Excavator electric rotation system and control method

Abstract

The invention belongs to the technical field of excavator rotation systems, and particularly relates to an excavator electric rotation system and a control method, the excavator electric rotation system comprises a handle, a tilt angle sensor, a rotation angle sensor, a weighing system, a whole machine controller, a power supply system, a brake resistor, a rotation motor and a brake; wherein the handle and the sensor are connected with an input port of the whole machine controller; the output port of the complete machine controller is connected with the control port of the brake, and the communication port of the complete machine controller is connected with the communication ports of the motor controller and the weighing system; the motor controller is connected with the power supply system, the rotary motor and the brake resistor, and the rotary motor is mechanically connected with the brake and the speed reducer. The acceleration stability in the rotation process is improved, the acceleration stability in the rotation process is improved, the stability in the rotation stopping process is improved, the problem that the regenerative braking force is insufficient when the motor is at a low speed is solved, the application working condition is wider, and the system is more reliable.

Description

Technical Field

[0001] The present invention belongs to the technical field of excavator slewing systems, and in particular relates to an excavator electric slewing system and a control method. Background Art

[0002] In the hydraulic slewing system of excavators, the maximum working pressure of the slewing motor cannot be adjusted during the rotation process, resulting in large differences in acceleration and deceleration speeds under different moments of inertia, making it impossible to achieve stable acceleration and stable deceleration. The precise operation of the slewing system depends on the driver's experience. On the other hand, with the development of unmanned and remote control technology, the uncertainty of this hydraulic slewing system is difficult to meet the requirements of unmanned precise positioning.

[0003] The electric slewing system, thanks to the flexibility of motor control, can adopt more control methods and strategies, but according to the working characteristics of the excavator slewing system, there are still some technical problems that need to be solved. For example, the motor can be braked by energy consumption braking, electromagnetic braking, mechanical braking and other methods, and the control strategy needs to be formulated according to the working characteristics. For example, when the excavator is working on a slope, the slewing system needs to be braked to prevent the slewing from slipping. The use of long-term energy consumption braking will cause the motor to heat up and lose energy. The use of electromagnetic and mechanical braking will cause the excavator's workload impact to affect its life.

[0004] For the electric rotary system, on the one hand, the system needs to be designed according to the working requirements of the equipment, and on the other hand, the control method needs to be designed according to the characteristics of the working conditions. Summary of the invention

[0005] In order to solve the above technical problems, the present invention provides an electric swing system and control method for an excavator, which utilizes sensors, controllers, and actuators to sense changes in the working state of the excavator, and through the algorithm of the built-in controller, realizes deceleration, stopping, parking, and safe and smooth swing control of the electric swing system under special working conditions.

[0006] To achieve the above object, the present invention adopts the following technical solution:

[0007] An electric swing system for an excavator, comprising: a handle, a tilt sensor I, a tilt sensor II, a tilt sensor III, a tilt sensor IV, a swing angle sensor, a weighing system, a whole machine controller, a power supply system, a braking resistor, a swing motor, an electromagnetic brake, a mechanical brake, and a reducer; wherein the handle, the tilt sensor I, the tilt sensor II, the tilt sensor III, the tilt sensor IV, and the swing angle sensor are connected to an input port of the whole machine controller; an output port of the whole machine controller is connected to control ports of the electromagnetic brake and the mechanical brake, and a communication port of the whole machine controller is connected to a motor controller and a communication port of the weighing system; the motor controller is connected to the power supply system, the swing motor, and the braking resistor, and the swing motor is mechanically connected to the electromagnetic brake, the mechanical brake, and the reducer;

[0008] The motor controller receives the motor control mode instruction sent by the whole machine controller, and performs speed control and torque control of the rotary motor.

