system according to claim 5, characterized in that: The rotation of the control handle from the center position to a specified direction represents a leftward angle operation, where k > 0, and k = 1 when the handle reaches the limit position.

8. The control method for an electric rotary system based on a hydraulic system according to claim 5, characterized in that: The movement of the rotary operating handle from the center position to the opposite direction represents a rightward rotary operation, where k < 0, and k = -1 when the handle reaches the limit position.

9. The control method for an electric rotary system based on a hydraulic system according to claim 4, characterized in that: The method for obtaining the additional torque value n2 includes the following steps: Based on the current rotational speed of the rotary motor, the actual rotational speed v1 of the rotary platform is calculated by converting the transmission ratio of the reducer. The target leftward rotation speed of the rotary platform is obtained by measuring the signal value from the pressure sensor, and is defined as v2 = k * v max v max This is the design value for the maximum speed of the slewing platform; The input variables of the fuzzy control algorithm are the difference e between v1 and v2, and the rate of change e′ of the difference. According to the fuzzy control rules, the output variable is the additional torque value n2.

10. The control method for an electric rotary system based on a hydraulic system according to claim 4, characterized in that: The method for obtaining fuzzy control rules is as follows: The fuzzy subset of the difference e is defined as {-0.2,-0.1,0,0.1,0.2}, and the corresponding linguistic variables are {vs,s,z,b,vb}. The fuzzy subset of the rate of change e′ is defined as {-2,-1,0,1,2}, and the corresponding linguistic variables are {vs,s,z,b,vb}. The fuzzy subset of the additional torque value n2 is defined as {-100,-50,0,50,100}, and the corresponding linguistic variables are {vs,s,z,b,vb}. Fuzzy control rules are established, as detailed in Table 1. Table 1

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