Hoist parallel hot standby dual-loop speed control system and control method

Abstract

The application introduces a hoist parallel hot standby double-circuit speed control system and control method, comprising a detection feedback device, a hydraulic system and an electrical control device; two brake speed control circuits are arranged in the application, and a cutoff valve is arranged between the proportional reversing valve and the brake of the two brake speed control circuits; when a fault occurs, the cutoff valve performs a power-off action, can automatically cut off the circuit, physically isolates the fault circuit from the main circuit, and avoids affecting the normal working circuit of the brake system; the two brake speed control circuits can be switched and selected to work simultaneously or one standby by the electrical control device, and multiple working modes are realized; four one-way valves form a hydraulic bridge, which can ensure that when any accumulator is damaged and loses pressure, the system automatically shields the fault accumulator, works by another functional accumulator, realizes safe and stable braking, and ensures high reliability of the braking process.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of mine hoist safety brake control, in particular to a parallel hot standby double-loop speed control system and control method for a mine hoist. BACKGROUND

[0002] The mine hoist is a throat equipment for underground mining, and undertakes the important task of transporting minerals, equipment, materials and personnel between the surface and the underground. Its performance is very important for the safety production of the mine. The mine hoist system has large load, high speed, and many personnel, and has very high safety and reliability requirements. Safety braking refers to the emergency braking behavior of the mine hoist or hoist winch during operation to avoid safety accidents. The safety braking process is mainly completed by an electro-hydraulic braking system, and the braking performance and reliability of the electro-hydraulic braking system are important guarantees for the safety production of the mine hoist system.

[0003] Speed control mode and torque control mode are two safety braking modes used in the mine hoist system. The current speed control is a constant deceleration mode. During safety braking, the control effect of the closed-loop control system is used to keep the deceleration of the hoist system constant during the same braking process. During safety braking, the hoist system can be braked at a given constant deceleration under various loads, speeds and working conditions. At present, constant deceleration braking adopts single-loop and multi-channel modes. The single-loop mode is a closed-loop control system composed of a single braking device, an electro-hydraulic control device and a detection feedback device to realize the constant closed-loop braking control function of the hoist system during safety braking. The multi-channel braking mode is to redundantly connect the constant deceleration loop in parallel.

[0004] There are two main types of standby safety braking loops in the prior art: one is a speed braking mode standby constant torque two-stage braking mode. However, the constant torque two-stage braking control mode has lower safety and stability than the constant deceleration braking mode, and reduces the anti-slip conditions of large multi-rope friction hoists, resulting in increased weight of the hoist system, larger equipment specifications and power, and increased construction costs. The other is to use three braking loops in parallel to work simultaneously to perform constant deceleration braking. This mode has complex system control, and the three hydraulic loops and corresponding three control elements make the system large and inconvenient to maintain. The three constant deceleration braking channels have no isolation protection, and when a fault occurs, it will affect the remaining channels, which requires a large amount of feedback compensation adjustment. The hydraulic regulating valve and the energy storage element have a one-to-one correspondence, and cannot cross-channel adjust and compensate the pressure oil source. SUMMARY

[0005] The purpose of the present application is to overcome the deficiencies of the prior art, provide a hoist parallel hot standby double-loop speed control system and control method, realize two working modes of double-loop simultaneous operation and double-loop hot standby switching, and have the functions of isolation blocking of the fault loop and bridge type loop complementation of the emergency energy storage system.

[0006] The technical scheme adopted by the present application is:

[0007] A hoist parallel hot standby double-loop speed control system, comprising a detection feedback device, a hydraulic system and an electrical control device.

[0008] The detection feedback device comprises a hoist drum, a speed measuring element and a pressure sensor; the speed measuring element comprises a speed measuring machine and an encoder, and the speed measuring machine and the encoder are respectively arranged at the speed measuring points on both ends of the hoist drum.