[0009] Further, a control method of an electric swing system of an excavator includes a start control method, a braking control method during movement, and a braking control method during stop;

[0010] The startup control method: during startup, at the initial acceleration stage t1, the rotation angular acceleration of the rotary motor is designed to To control the target, the whole machine controller calculates and outputs the required rotary motor drive torque to the motor controller; when the rotary motor target speed minus the actual speed is lower than When the whole machine controller sends the rotary motor control mode to the speed control mode, the motor speed reaches the target speed according to the design rule;

[0011] The braking control method during motion: when the actual speed of the rotary motor minus the target speed is less than When the actual speed of the rotary motor minus the target speed is greater than or equal to Or the actual speed of the rotary motor is greater than When braking, regenerative braking is used;

[0012] The braking control method when stopping is as follows: when the excavator vehicle is not moving, the electric swing system adopts mechanical braking, otherwise, the electric swing system adopts torque braking.

[0013] Furthermore, the method for calculating the driving torque of the rotary motor in the startup control method is:

[0014] Calculate the required rotary motor drive torque based on the real-time moment of inertia of the whole machine, the design value of the whole machine rotation angular acceleration, and the whole machine inclination angle:

[0015]

[0016] Where:

[0017] -Convert the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor;

[0018] -Design value of angular acceleration when the rotary motor accelerates;

[0019] -Convert the tilt torque of the whole machine to the torque of the output shaft of the rotary motor;

[0020] -The friction torque of the whole machine is converted to the rotation torque of the output shaft of the rotary motor.

[0021] Furthermore, the calculation method of converting the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor is:

[0022]

[0023] Where:

[0024] -The unchanged part of the moment of inertia of the whole machine relative to the rotation center of the whole machine, converted to the moment of inertia of the output shaft of the rotary motor;

[0025] - The moment of inertia of the component measured by the inclination sensor 1 relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0026] -The moment of inertia of the component measured by the inclination sensor II relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0027] - The moment of inertia of the component measured by the inclination sensor III relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0028] -The moment of inertia of the material measured by the weighing system relative to the center of rotation of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor.

[0029] Furthermore, in the braking control method during motion, regenerative braking is to control the rotary motor to convert into a generator working state, generate a torque opposite to the rotation direction, and generate electrical energy at the same time.

[0030] Furthermore, in the braking control method during motion, when the regenerative braking of the rotary motor is working, the regenerated electric energy is consumed through the braking resistor via the motor controller.

[0031] Furthermore, in the braking control method during motion, when the regenerative braking of the rotary motor is working, the regenerated electric energy is input into the power supply system through the motor controller.

[0032] Furthermore, in the braking control method during motion, the calculation method of the regenerative braking torque of the rotary motor is:

[0033] Calculate the required rotary motor drive torque based on the real-time moment of inertia of the whole machine, the design value of the whole machine rotation angular acceleration, the whole machine inclination angle, etc.:

[0034]

[0035] Where: -Convert the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor;

[0036] -Design value of angular acceleration when the rotary motor decelerates;

[0037] -Convert the tilt torque of the whole machine to the torque of the output shaft of the rotary motor;

[0038] -The friction torque of the whole machine is converted to the rotation torque of the output shaft of the rotary motor.

[0039] The advantages of the present invention compared with the prior art are:

[0040] The present invention adopts dynamic rotation inertia to calculate the real-time torque value of the rotary motor, which can improve the acceleration stability of the rotation process.

[0041] The present invention adopts a combination of regenerative braking and electromagnetic braking when stopping the rotary motion, thereby avoiding the problem of insufficient regenerative braking force of the motor at low speed.

[0042] The present invention adopts dynamic rotation inertia to calculate the real-time deceleration torque value of the rotary motor when the rotary motion stops and brakes, so as to improve the stability of the rotation stopping process.

