Compensation control system for electric swing brake vibration on excavator

Abstract

Aiming at the problems and shortcomings of the electric swing of pure electric excavators, the present invention proposes a compensation control system that utilizes a hydraulic energy storage device and hydraulic motor displacement control to effectively solve the brake jitter phenomenon caused by the difficulty of the braking control parameters of the electric swing system matching the rotational inertia of all working conditions and the negative damping electromagnetic characteristics of the motor brake. The compensation inertia is synthesized by equivalently combining the difference between the maximum rotational inertia and the rotational inertia of different working conditions and the negative damping electromagnetic torque of the motor brake, so that the rotational inertia of the compensated system matches the maximum inertia of the swing device to the greatest extent, thereby eliminating the brake jitter phenomenon.

Description

Technical Field

[0001] The invention belongs to the technical field of electric excavator driving, and in particular relates to a compensating control system for electric slewing brake vibration on an excavator. Background Art

[0002] In the field of construction machinery, hydraulic excavators, which use hydraulic energy as the driving force for their actuators, are the most widely used earthmoving machines. During excavation operations, traditional hydraulic excavators experience high rotational frequency and high moments of inertia. This results in a significant amount of braking energy being consumed by the hydraulic valve ports, wasting energy and causing heating in the hydraulic system and shortening component life. Recovering brake energy from high-frequency operating mechanisms with high moments of inertia is an effective measure for energy conservation and consumption reduction in excavator hydraulic systems. This high moment of inertia braking energy can be recovered by converting it into hydraulic energy, storing it in accumulators for subsequent use or directly driving hydraulic components, or by converting it into electrical energy, storing it in accumulators for subsequent use. Sinotruk Group has proposed a solution for recovering braking energy from a hydraulic motor by pumping it back into an accumulator during braking (CN101858094A); Sunward Intelligent Technology has proposed a method for recovering braking energy from a swing hydraulic motor by using an electric motor during braking (CN103882901A); and Changlin Machinery has applied for a patent for converting swing braking energy into hydraulic energy and storing it in an accumulator for utilization during the next swing start (CN105545884A). Hybrid and pure electric excavators mostly use electric motors to directly drive the swing mechanism, storing the braking kinetic energy in supercapacitors and batteries for energy recovery. Due to the excellent control performance of electric motor drive and the well-established application of energy recovery and management in storage batteries in electric vehicles, excavator manufacturers such as Hitachi Construction Machinery, Komatsu, Caterpillar, Sany Heavy Industry, Zoomlion, Sunward Intelligent Technology, and Liugong have launched electric swing test models since 2004.

[0003] The electric swing system for excavators effectively addresses the problem of traditional hydraulic excavators dissipating kinetic energy in the hydraulic valve ports during swing braking. Due to the varying swing radius and excavated material volume, the moment of inertia of the upper, high-inertia swing unit exhibits irregular variations. Due to the electromagnetic characteristics between the rotor and stator, the swing motor can generate severe negative damping during transient conditions. Because the system's braking control parameters struggle to match the moment of inertia under all operating conditions and the electromagnetic characteristics of the motor's negative braking damping, the upper, high-inertia swing unit experiences brake judder during braking. This degrades the braking controllability of the electric swing system and reduces the life of the swing system components. Summary of the Invention

[0004] Aiming at the problems and shortcomings of the electric swing of pure electric excavators, the present invention proposes a compensation control system that utilizes a hydraulic energy storage device and hydraulic motor displacement control to effectively solve the brake jitter phenomenon caused by the difficulty of the braking control parameters of the electric swing system matching the rotational inertia of all working conditions and the negative damping electromagnetic characteristics of the motor brake. The compensation inertia is synthesized by equivalently combining the difference between the maximum rotational inertia and the rotational inertia of different working conditions and the negative damping electromagnetic torque of the motor brake, so that the rotational inertia of the compensated system matches the maximum inertia of the swing device to the greatest extent, thereby eliminating the brake jitter phenomenon.

