Control method and control device for hoisting equipment and hoisting equipment

Abstract

The application relates to the field of engineering machinery, and discloses a control method and a control device for hoisting equipment and the hoisting equipment. The hoisting equipment comprises a driving mechanism and an executing mechanism. The control method comprises the following steps: obtaining a preset position and an actual position of the executing mechanism; performing forward movement processing on the preset position to obtain an expected position; performing feedback control on the deviation between the expected position and the actual position to obtain a feedback frequency; and controlling the driving mechanism to work according to the feedback frequency to drive the executing mechanism to act. The scheme can reduce control errors.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery, and more specifically, to a control method, control device, and hoisting equipment for hoisting equipment. Background Technology

[0002] Lifting equipment (such as tower cranes) is one of the most commonly used lifting equipment on construction sites, used to move various building materials such as concrete, steel bars, formwork, and steel pipes. Currently, lifting equipment is mainly operated by drivers in a high-altitude cab on the tower, which requires a high level of skill and precision from the drivers, resulting in high labor costs and significant safety risks associated with working at height.

[0003] With the development of autonomous driving technology and in response to real-world needs, unmanned lifting equipment has emerged. This type of equipment can automatically plan paths and complete lifting operations, freeing up manual labor and addressing some current problems in lifting equipment construction. However, the automatic operation control technology for lifting equipment is one of the key technologies to be solved to achieve automated lifting operations with unmanned lifting equipment. Existing automatic operation control technologies for lifting equipment typically employ PID feedback control, which suffers from significant control errors due to the inherent inertia of lifting equipment. Summary of the Invention

[0004] The purpose of this invention is to provide a control method, control device, processor, and hoisting equipment for hoisting equipment, so as to solve the problem of large control errors in existing control methods for hoisting equipment.

[0005] To achieve the above objectives, a first aspect of the present invention provides a control method for hoisting equipment, the hoisting equipment including a drive mechanism and an actuator, the control method comprising:

[0006] Obtain the preset and actual positions of the actuator;

[0007] The preset position is shifted forward to obtain the desired position;

[0008] Feedback control is applied to the deviation between the desired position and the actual position to obtain the feedback frequency;

[0009] The operation of the drive mechanism is controlled based on the feedback frequency to drive the action of the actuator.

[0010] In this embodiment of the invention, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; shifting the preset position forward to obtain the desired position includes: removing the first preset number of position values ​​from the preset position sequence to obtain the desired position sequence.

[0011] In this embodiment of the invention, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; the preset position is shifted forward to obtain the desired position, which includes: selecting position values ​​from the preset position sequence at intervals of a second preset number to obtain the desired position sequence.

[0012] In this embodiment of the invention, the control method further includes: performing feedforward control on a preset position to obtain a feedforward frequency.

[0013] In this embodiment of the invention, feedforward control is performed on a preset position to obtain a feedforward frequency, including: calculating the feedforward velocity at the preset position to obtain the feedforward velocity; and determining the product of the feedforward velocity and a preset feedforward coefficient to obtain the feedforward frequency.

[0014] In this embodiment of the invention, controlling the operation of the drive mechanism according to the feedback frequency includes: controlling the operation of the drive mechanism according to the feedback frequency and the feedforward frequency.

[0015] In this embodiment of the invention, controlling the operation of the drive mechanism based on the feedback frequency and the feedforward frequency includes: controlling the operation of the drive mechanism based on the sum of the feedback frequency and the feedforward frequency.

[0016] In this embodiment of the invention, controlling the operation of the drive mechanism based on the sum of the feedback frequency and the feedforward frequency includes: controlling the operation of the drive mechanism based on the sum of the values ​​and a preset compensation value.

[0017] In this embodiment of the invention, the drive mechanism includes a positive dead zone value; controlling the operation of the drive mechanism according to the sum of the sum and the preset compensation value includes: when the hoisting equipment is in a stopped phase, determining the sum of the sum and the preset compensation value; when the sum of the sum and the preset compensation value is less than the positive dead zone value, controlling the operation of the drive mechanism according to the sum of the sum and the preset compensation value.