[0009] The hydraulic system comprises an accumulator, a one-way valve, a proportional reversing valve, a cutoff valve, an electromagnetic reversing valve, a pressure regulating valve and a brake; two accumulators are arranged, the pressure oil output ports of the first accumulator are respectively connected to the output ends of the first one-way valve and the input end of the third one-way valve through pipelines, and the pressure oil output ports of the second accumulator are respectively connected to the output end of the second one-way valve and the input end of the fourth one-way valve; the four one-way valves form a hydraulic bridge circuit, the input ends of the first one-way valve and the second one-way valve are connected to an external pressure oil source through a pipeline; the output ends of the third one-way valve and the fourth one-way valve are connected to the pressure oil input ports of the first proportional reversing valve and the second proportional reversing valve through a pipeline; the output port of the first proportional reversing valve is connected to the input port of the first cutoff valve, and the output port of the second proportional reversing valve is connected to the input port of the second cutoff valve; the first proportional reversing valve and the first cutoff valve and the second proportional reversing valve and the second cutoff valve form two parallel brake speed control circuits; the output ports of the first cutoff valve and the second cutoff valve are connected to the input ports of two electromagnetic reversing valves through a pipeline, and the output ports of the two cutoff valves and the input ports of the two electromagnetic reversing valves are connected to the pressure regulating valve, and the pressure regulating valve is used to limit the upper limit value of the pre-brake working oil pressure of the system; the output ports of the two electromagnetic reversing valves are connected to the brake, and the two pressure sensors of the detection feedback device are arranged on the output port pipelines of the two electromagnetic reversing valves; and the brake is arranged on the brake disc of the hoist drum.

[0010] The electric control device comprises four operational amplifiers, two inputs of the first operational amplifier are connected with the tachometer and the encoder respectively, the output of the first operational amplifier is connected with one input of the third operational amplifier, the other input of the third operational amplifier receives the control program speed given instruction signal, two inputs of the second operational amplifier are connected with two pressure sensors on the output pipeline of the two electromagnetic reversing valves respectively, the output of the second operational amplifier and the output of the third operational amplifier are connected with two inputs of the fourth operational amplifier respectively, and the output of the fourth operational amplifier is connected with the electric control port of the two proportional reversing valves.

[0011] Specifically, the test interface and the pressure oil output pipeline of the two accumulators are respectively provided with pressure sensors; the pressure sensor on the test interface is used for monitoring the nitrogen pressure value and the charging time during the accumulator oil pressure unloading and the charging process, judging whether the accumulator bladder leaks, and giving a warning signal; and the pressure sensor on the pressure oil output pipeline is used for testing the oil pressure.

[0012] Specifically, a filter is arranged on the pipeline connected with the outputs of the third and fourth one-way valves.

[0013] Specifically, the electric control device comprises a control program and a fault self-diagnosis algorithm, which is used for monitoring, analyzing and judging the detection feedback device and the hydraulic system during the braking execution process, and realizing the fault self-diagnosis.

[0014] The application discloses a control method of a parallel hot standby double-circuit speed control system of a hoist.

[0015] Firstly, an external pressure oil source charges the two accumulators through the first and second one-way valves respectively; the first and second accumulators output pressure oil through the third and fourth one-way valves respectively, the outputs of the third and fourth one-way valves are connected and then connected with a filter, and the filter outlet divides into two paths to input pressure oil to the first and second proportional reversing valves respectively.

[0016] Secondly, the first operational amplifier of the electric control device receives the speed detection signals of the tachometer and the encoder and outputs to the third operational amplifier; the third operational amplifier compares and operates the speed detection signals with the control program speed given instruction signal to obtain a difference value, according to the difference value, outputs a speed adjustment instruction signal to the fourth operational amplifier; meanwhile, the second operational amplifier receives the oil pressure signals of the two pressure sensors on the output pipeline of the two electromagnetic reversing valves and outputs to the fourth operational amplifier; the fourth operational amplifier compares and operates the oil pressure signals of the pressure sensors with the speed adjustment instruction signal output by the third operational amplifier to obtain a pressure adjustment instruction signal and output to the two braking speed control circuits respectively.