[0005] In order to achieve the above object, the technical solution of the present invention is:

[0006] A compensating control system for electric swing brake vibration on an excavator vehicle includes: a power battery 1, a bidirectional DC-DC inverter 2, a swing motor 3, a swing reducer 4, a first overflow safety valve 5, a second overflow safety valve 6, a first oil replenishment check valve 7, a second oil replenishment check valve 8, an oil replenishment tank 9, and an electronic reversing module 10; further includes: an angular displacement sensor 11, a hydraulic motor 12, a first two-position two-way proportional reversing valve 13, a second two-position two-way proportional reversing valve 14, a pressure sensor 15, a variable damping throttle valve 16, a first swing oil tank 17, a second swing oil tank 18, an auxiliary swing controller 19, and a Y-type three-position four-way reversing valve 20;

[0007] The M-side output shaft of the rotary motor 3 is connected to the rotary reducer 4, the N-side input shaft of the rotary motor 3 is connected to the hydraulic motor 12, and the rotary motor 3 is connected to the power battery 1 through the bidirectional DC-DC inverter 2;

[0008] The A oil port of the hydraulic motor 12 is connected to the C oil port of the first two-position two-way proportional directional reversing valve 13, and the B oil port of the hydraulic motor 12 is connected to the K oil port of the second two-position two-way proportional directional reversing valve 14; the D oil port of the first two-position two-way proportional directional reversing valve 13 is connected to the E oil port of the Y-type function three-position four-way directional reversing valve 20, and the J oil port of the second two-position two-way proportional reversing valve 14 is connected to the F oil port of the Y-type function three-position four-way directional reversing valve 20; the G oil port of the Y-type function three-position four-way directional reversing valve 20 is connected to the oil inlet of the pressure sensor 15 and the variable damping throttle valve 16, the oil outlet of the variable damping throttle valve 16 is connected to the first rotary oil tank 17, and the H oil port of the Y-type function three-position four-way directional reversing valve 20 is connected to the second rotary oil tank 18;

[0009] The oil port A of the hydraulic motor 12 is connected to the oil inlet of the first overflow safety valve 5, the oil port B of the hydraulic motor 12 is connected to the oil inlet of the second overflow safety valve 6, the oil port A of the hydraulic motor 12 is connected to the oil outlet of the first oil-supply check valve 7, and the oil port B of the hydraulic motor 12 is connected to the oil outlet of the second oil-supply check valve 8; the oil outlets of the first overflow safety valve 5 and the second overflow safety valve 6 are connected to the oil supply tank 9, and the oil inlets of the first oil-supply check valve 7 and the second oil-supply check valve 8 are connected to the oil supply tank 9;

[0010] The auxiliary rotation controller 19 is respectively connected to the feedback signal circuits of the angular displacement sensor 11, the pressure sensor 15, and the electronic reversing module 10; the auxiliary rotation controller 19 is respectively connected to the control signal circuits of the hydraulic motor 12, the first two-position two-way proportional reversing valve 13, the second two-position two-way proportional reversing valve 14, the Y-type three-position four-way reversing valve 20, and the bidirectional DC-DC inverter 2;

[0011] The electronic reversing module 10 sends a steering signal to the auxiliary slewing controller 19. The variable damping throttle valve 16 provides a passive power source for compensating the braking torque. The pressure sensor 15 monitors the compensating pressure at the oil inlet of the variable damping throttle valve 16. The hydraulic motor 12 provides auxiliary braking torque for the electric slewing system. The angular displacement sensor 11 detects the angle of the output shaft of the slewing reducer 4 and sends it to the auxiliary slewing controller 19. The auxiliary slewing controller 19 sends a displacement control signal to the hydraulic motor 12. The auxiliary slewing controller 19 sends a braking control signal to the first two-position two-way proportional directional reversing valve 13 and the second two-position two-way proportional directional reversing valve 14. The auxiliary slewing controller 19 controls the Y-type three-position four-way directional reversing valve 20 to enable the variable damping throttle valve 16 to compensate for the braking torque during both forward and reverse braking.

[0012] The slewing motor 3 serves as the main driving device and provides driving and braking torque for the slewing system. When the slewing motor is in the braking condition, the compensation control system for the electric slewing brake vibration of the excavator uses the variable damping throttle valve 16 and the hydraulic motor 12 to compensate for the change in the rotational inertia of the slewing device, so that the rotational inertia of the compensated system matches the maximum inertia of the slewing device to the greatest extent, thereby suppressing and eliminating the braking vibration.

[0013] The present invention has the following beneficial effects:

[0014] 1) The present invention can effectively solve the problem of brake jitter of the pure electric upper large inertia rotary device during braking because the current brake control parameters cannot match the current working condition moment of inertia value.

[0015] 2) The present invention can simplify the control parameters of the electric slewing system of the vehicle slewing mechanism of the current pure electric excavator. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the system principle of Example 1 of the present invention.

[0017] Figure 2 This is a schematic diagram of the system principle of Example 2 of the present invention.