[0018] In this embodiment of the invention, the drive mechanism includes a negative dead zone value; controlling the operation of the drive mechanism according to the sum of the values ​​and a preset compensation value includes: when the hoisting equipment is in a stopped phase, determining the difference between the sum of the values ​​and the preset compensation value; when the difference between the sum of the values ​​and the preset compensation value is greater than the negative dead zone value, controlling the operation of the drive mechanism according to the difference between the sum of the values ​​and the preset compensation value.

[0019] In this embodiment of the invention, feedback control is performed on the deviation between the desired position and the actual position to obtain the feedback frequency, including: determining the feedback frequency based on the deviation, a preset proportional coefficient, a preset integral coefficient, and a preset differential coefficient.

[0020] In this embodiment of the invention, feedback control is performed on the deviation between the desired position and the actual position to obtain the feedback frequency, including: determining the product of the deviation and a preset proportional coefficient to obtain the feedback frequency.

[0021] A second aspect of the present invention provides a processor configured to execute the control method for hoisting equipment described above.

[0022] A third aspect of the present invention provides a control device for hoisting equipment, comprising: a position detection device for detecting the actual position of an actuator; and a processor according to the above.

[0023] A fourth aspect of the present invention provides a hoisting device, comprising: an actuator; a drive mechanism for driving the actuator to work; and a control device for the hoisting device according to the above.

[0024] The above technical solution obtains the preset position and actual position of the actuator, advances the preset position to obtain the desired position, and then performs feedback control on the deviation between the desired and actual positions to obtain the feedback frequency. Based on the feedback frequency, the drive mechanism is controlled to operate, thereby driving the actuator's movement. By advancing the preset position, this solution can issue effective control commands to the drive mechanism in advance, enabling accelerated or decelerated movements. This solves the problem of large control errors caused by the high inertia of hoisting equipment. Feedback control on the deviation between the desired and actual positions can adjust the position deviation and improve the position control accuracy of the actuator.

[0025] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used together with the following detailed description to explain the invention, but do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 The schematic diagram illustrates a flow chart of a control method for hoisting equipment according to an embodiment of the present invention;

[0028] Figure 2 This schematic diagram illustrates the control flow of a control method for hoisting equipment according to a specific embodiment of the present invention.

[0029] Figure 3 The diagram illustrates the structure of a control device for hoisting equipment according to an embodiment of the present invention. Detailed Implementation

[0030] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0031] Existing control methods mainly include three types: PID feedback control, feedforward control, and a combination of both. 1. PID feedback control calculates the error between the input and system feedback using the PID coefficients, and the result is directly output to the execution unit. This method is easy to implement in engineering, but its adjustment lags behind disturbances, resulting in unstable control output values ​​and making it unsuitable for nonlinear, high-inertia, and high-hysteresis control systems like those used for hoisting equipment. 2. Feedforward control uses the input to directly affect the output, making it an open-loop control method. Its advantages include fast response and no need to detect the system output, but it is prone to overcompensation or undercompensation, leading to significant errors. 3. The feedforward plus PID feedback control method combines the advantages of both, featuring fast response and small error. However, when applied to nonlinear, high-inertia, and high-hysteresis control systems like those used for hoisting equipment, it exhibits poor stability and large errors.

[0032] Lifting equipment is characterized by high inertia, slow response, large delay between the action of the lifting equipment and the command, and dead zone of the frequency converter. In addition, the hook and the body of the lifting equipment are flexibly connected by steel wire rope. Sudden acceleration, deceleration or turning will cause the hook to swing significantly. The swing is particularly obvious when controlling the slewing and luffing mechanisms. Large swing increases the safety risk of collision between the hoisted object and surrounding obstacles.

[0033] In traditional hoisting equipment operation, the operator sends commands to the frequency converter via a handle. The frequency converter then drives the three main mechanisms—slewing, luffing, and hoisting—to control the hook's movement. Therefore, in automatic operation, hoisting equipment only needs to send commands to the frequency converter to control these three mechanisms and achieve automatic hook control. Automatic operation of hoisting equipment mainly consists of three stages: starting, stable operation, and stopping. In the starting stage, the speed gradually increases from zero to a certain speed v. In the stable operation stage, the equipment operates at speed v. In the stopping stage, the speed gradually decreases from speed v to zero.