[0017] Thirdly, the electric control device autonomously selects one of the two brake speed control circuits as the working circuit for speed control during the braking process, and the other as the standby circuit; the first operational amplifier of the electric control device receives speed detection signals from the speed detector and the encoder and outputs them to the third operational amplifier; the third operational amplifier compares and operates the speed detection signals with the speed given instruction signals from the control program to obtain a difference value, and outputs a speed adjustment instruction signal to the fourth operational amplifier according to the difference value; at the same time, the second operational amplifier receives oil pressure signals from two pressure sensors on the output pipe of the two electromagnetic directional control valves and outputs them to the fourth operational amplifier; the fourth operational amplifier compares and operates the oil pressure signals from the pressure sensors with the speed adjustment instruction signals output by the third operational amplifier to obtain a pressure adjustment instruction signal and output it to the working circuit.

[0018] Specifically, the control method of the parallel hot standby double-circuit speed control system of the hoist autonomously adjusts the speed change curvature according to different stages of the braking process and operating parameters; in the initial stage of braking, deceleration variable curvature control is implemented, and in the middle stage of braking, deceleration constant curvature control is implemented.

[0019] Specifically, the control method of the parallel hot standby double-circuit speed control system of the hoist autonomously adjusts the adjustment time of the speed change curvature according to different stages of the braking process and operating parameters; in the initial stage of braking, the adjustment time of the speed change curvature is automatically adjusted according to the size of the speed feedback signal of the speed measuring element, and the adjustment process of increasing the deceleration from zero to a constant value is as follows: the initial speed is large, and the adjustment time is increased; the initial speed is small, and the adjustment time is decreased.

[0020] A control method of a parallel hot standby double-circuit speed control system of a hoist, specifically:

[0021] Firstly, an external pressure oil source charges two accumulators through first and second check valves; the first and second accumulators output pressure oil through third and fourth check valves, the output ends of the third and fourth check valves are connected and then connected to a filter, and the outlet of the filter is divided into two paths to input pressure oil to first and second proportional directional control valves;

[0022] Secondly, the control program of the electric control device autonomously selects one of the two brake speed control circuits as the working circuit for speed control during the braking process, and the other as the standby circuit; the first operational amplifier of the electric control device receives speed detection signals from the speed detector and the encoder and outputs them to the third operational amplifier; the third operational amplifier compares and operates the speed detection signals with the speed given instruction signals from the control program to obtain a difference value, and outputs a speed adjustment instruction signal to the fourth operational amplifier according to the difference value; at the same time, the second operational amplifier receives oil pressure signals from two pressure sensors on the output pipe of the two electromagnetic directional control valves and outputs them to the fourth operational amplifier; the fourth operational amplifier compares and operates the oil pressure signals from the pressure sensors with the speed adjustment instruction signals output by the third operational amplifier to obtain a pressure adjustment instruction signal and output it to the working circuit;

[0023] Thirdly, the proportional reversing valve on the working circuit receives the pressure regulating instruction signal output by the fourth operational amplifier as a control instruction signal, and outputs pressure oil varying according to the control instruction signal, which is output to the electromagnetic reversing valve on the working circuit and then enters the brake, and the brake dynamically adjusts its brake force output value according to the received oil pressure value, thereby adjusting the hoist drum rotating speed.

[0024] Specifically, the control method of the parallel hot standby double-circuit speed control system of the hoist autonomously adjusts the speed change curvature according to different stages of the braking process and operating parameters, and the control program of the electrical control device adjusts the adjustment time of the speed change curvature in the initial stage of braking.

[0025] Specifically, the control method of the parallel hot standby double-circuit speed control system of the hoist autonomously adjusts the adjustment time of the speed change curvature according to different stages of the braking process and operating parameters, and the control program of the electrical control device adjusts the adjustment time of the speed change curvature in the initial stage of braking.

[0026] Due to the technical solutions described above, the present application has the following advantages:

[0027] The present application sets two braking speed control circuits, and sets a cutoff valve between the proportional reversing valve and the brake in each braking speed control circuit. When a fault occurs, the cutoff valve performs a power-off action to automatically cut off the circuit, physically isolates the fault circuit from the main circuit, and avoids affecting the normal working circuit of the braking system. The two braking speed control circuits can be switched and selected to work simultaneously or one to be used and one to be reserved by the electrical control device, and multiple working modes can be realized. The four one-way valves form a hydraulic bridge circuit, which can ensure that when any accumulator is damaged and loses pressure, the system automatically shields the faulty accumulator and works with another functional accumulator, realizes safe and stable braking, and ensures high reliability of the braking process. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a schematic diagram of the principle of the present application.