[0043] The present invention adopts a combination of torque braking and mechanical braking when the rotary system stops, which is applicable to a wider range of working conditions and makes the system more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 This is a schematic diagram of the structure of the electric swing system of the excavator;

[0045] Figure 2 This is a schematic diagram of the installation positions of various sensors in the electric swing system of the excavator;

[0046] Figure 3 This is an example of the angular acceleration and angular velocity of a rotary motor;

[0047] Figure 2 Middle: 1. Tilt sensor I; 2. Tilt sensor II; 3. Tilt sensor III; 4. Tilt sensor IV; 5. Rotation angle sensor;

[0048] Figure 3 In: a. angular acceleration of the rotary motor; b. angular velocity of the rotary motor. DETAILED DESCRIPTION

[0049] The technical solution of the present invention is described in detail below through the accompanying drawings and specific embodiments. It should be understood that the embodiments of the present application and the specific features in the embodiments are detailed descriptions of the technical solution of the present application, rather than limitations on the technical solution of the present application. In the absence of conflict, the embodiments of the present application and the technical features in the embodiments can be combined with each other.

[0050] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0051] like Figures 1 to 3 As shown, the present invention provides an electric swing system for an excavator. This system uses sensors, controllers, and actuators to sense changes in the working state of the excavator, and through the algorithm of the built-in controller, it realizes the deceleration, stopping, parking, and safe and smooth swing control of the electric swing system under special working conditions.

[0052] An electric rotary system for an excavator includes: a handle, a tilt sensor I1, a tilt sensor II2, a tilt sensor III3, a tilt sensor IV4, a rotary angle sensor 5, a weighing system, a whole machine controller, a motor controller, a power supply system, a braking resistor, a rotary motor, an electromagnetic brake, a mechanical brake, and a reducer. The handle, the tilt sensor I1, the tilt sensor II2, the tilt sensor III3, the tilt sensor IV4, and the rotary angle sensor 5 are connected to the input port of the whole machine controller, the output port of the whole machine controller is connected to the control port of the electromagnetic brake and the mechanical brake, and the communication port of the whole machine controller is connected to the communication port of the motor controller and the weighing system. The motor controller is connected to the power supply system, the rotary motor, and the braking resistor, and the rotary motor is mechanically connected to the electromagnetic brake, the mechanical brake, and the reducer.

[0053] The handle outputs the forward rotation and reverse rotation control signals and signal sizes.

[0054] The inclination sensors I1, II2, III3 and IV4 are respectively installed on the excavator bucket, arm, boom and turntable for testing the bucket attitude angle, arm attitude angle, boom attitude angle and turntable attitude angle.

[0055] The rotation angle sensor 5 is installed on the excavator turntable to test the rotation angle of the turntable and the rotation angular acceleration of the rotary motor.

[0056] The weighing system is used to weigh the materials in the excavator bucket and can send the weighing data to the whole machine controller.

[0057] The whole machine controller collects the inclination sensor signal and communicates with the weighing system and the motor controller.

[0058] The power supply system is used to supply power to the electric slewing system.

[0059] The braking resistor is used to consume the electric energy generated by the motor during regenerative braking of the motor.

[0060] The rotary motor is used to drive the rotary system to rotate.

[0061] The electromagnetic brake can control the braking force through an electrical control signal.

[0062] The mechanical brake is used to brake the electric swing system in a mechanical manner.

[0063] The speed reducer is used to convert the high speed output by the rotary motor into a low speed for driving the device to rotate.

[0064] The whole machine controller collects the parameters of inclination sensor I1, inclination sensor II2, inclination sensor III3, and inclination sensor IV4, and then calculates the moment of inertia of the whole machine in the current state in real time according to the structure and center of gravity parameters of each moving part of the excavator. By communicating with the weighing system, the mass of the material in the current bucket is obtained, and the center of gravity of the material is assumed to coincide with the center of gravity of the bucket, and the moment of inertia of the material is calculated.

[0065] The starting control method of the electric swing system of the excavator is to use the design value of the angular acceleration of the swing motor at the initial acceleration stage t1. To achieve the control target, the whole machine controller calculates and outputs the required rotary motor drive torque to the motor controller. When the whole machine controller sends the rotary motor control mode to the speed control mode, the motor speed reaches the target speed according to the design rule.