[0018] In the figure, 1-power battery, 2-bidirectional DC-DC inverter, 3-rotating motor, 4-rotating reducer, 5-I overflow safety valve, 6-II overflow safety valve, 7-I oil supply check valve, 8-II oil supply check valve, 9-oil supply tank, 10-electronic reversing module, 11-angular displacement sensor, 12-hydraulic motor, 13-I two-position two-way proportional reversing valve, 14-II two-position two-way proportional reversing valve, 15-pressure sensor, 16-variable damping throttle valve, 17-I rotary oil tank, 18-II rotary oil tank, 19-auxiliary rotary controller, 20-Y-type functional three-position four-way reversing valve. DETAILED DESCRIPTION

[0019] The following describes the detailed technical solution of the present invention in conjunction with the accompanying drawings: Example 1

[0020] like Figure 1 As shown, a compensation control system for electric swing brake vibration on an excavator includes: a power battery 1, a bidirectional DC-DC inverter 2, a swing motor 3, a swing reducer 4, a first overflow safety valve 5, a second overflow safety valve 6, a first oil replenishment check valve 7, a second oil replenishment check valve 8, an oil replenishment tank 9, and an electronic reversing module 10; it also includes: an angular displacement sensor 11, a hydraulic motor 12, a first two-position two-way proportional reversing valve 13, a second two-position two-way proportional reversing valve 14, a pressure sensor 15, a variable damping throttle valve 16, a first swing oil tank 17, a second swing oil tank 18, an auxiliary swing controller 19, and a Y-type three-position four-way reversing valve 20;

[0021] The M-side output shaft of the rotary motor 3 is connected to the rotary reducer 4, the N-side input shaft of the rotary motor 3 is connected to the hydraulic motor 12, and the rotary motor 3 is connected to the power battery 1 through the bidirectional DC-DC inverter 2;

[0022] The A oil port of the hydraulic motor 12 is connected to the C oil port of the first two-position two-way proportional directional reversing valve 13, and the B oil port of the hydraulic motor 12 is connected to the K oil port of the second two-position two-way proportional directional reversing valve 14; the D oil port of the first two-position two-way proportional directional reversing valve 13 is connected to the E oil port of the Y-type function three-position four-way directional reversing valve 20, and the J oil port of the second two-position two-way proportional reversing valve 14 is connected to the F oil port of the Y-type function three-position four-way directional reversing valve 20; the G oil port of the Y-type function three-position four-way directional reversing valve 20 is connected to the oil inlet of the pressure sensor 15 and the variable damping throttle valve 16, the oil outlet of the variable damping throttle valve 16 is connected to the first rotary oil tank 17, and the H oil port of the Y-type function three-position four-way directional reversing valve 20 is connected to the second rotary oil tank 18;

[0023] The oil port A of the hydraulic motor 12 is connected to the oil inlet of the first overflow safety valve 5, the oil port B of the hydraulic motor 12 is connected to the oil inlet of the second overflow safety valve 6, the oil port A of the hydraulic motor 12 is connected to the oil outlet of the first oil-supply check valve 7, and the oil port B of the hydraulic motor 12 is connected to the oil outlet of the second oil-supply check valve 8; the oil outlets of the first overflow safety valve 5 and the second overflow safety valve 6 are connected to the oil supply tank 9, and the oil inlets of the first oil-supply check valve 7 and the second oil-supply check valve 8 are connected to the oil supply tank 9;

[0024] The auxiliary rotation controller 19 is respectively connected to the feedback signal circuits of the angular displacement sensor 11, the pressure sensor 15, and the electronic reversing module 10; the auxiliary rotation controller 19 is respectively connected to the control signal circuits of the hydraulic motor 12, the first two-position two-way proportional reversing valve 13, the second two-position two-way proportional reversing valve 14, the Y-type three-position four-way reversing valve 20, and the bidirectional DC-DC inverter 2;

[0025] The electronic reversing module 10 sends a steering signal to the auxiliary rotation controller 19, the variable damping throttle valve 16 provides a passive power source for compensating the braking torque, the pressure sensor 15 monitors the compensation pressure at the oil inlet of the variable damping throttle valve 16, the hydraulic motor 12 provides auxiliary braking torque for the electric rotation system, the angular displacement sensor 11 detects the angle of the output shaft of the rotary reducer 4 and sends it to the auxiliary rotation controller 19, the auxiliary rotation controller 19 sends a displacement control signal to the hydraulic motor 12, the auxiliary rotation controller 19 sends a braking control signal to the I two-position two-way proportional reversing valve 13 and the II two-position two-way proportional reversing valve 14, and the auxiliary rotation controller 19 controls the Y-type functional three-position four-way reversing valve 20 to enable the variable damping throttle valve 16 to compensate for the braking torque during forward and reverse braking.