[0029] In the figure: 1 - hoist drum, 2 - brake, 3.1 - tachometer, 3.2 - encoder, 4.1-4.6 pressure sensor, 5.1 - first shutoff valve, 5.2 - second shutoff valve, 6.1 - first proportional directional valve, 6.2 - second proportional directional valve, 7.1 - first check valve, 7.2 - second check valve, 7.3 - third check valve, 7.4 - fourth check valve, 8.1 - first accumulator, 8.2 - second accumulator, 9.1 - first operational amplifier, 9.2 - second operational amplifier, 9.3 - third operational amplifier, 9.4 - fourth operational amplifier, 10.1-10.2 - electromagnetic directional valve, 11 - pressure regulating valve, 12 - filter. DETAILED DESCRIPTION

[0030] The application is further explained in conjunction with the accompanying drawings and examples, which cannot limit the protection scope of the application, and the purpose of disclosing the application is to protect all technical improvements within the scope of the application. Example 1

[0031] A hoist parallel hot standby dual-circuit speed control system, comprising a detection feedback device, a hydraulic system and an electrical control device;

[0032] The detection feedback device comprises a hoist drum 1, a speed measuring element and pressure sensors 4.1-4.6; the speed measuring element comprises a tachometer 3.1 and an encoder 3.2, and the tachometer 3.1 and the encoder 3.2 are respectively arranged on the speed measuring points at both ends of the hoist drum 1.

[0033] The hydraulic system comprises an accumulator, a one-way valve, a proportional directional valve, a cut-off valve, an electromagnetic directional valve, a pressure regulating valve 11 and a brake 2; the accumulator is provided in two, the pressure oil outlet of the first accumulator 8.1 is connected to the output end of the first one-way valve 7.1 and the input end of the third one-way valve 7.3 through a pipeline, and a pressure sensor 4.5 is arranged on the pipeline; the pressure oil outlet of the second accumulator 8.2 is connected to the output end of the second one-way valve 7.2 and the input end of the fourth one-way valve 7.4 through a pipeline, and a pressure sensor 4.6 is arranged on the pipeline; the four one-way valves form a hydraulic bridge, the input ends of the first one-way valve 7.1 and the second one-way valve 7.2 are connected through a pipeline and then connected to an external pressure oil source; the output ends of the third one-way valve 7.3 and the fourth one-way valve 7.4 are connected through a pipeline and then divided into two paths, and are respectively connected to the pressure oil input ends of the first proportional directional valve 6.1 and the second proportional directional valve 6.2; the output end of the first proportional directional valve 6.1 is connected to the input end of the first cut-off valve 5.1, and the output end of the second proportional directional valve 6.2 is connected to the input end of the second cut-off valve 5.2, and the first proportional directional valve 6.1 and the first cut-off valve 5.1, and the second proportional directional valve 6.2 and the second cut-off valve 5.2 form two parallel brake speed control circuits; the output ends of the first cut-off valve 5.1 and the second cut-off valve 5.2 are connected through a pipeline and then connected to the input ends of the electromagnetic directional valve 10.1 and the electromagnetic directional valve 10.2, and the output ends of the two cut-off valves and the input ends of the two electromagnetic directional valves are connected to the pressure regulating valve 11, and the pressure regulating valve 11 is used to limit the upper limit value of the pre-braking working oil pressure of the system; the output ends of the two electromagnetic directional valves are connected to the brake 2, and the pressure sensors 4.1 and 4.2 of the detection feedback device are arranged on the output end pipelines of the two electromagnetic directional valves; the brake 2 is arranged on the brake disc of the hoist drum 1.