[0066] Represents the degree to which the actual speed of the starting process is close to the target speed. It is the design value. When the target speed of the rotary motor minus the actual speed < , it means the actual speed is close to the target speed.

[0067] The calculation method of the rotary motor driving torque is:

[0068] Calculate the required rotary motor drive torque based on the real-time moment of inertia of the whole machine, the design value of the whole machine rotation angular acceleration, the whole machine inclination angle, etc.:

[0069]

[0070] Where:

[0071] -Convert the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor;

[0072] -Design value of angular acceleration when the rotary motor accelerates;

[0073] - The tilt torque of the whole machine is converted to the torque of the output shaft of the rotary motor. The torque generated by the tilt is determined in real time through the inclination sensor IV, the rotation angle sensor 5, the state of the whole machine affected by gravity, the transmission ratio, etc.;

[0074] -The friction torque of the whole machine is converted to the rotation torque of the output shaft of the rotary motor.

[0075] The calculation method of converting the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor is:

[0076]

[0077] Where:

[0078] -The unchanged part of the moment of inertia of the whole machine relative to the rotation center of the whole machine, converted to the moment of inertia of the output shaft of the rotary motor;

[0079] - The moment of inertia of the component measured by the inclination sensor 1 relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0080] -The moment of inertia of the component measured by the inclination sensor II relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0081] - The moment of inertia of the component measured by the inclination sensor III relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0082] -The moment of inertia of the material measured by the weighing system relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor;

[0083] The braking control method of the electric swing system of the excavator is to control the actual speed of the swing motor minus the target speed when the actual speed of the swing motor is less than the target speed. When the actual speed of the rotary motor minus the target speed is greater than or equal to Or the actual speed of the rotary motor is greater than When braking, regenerative braking is used.

[0084] , Indicates the degree to which the actual speed of the motion process is close to the target speed, which is the design value. Indicates that the actual speed of the rotary motor is close to the target speed. Indicates that the actual speed of the rotary motor is high. < The actual speed of the rotary motor minus the target speed is less than When the actual speed of the rotary motor is low, the regenerative braking force is too small due to the low speed, and electromagnetic braking needs to be added to provide greater braking force. The actual speed of the rotary motor minus the target speed is greater than or equal to Or the actual speed of the rotary motor is greater than When the actual speed of the rotary motor is no less than the target speed, or is much higher than the target speed, the regenerative braking force is large and can meet the braking demand, and regenerative braking is used.

[0085] Regenerative braking is the process of controlling the rotary motor to convert it into a generator, generating torque in the opposite direction of rotation while generating electrical energy.

[0086] When the regenerative braking of the swing motor takes effect, the regenerated electric energy is consumed through the braking resistor via the motor controller.

[0087] When the regenerative braking of the rotary motor takes effect, the regenerated electric energy is input into the power supply system through the motor controller.

[0088] The calculation method of the regenerative braking torque of the swing motor is:

[0089] Calculate the required rotary motor drive torque based on the machine's rotational inertia, the machine's rotational angular acceleration design value, the machine's inclination angle, etc.:

[0090]

[0091] In the formula -Convert the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor;

[0092] -Design value of angular acceleration when the rotary motor decelerates;

[0093] -Convert the tilt torque of the whole machine to the torque of the output shaft of the rotary motor;

[0094] -The friction torque of the whole machine is converted to the rotation torque of the output shaft of the rotary motor.

[0095] The braking control method when the electric swing system of the excavator stops is that when the excavator vehicle is not moving, the electric swing system adopts mechanical braking, otherwise, the electric swing system adopts torque braking.