[0026] The slewing motor 3 serves as the main driving device and provides driving and braking torque for the slewing system. When the slewing motor is in the braking condition, the compensation control system for the electric slewing brake vibration of the excavator uses the variable damping throttle valve 16 and the hydraulic motor 12 to compensate for the change in the rotational inertia of the slewing device, so that the rotational inertia of the compensated system matches the maximum inertia of the slewing device to the greatest extent, thereby suppressing and eliminating the braking vibration. Example 2

[0027] like Figure 2 As shown, an electric swing brake vibration compensation control system for the slewing mechanism of an excavator includes: a power battery 1, a bidirectional DC-DC inverter 2, a swing motor 3, a swing reducer 4, a first overflow safety valve 5, a second overflow safety valve 6, a first oil replenishment check valve 7, a second oil replenishment check valve 8, an oil replenishment tank 9, and an electronic reversing module 10; it also includes: an angular displacement sensor 11, a hydraulic motor 12, a pressure sensor 15, a variable damping throttle valve 16, a first swing oil tank 17, a second swing oil tank 18, an auxiliary swing controller 19, a two-position two-way solenoid valve 21, and an O-type three-position four-way proportional reversing valve 22;

[0028] The M-side output shaft of the rotary motor 3 is connected to the rotary reducer 4, the N-side input shaft of the rotary motor 3 is connected to the hydraulic motor 12, and the rotary motor 3 is connected to the power battery 1 through the bidirectional DC-DC inverter 2;

[0029] The A oil port of the hydraulic motor 12 is connected to the C oil port of the 2-position 2-way solenoid valve 21, and the B oil port of the hydraulic motor 12 is connected to the D oil port of the 2-position 2-way solenoid valve 21; the C oil port of the 2-position 2-way solenoid valve 21 is connected to the E oil port of the O-type function 3-position 4-way proportional reversing valve 22, and the D oil port of the 2-position 2-way solenoid valve 13 is connected to the F oil port of the O-type function 3-position 4-way proportional reversing valve 22; the G oil port of the O-type function 3-position 4-way proportional reversing valve 22 is connected to the oil inlet of the pressure sensor 15 and the variable damping throttle valve 16, the oil outlet of the variable damping throttle valve 16 is connected to the first rotary oil tank 17, and the H oil port of the O-type function 3-position 4-way proportional reversing valve 22 is connected to the second rotary oil tank 18;

[0030] The oil port A of the hydraulic motor 12 is connected to the oil inlet of the first overflow safety valve 5, the oil port B of the hydraulic motor 12 is connected to the oil inlet of the second overflow safety valve 6, the oil port A of the hydraulic motor 12 is connected to the oil outlet of the first oil-supply check valve 7, and the oil port B of the hydraulic motor 12 is connected to the oil outlet of the second oil-supply check valve 8; the oil outlets of the first overflow safety valve 5 and the second overflow safety valve 6 are connected to the oil supply tank 9, and the oil inlets of the first oil-supply check valve 7 and the second oil-supply check valve 8 are connected to the oil supply tank 9;

[0031] The auxiliary rotation controller 19 is respectively connected to the feedback signal lines of the angular displacement sensor 11, the pressure sensor 15, and the electronic reversing module 10; the auxiliary rotation controller 19 is respectively connected to the control signal lines of the hydraulic motor 12, the two-position two-way solenoid valve 21, the O-type three-position four-way proportional reversing valve 22, and the bidirectional DC-DC inverter 2;

[0032] The electronic reversing module 10 sends a steering signal to the auxiliary swing controller 19. The variable damping throttle valve 16 provides a passive power source for compensating braking torque. The pressure sensor 15 monitors the compensating pressure at the oil inlet of the variable damping throttle valve 16. The hydraulic motor 12 provides auxiliary braking torque for the electric swing system. The angular displacement sensor 11 detects the rotation angle of the output shaft of the swing reducer 4 and sends it to the auxiliary swing controller 19. The auxiliary swing controller 19 sends a displacement control signal to the hydraulic motor 12. The auxiliary swing controller 19 controls the O-type three-position four-way proportional reversing valve 22 to enable the variable damping throttle valve 16 to compensate for braking torque during both forward and reverse braking.

[0033] The slewing motor 3 serves as the main driving device and provides driving and braking torque for the slewing system. When the slewing motor is in the braking condition, the compensation control system for the electric slewing brake vibration of the excavator uses the variable damping throttle valve 16 and the hydraulic motor 12 to compensate for the change in the rotational inertia of the slewing device, so that the rotational inertia of the compensated system matches the maximum inertia of the slewing device to the greatest extent, thereby suppressing and eliminating the braking vibration.