[0034] The electrical control device comprises four operational amplifiers 9.1-9.4, a control program and a fault self-diagnosis algorithm; the two input ends of the first operational amplifier 9.1 are respectively connected to the tachometer 3.1 and the encoder 3.2; the output end of the first operational amplifier 9.1 is connected to one input end of the third operational amplifier 9.3, and the other input end of the third operational amplifier 9.3 receives a control program speed given instruction signal; the two input ends of the second operational amplifier 9.2 are respectively connected to the pressure sensors 4.1 and 4.2, and the output end of the second operational amplifier 9.2 and the output end of the third operational amplifier 9.3 are respectively connected to the two input ends of the fourth operational amplifier 9.4; the output end of the fourth operational amplifier 9.4 is respectively connected to the electrical control ports of the proportional directional valves 6.1 and 6.2; the control program and the fault self-diagnosis algorithm monitor, analyze and judge the detection feedback device and the hydraulic system during brake execution, and realize fault self-diagnosis.

[0035] Preferably, the test interface of the accumulator 8.1 is provided with a pressure sensor 4.3, and the pressure oil outlet pipeline is provided with a pressure sensor 4.5; the test interface of the accumulator 8.2 is provided with a pressure sensor 4.4, and the pressure oil outlet pipeline is provided with a pressure sensor 4.6; the pressure sensor on the test interface is used for monitoring the nitrogen pressure value and the charging time when the accumulator oil pressure is unloaded and charged, judging whether the accumulator bladder leaks, and giving a warning signal; the pressure sensor on the pressure oil outlet pipeline is used for testing the oil pressure.

[0036] Preferably, a filter 12 is arranged on the pipeline connected after the output ends of the third one-way valve 7.3 and the fourth one-way valve 7.4.

[0037] A control method of a hoist parallel hot standby double-circuit speed control system, in particular:

[0038] Firstly, the external pressure oil source charges the two accumulators through the first one-way valve 7.1 and the second one-way valve 7.2 respectively; the first accumulator 8.1 and the second accumulator 8.2 output pressure oil through the third one-way valve 7.3 and the fourth one-way valve 7.4 respectively; the third one-way valve 7.3 and the fourth one-way valve 7.4 are connected after the output ends and then connected to the filter 12; the filter 12 outlet is divided into two paths to input pressure oil to the first proportional directional valve 6.1 and the second proportional directional valve 6.2 respectively.

[0039] Secondly, the first operational amplifier 9.1 of the electrical control device receives the speed detection signals of the speed sensor 3.1 and the encoder 3.2 and outputs to the third operational amplifier 9.3; the third operational amplifier 9.3 compares and operates the speed detection signals with the control program speed given instruction signal to obtain a difference value, according to which, a speed adjustment instruction signal is output to the fourth operational amplifier 9.4; at the same time, the second operational amplifier 9.2 receives the oil pressure signals from the pressure sensor 4.1 and the pressure sensor 4.2 and outputs to the fourth operational amplifier 9.4; the fourth operational amplifier 9.4 compares and operates the oil pressure signals of the pressure sensor with the speed adjustment instruction signal output by the third operational amplifier 9.3 to obtain a pressure adjustment instruction signal and output to the two brake speed control circuits respectively.

[0040] Thirdly, the first proportional directional valve 6.1 and the second proportional directional valve 6.2 respectively receive the pressure adjustment instruction signals output by the fourth operational amplifier 9.4 as control instruction signals, and output pressure oil changed according to the control instruction signals respectively; the two brake speed control circuits simultaneously output pressure oil to the electromagnetic directional valve 10.1 and the electromagnetic directional valve 10.2 after entering the brake 2, and the brake 2 dynamically adjusts its brake force output value according to the received oil pressure value, thereby adjusting the rotating speed of the hoist drum 1.

[0041] Specifically, the control method of the hoist parallel hot standby double-circuit speed control system autonomously adjusts the speed change curvature according to different stages of the braking process and operating parameters; in the initial stage of braking, variable deceleration curvature control is implemented, and in the middle stage of the braking process, constant curvature control of the deceleration is implemented.

[0042] Specifically, the control method of the hoist parallel hot standby double-circuit speed control system autonomously adjusts the adjustment time of the speed change curvature according to different stages of the braking process and operating parameters; in the initial stage of braking, the adjustment time of the speed change curvature is automatically adjusted according to the size of the speed feedback signal of the speed measuring element, and the adjustment process of the deceleration from zero to a constant value is increased; the initial speed is small, and the adjustment time is reduced.