[0096] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. An electric slewing system for an excavator, characterized in that: include: Handle, inclination sensor I, inclination sensor II, inclination sensor III, inclination sensor IV, rotation angle sensor, weighing system, whole machine controller, power supply system, braking resistor, rotary motor, electromagnetic brake, mechanical brake, reducer; wherein, the handle, inclination sensor I, inclination sensor II, inclination sensor III, inclination sensor IV, rotation angle sensor are connected to the input port of the whole machine controller; the output port of the whole machine controller is connected to the control port of the electromagnetic brake and the mechanical brake, and the communication port of the whole machine controller is connected to the motor controller and the communication port of the weighing system; the motor controller is connected to the power supply system, the rotary motor, and the braking resistor, and the rotary motor is mechanically connected to the electromagnetic brake, the mechanical brake, and the reducer; The motor controller receives the motor control mode instruction sent by the whole machine controller, and performs speed control and torque control of the rotary motor.

2. A control method for an electric swing system of an excavator according to claim 1, characterized in that: Including starting control method, braking control method during motion and braking control method during stop; The startup control method: during startup, at the initial acceleration stage t1, the rotation angular acceleration of the rotary motor is designed to To control the target, the whole machine controller calculates and outputs the required rotary motor drive torque to the motor controller; when the rotary motor target speed minus the actual speed is lower than When the whole machine controller sends the rotary motor control mode to the speed control mode, the motor speed reaches the target speed according to the design rule; The braking control method during motion: when the actual speed of the rotary motor minus the target speed is less than When the actual speed of the rotary motor minus the target speed is greater than or equal to Or the actual speed of the rotary motor is greater than When braking, regenerative braking is used; The braking control method when stopping is as follows: when the excavator vehicle is not moving, the electric swing system adopts mechanical braking, otherwise, the electric swing system adopts torque braking.

3. The control method of the electric swing system of an excavator according to claim 2, characterized in that: The calculation method of the rotary motor driving torque in the startup control method is: Calculate the required rotary motor drive torque based on the real-time moment of inertia of the whole machine, the design value of the whole machine rotation angular acceleration, and the whole machine inclination angle: Where: -Convert the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor; -Design value of angular acceleration when the rotary motor accelerates; -Convert the tilt torque of the whole machine to the torque of the output shaft of the rotary motor; -The friction torque of the whole machine is converted to the rotation torque of the output shaft of the rotary motor.

4. The control method of the electric swing system of an excavator according to claim 3, characterized in that: The calculation method of converting the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor is: Where: -The unchanged part of the moment of inertia of the whole machine relative to the center of rotation of the whole machine, converted to the moment of inertia of the output shaft of the rotary motor; - The moment of inertia of the component measured by the inclination sensor 1 relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor; -The moment of inertia of the component measured by the inclination sensor II relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor; - The moment of inertia of the component measured by the inclination sensor III relative to the rotation center of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor; -The moment of inertia of the material measured by the weighing system relative to the center of rotation of the whole machine is converted to the moment of inertia of the output shaft of the rotary motor.

5. The control method of the electric swing system of an excavator according to claim 2, characterized in that: In the braking control method during motion, regenerative braking is to control the rotary motor to convert into a generator working state, generate a torque opposite to the rotation direction, and generate electrical energy at the same time.

6. The control method of the electric swing system of an excavator according to claim 2, characterized in that: In the braking control method during motion, when the regenerative braking of the rotary motor is in operation, the regenerated electric energy is consumed by the braking resistor through the motor controller.

7. The control method of the electric swing system of an excavator according to claim 2, characterized in that: In the braking control method during motion, when the regenerative braking of the rotary motor is in operation, the regenerated electric energy is input into the power supply system through the motor controller.

8. The control method of the electric swing system of an excavator according to claim 2, characterized in that: In the braking control method during motion, the calculation method of the regenerative braking torque of the rotary motor is: Calculate the required rotary motor drive torque based on the machine's rotational inertia, the machine's rotational angular acceleration design value, the machine's inclination angle, etc.: Where: -Convert the real-time moment of inertia of the whole machine to the moment of inertia of the output shaft of the rotary motor; -Design value of angular acceleration when the rotary motor decelerates; -Convert the tilt torque of the whole machine to the torque of the output shaft of the rotary motor; -The friction torque of the whole machine is converted to the rotation torque of the output shaft of the rotary motor.

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