Claims

1. A compensating control system for electric slewing brake vibration on an excavator, comprising: A power battery (1), a bidirectional DC-DC inverter (2), a rotary motor (3), a rotary reducer (4), a first overflow safety valve (5), a second overflow safety valve (6), a first oil supply check valve (7), a second oil supply check valve (8), an oil supply tank (9), and an electronic reversing module (10); characterized in that it also includes: an angular displacement sensor (11), a hydraulic motor (12), a first two-position two-way proportional reversing valve (13), a second two-position two-way proportional reversing valve (14), a pressure sensor (15), a variable damping throttle valve (16), a first rotary oil tank (17), a second rotary oil tank (18), an auxiliary rotary controller (19), and a Y-type function three-position four-way reversing valve (20); The M-side output shaft of the rotary motor (3) is connected to the rotary reducer (4), the N-side input shaft of the rotary motor (3) is connected to the hydraulic motor (12), and the rotary motor (3) is connected to the power battery (1) via a bidirectional DC-DC inverter (2); The A oil port of the hydraulic motor (12) is connected to the C oil port of the first two-position two-way proportional directional reversing valve (13), and the B oil port of the hydraulic motor (12) is connected to the K oil port of the second two-position two-way proportional directional reversing valve (14); the D oil port of the first two-position two-way proportional directional reversing valve (13) is connected to the E oil port of the Y-type function three-position four-way directional reversing valve (20), and the J oil port of the second two-position two-way proportional directional reversing valve (14) is connected to the F oil port of the Y-type function three-position four-way directional reversing valve (20); the G oil port of the Y-type function three-position four-way directional reversing valve (20) is connected to the oil inlet of the pressure sensor (15) and the variable damping throttle valve (16), the oil outlet of the variable damping throttle valve (16) is connected to the first rotary oil tank (17), and the H oil port of the Y-type function three-position four-way directional reversing valve (20) is connected to the second rotary oil tank (18); The oil port A of the hydraulic motor (12) is connected to the oil inlet of the first overflow safety valve (5), the oil port B of the hydraulic motor (12) is connected to the oil inlet of the second overflow safety valve (6), the oil port A of the hydraulic motor (12) is connected to the oil outlet of the first oil replenishment check valve (7), and the oil port B of the hydraulic motor (12) is connected to the oil outlet of the second oil replenishment check valve (8); the oil outlets of the first overflow safety valve (5) and the second overflow safety valve (6) are connected to the oil replenishment tank (9), and the oil inlets of the first oil replenishment check valve (7) and the second oil replenishment check valve (8) are connected to the oil replenishment tank (9); The auxiliary rotation controller (19) is respectively connected to the feedback signal circuits of the angular displacement sensor (11), the pressure sensor (15), and the electronic reversing module (10); the auxiliary rotation controller (19) is respectively connected to the control signal circuits of the hydraulic motor (12), the first two-position two-way proportional reversing valve (13), the second two-position two-way proportional reversing valve (14), the Y-type function three-position four-way reversing valve (20), and the bidirectional DC-DC inverter (2); The electronic reversing module (10) sends a steering signal to the auxiliary rotary controller (19), the variable damping throttle valve (16) provides a passive power source for compensating the braking torque, the pressure sensor (15) monitors the compensation pressure of the oil inlet of the variable damping throttle valve (16), the hydraulic motor (12) provides an auxiliary braking torque for the electric rotary system, the angular displacement sensor (11) detects the rotation angle of the output shaft of the rotary reducer (4) and sends it to the auxiliary rotary controller (19), the auxiliary rotary controller (19) sends a displacement control signal to the hydraulic motor (12), the auxiliary rotary controller (19) sends a braking control signal to the first two-position two-way proportional reversing valve (13) and the second two-position two-way proportional reversing valve (14), and the auxiliary rotary controller (19) controls the Y-type three-position four-way reversing valve (20) to enable the variable damping throttle valve (16) to compensate for the braking torque in both forward and reverse braking processes; The slewing motor (3) serves as a main driving device to provide driving and braking torque for the slewing system. When the slewing motor is in a braking state, the compensation control system for the electric slewing brake vibration of the excavator is configured such that the variable damping throttle valve (16) and the hydraulic motor (12) compensate for the change in the rotational inertia of the slewing device, so that the rotational inertia of the compensated system matches the maximum inertia of the slewing device to the greatest extent, thereby achieving the suppression and elimination of the brake vibration.

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