[0043] In this embodiment, if a braking speed control circuit fails, the system automatically cuts off the circuit, and the other circuit continues to complete the speed control of the braking process, realizing safe and stable braking; if both speed control circuits fail, the system monitors and judges the circuit failure, and the isolation valves 5.1 and 5.2 perform the power-off action to disconnect the faulty circuit and the brake 2, so as to physically isolate the faulty circuit from the main circuit and avoid affecting the normal working circuit of the braking system. Embodiment 2

[0044] The hoist parallel hot standby double-circuit speed control system of this embodiment is the same as that of embodiment 1.

[0045] A control method of a hoist parallel hot standby double-circuit speed control system, specifically:

[0046] First, the external pressure oil source charges the two accumulators through the first one-way valve 7.1 and the second one-way valve 7.2; the first accumulator 8.1 and the second accumulator 8.2 output pressure oil through the third one-way valve 7.3 and the fourth one-way valve 7.4, respectively, and the output ends of the third one-way valve 7.3 and the fourth one-way valve 7.4 are connected to the filter 12, and the filter 12 outlet is divided into two paths to input pressure oil to the first proportional directional valve 6.1 and the second proportional directional valve 6.2.

[0047] Secondly, the control program of the electric control device autonomously selects the brake speed control circuit in which the first proportional directional valve 6.1 is located as a working circuit to perform speed control in the braking process, and the brake speed control circuit in which the first proportional directional valve 6.2 is located as a standby circuit; the first operational amplifier 9.1 of the electric control device receives the speed detection signals of the tachometer 3.1 and the encoder 3.2 and outputs to the third operational amplifier 9.3; the third operational amplifier 9.3 compares and operates the speed detection signals with the speed given instruction signal of the control program to obtain a difference value, and according to the difference value, outputs a speed adjustment instruction signal to the fourth operational amplifier 9.4; at the same time, the second operational amplifier 9.2 receives the oil pressure signals from the pressure sensors 4.1 and 4.2 and outputs to the fourth operational amplifier 9.4; the fourth operational amplifier 9.4 compares and operates the oil pressure signals of the pressure sensors with the speed adjustment instruction signal output by the third operational amplifier 9.3 to obtain a pressure adjustment instruction signal and output to the working circuit;

[0048] Thirdly, the proportional directional valve 6.1 on the working circuit receives the pressure adjustment instruction signal output by the fourth operational amplifier 9.4 as a control instruction signal, and outputs pressure oil which changes according to the control instruction signal; the pressure oil on the working circuit enters the brake 2 after output by the electromagnetic directional valve, and the brake 2 dynamically adjusts the brake force output value according to the received oil pressure value, thereby adjusting the rotating speed of the hoist drum 1.

[0049] Specifically, the control method of the parallel hot standby double-circuit speed control system of the hoist adjusts the speed change curvature autonomously according to different stages and operating parameters in the braking process; in the initial stage of braking, the deceleration variable curvature control is implemented, and in the middle stage of the braking process, the deceleration constant curvature control is implemented.

[0050] Specifically, the control method of the parallel hot standby double-circuit speed control system of the hoist adjusts the adjustment time of the speed change curvature autonomously according to different stages and operating parameters in the braking process; in the initial stage of braking, the adjustment time of the speed change curvature is automatically adjusted according to the size of the speed feedback signal of the speed measuring element, and the adjustment process of increasing the deceleration from zero to a constant value; the initial speed is large, and the adjustment time is increased; the initial speed is small, and the adjustment time is reduced.

[0051] In the embodiment, if the working circuit fails, the system automatically cuts off the circuit, switches to the standby circuit to continue the speed control in the braking process, and realizes safe and stable braking.

[0052] The part not described in the present application is prior art.

[0053] The embodiments chosen for the purposes of disclosure herein are presently considered to be the most practical and preferred, it is to be understood that the application is intended to cover all changes and modifications in the embodiments that are within the scope of the concept and the application.

Claims

1. A parallel hot-standby dual-loop speed control system for a hoist, characterized in that, Includes detection feedback devices, hydraulic systems, and electrical control devices; The detection feedback device includes a hoist drum, a speed measuring element, and a pressure sensor; the speed measuring element includes a tachometer and an encoder, which are respectively installed at speed measuring points at both ends of the hoist drum. The hydraulic system includes an accumulator, check valves, proportional directional valves, isolation valves, solenoid directional valves, pressure regulating valves, and brakes. Two accumulators are configured. The pressure oil output port of the first accumulator is connected via pipeline to the output of the first check valve and the input of the third check valve, respectively. The pressure oil output port of the second accumulator is connected via pipeline to the output of the second check valve and the input of the fourth check valve, respectively. The four check valves form a hydraulic bridge circuit. The inputs of the first and second check valves are connected via pipelines to an external pressure oil source. The outputs of the third and fourth check valves are connected via pipelines and then split into two paths, which are respectively connected to the pressure oil input ports of the first and second proportional directional valves. The output port of the first proportional directional valve is connected to... The input port of the first isolation valve is connected, and the output port of the second proportional directional valve is connected to the input port of the second isolation valve. The first proportional directional valve and the first isolation valve, and the second proportional directional valve and the second isolation valve, respectively form two parallel braking speed control circuits. The output ports of the first isolation valve and the second isolation valve are connected to the input ports of two solenoid directional valves through pipelines. The output ports of the two isolation valves and the input ports of the two solenoid directional valves are both connected to pressure regulating valves. The pressure regulating valves are used to limit the upper limit of the pre-braking working oil pressure of the system. The output ports of the two solenoid directional valves are both connected to the brake. The two pressure sensors of the detection feedback device are respectively set on the output port pipelines of the two solenoid directional valves. The brake is set on the brake disc of the hoist drum. The electrical control device includes four operational amplifiers. The two inputs of the first operational amplifier are connected to a tachometer and an encoder, respectively. The output of the first operational amplifier is connected to one input of the third operational amplifier, and the other input of the third operational amplifier receives the speed command signal from the control program. The two inputs of the second operational amplifier are connected to two pressure sensors on the output pipes of two electromagnetic directional valves, respectively. The outputs of the second and third operational amplifiers are connected to the two inputs of the fourth operational amplifier, respectively. The output of the fourth operational amplifier is connected to the electrical control ports of two proportional directional valves, respectively.

2. The hoist parallel hot standby dual-loop speed control system according to claim 1, characterized in that: Pressure sensors are installed on the test interfaces and pressure oil output pipes of the two accumulators.

3. The hoist parallel hot standby dual-loop speed control system according to claim 1, characterized in that: A filter is installed on the pipeline connecting the output ends of the third and fourth check valves.

4. The hoist parallel hot standby dual-loop speed control system according to claim 1, characterized in that: The electrical control device includes a control program and a fault self-diagnosis algorithm. During the braking process, it monitors, analyzes, and judges the detection feedback device and the hydraulic system to achieve fault self-diagnosis.

5. A control method for a parallel hot-standby dual-loop speed control system for a hoist according to any one of claims 1-4, characterized in that, Specifically: First, an external pressure oil source charges the two accumulators with oil through the first check valve and the second check valve respectively; the first accumulator and the second accumulator output pressure oil through the third check valve and the fourth check valve respectively. The output ends of the third check valve and the fourth check valve are connected to the filter. The filter outlet is split into two paths to input pressure oil to the first proportional directional valve and the second proportional directional valve respectively. Secondly, the first operational amplifier of the electrical control device receives the speed detection signals from the tachometer and encoder and outputs them to the third operational amplifier; the third operational amplifier compares the speed detection signal with the speed command signal of the control program to obtain the difference, and outputs the speed adjustment command signal to the fourth operational amplifier based on this difference; at the same time, the second operational amplifier receives the oil pressure signals from the two pressure sensors on the output pipes of the two solenoid directional valves and outputs them to the fourth operational amplifier; the fourth operational amplifier compares the oil pressure signals from the pressure sensors with the speed adjustment command signal output by the third operational amplifier to obtain the pressure adjustment command signal and outputs it to the two braking speed control loops respectively; Secondly, the first proportional directional valve and the second proportional directional valve respectively receive the pressure regulation command signal output by the fourth operational amplifier as the control command signal, and respectively output pressure oil according to the change of the control command signal. The two braking speed control circuits simultaneously output pressure oil to the two solenoid directional valves and then enter the brake. The brake dynamically adjusts its braking force output value according to the received oil pressure value, thereby adjusting the speed of the hoist drum.

6. The control method of the hoist parallel hot standby dual-loop speed control system according to claim 5, characterized in that: The control method of the parallel hot standby dual-circuit speed control system for the hoist involves the electrical control device's control program autonomously adjusting the speed change curvature according to different stages of the braking process and operating parameters. In the initial stage of braking, deceleration variable curvature control is implemented, while in the intermediate stage of braking, deceleration constant curvature control is implemented.

7. The control method of the hoist parallel hot standby dual-loop speed control system according to claim 5, characterized in that: The control method of the parallel hot standby dual-circuit speed control system for the hoist involves the electrical control device's control program autonomously adjusting the adjustment time of the speed change curvature based on different stages of the braking process and operating parameters. In the initial braking stage, the adjustment time of the speed change curvature is automatically adjusted based on the magnitude of the speed feedback signal from the speed measuring element. During the adjustment process of the deceleration increasing from zero to a constant value, the adjustment time increases when the initial speed is large and decreases when the initial speed is small.

8. A control method for a hoist parallel hot standby dual-loop speed control system according to any one of claims 1-4, characterized in that, Specifically: First, an external pressure oil source charges the two accumulators with oil through the first check valve and the second check valve respectively; the first accumulator and the second accumulator output pressure oil through the third check valve and the fourth check valve respectively. The output ends of the third check valve and the fourth check valve are connected to the filter. The filter outlet is split into two paths to input pressure oil to the first proportional directional valve and the second proportional directional valve respectively. Secondly, the control program of the electrical control device autonomously selects one braking speed control loop as the working loop for speed control during the braking process, and the other as a backup loop; the first operational amplifier of the electrical control device receives the speed detection signals from the tachometer and encoder and outputs them to the third operational amplifier; the third operational amplifier compares the speed detection signal with the speed command signal given by the control program to calculate the difference, and outputs the speed adjustment command signal to the fourth operational amplifier based on this difference; at the same time, the second operational amplifier receives the oil pressure signals from the two pressure sensors on the output pipes of the two solenoid directional valves and outputs them to the fourth operational amplifier; the fourth operational amplifier compares the oil pressure signals from the pressure sensors with the speed adjustment command signal output by the third operational amplifier to calculate the pressure adjustment command signal and output it to the working loop; Secondly, the proportional directional valve in the working circuit receives the pressure regulation command signal output by the fourth operational amplifier as a control command signal, and outputs pressure oil according to the change of the control command signal. The pressure oil in the working circuit is output to the solenoid directional valve and then enters the brake. The brake dynamically adjusts its braking force output value according to the received oil pressure value, thereby regulating the speed of the hoist drum.

9. The control method of the hoist parallel hot standby dual-loop speed control system according to claim 8, characterized in that: The control method of the parallel hot standby dual-circuit speed control system for the hoist involves the electrical control device's control program autonomously adjusting the speed change curvature according to different stages of the braking process and operating parameters. In the initial stage of braking, deceleration variable curvature control is implemented, while in the intermediate stage of braking, deceleration constant curvature control is implemented.

10. The control method of the hoist parallel hot standby dual-loop speed control system according to claim 8, characterized in that: The control method of the parallel hot standby dual-circuit speed control system for the hoist involves the electrical control device's control program autonomously adjusting the adjustment time of the speed change curvature based on different stages of the braking process and operating parameters. In the initial braking stage, the adjustment time of the speed change curvature is automatically adjusted based on the magnitude of the speed feedback signal from the speed measuring element. During the adjustment process of the deceleration increasing from zero to a constant value, the adjustment time increases when the initial speed is large and decreases when the initial speed is small.

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