[0034] Figure 1 The illustration schematically shows a flowchart of a control method for hoisting equipment according to an embodiment of the present invention. Figure 1 As shown in the embodiment of the present invention, a control method for hoisting equipment is provided. Taking the application of this method to a processor of hoisting equipment as an example, the hoisting equipment includes a drive mechanism and an actuator. The control method may include the following steps:

[0035] Step S102: Obtain the preset position and actual position of the actuator.

[0036] It is understood that the preset position is the ideal position of the actuator set in advance. The actual position is the actual position of the actuator, which can be obtained through position detection equipment. The actuator may include, but is not limited to, a motor, a slewing mechanism, a luffing structure, a hoisting mechanism, and a hook, wherein the slewing mechanism, the luffing structure, and the hoisting mechanism can drive the hook to move through the hoisting rope.

[0037] Specifically, the processor can acquire the preset position and actual position of the actuator in real time or at preset time intervals.

[0038] Step S104: Move the preset position forward to obtain the desired position.

[0039] It can be understood that the desired position is the new position of the actuator after the preset position has been shifted forward.

[0040] Specifically, the processor can advance the preset position to obtain the desired position, which is earlier than the preset position. This allows the processor to issue effective control instructions for the drive mechanism earlier (the control instruction value is greater than the dead zone value of the drive mechanism), thereby further advancing the operation of the actuator.

[0041] In one embodiment, moving a preset position forward can be achieved by inputting the preset position to an acceleration / deceleration controller. It can be understood that the input to the acceleration / deceleration controller is the preset position, and the output is the desired position. The acceleration / deceleration controller can be a specific hardware device or a specific software algorithm.

[0042] Specifically, the processor inputs the preset position to the acceleration / deceleration controller, which processes the preset position and outputs the desired position, thus the processor obtains the desired position processed by the acceleration / deceleration controller.

[0043] Step S106: Feedback control is performed on the deviation between the desired position and the actual position to obtain the feedback frequency.

[0044] Specifically, after obtaining the desired position and the actual position, the processor can determine the deviation between the desired position and the actual position, and perform feedback control on the deviation to obtain the feedback frequency. The feedback control algorithm can be, for example, a PID control algorithm.

[0045] In one embodiment, feedback control of the deviation between the desired and actual positions can be achieved by inputting the deviation between the desired and actual positions to a feedback controller. It can be understood that the feedback controller is mainly used to adjust the position deviation; its input is the deviation value between the desired and actual positions, and its output is the feedback frequency. The feedback controller can be a specific hardware device or a specific software algorithm.

[0046] Specifically, after obtaining the desired position and the actual position, the processor can determine the deviation value between the desired position and the actual position, use the deviation value as the input of the feedback controller, and then obtain the feedback frequency output by the feedback controller.

[0047] Step S108: Control the drive mechanism to work according to the feedback frequency, so as to drive the actuator to move.

[0048] It is understood that the drive mechanism is used to receive instructions or data sent by the processor or controller, thereby driving the actuator to move. The drive mechanism may include, but is not limited to, a frequency converter.

[0049] Specifically, the processor can control the operation of the drive mechanism (e.g., frequency converter) based on the feedback frequency, thereby driving the actuator (e.g., rotary mechanism) to move.

[0050] The aforementioned control method for hoisting equipment obtains the preset and actual positions of the actuator, advances the preset position to obtain the desired position, and then performs feedback control on the deviation between the desired and actual positions to obtain the feedback frequency. Based on this feedback frequency, the drive mechanism is controlled to operate, thereby driving the actuator's movement. By advancing the preset position, this control method can issue effective control commands to the drive mechanism in advance, enabling earlier acceleration or deceleration. This addresses the problem of large control errors caused by the high inertia of hoisting equipment. Furthermore, the feedback control on the deviation between the desired and actual positions adjusts the positional deviation, improving the position control accuracy of the actuator.

[0051] In one embodiment, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; shifting the preset position forward to obtain the desired position includes: removing the first preset number of position values ​​from the preset position sequence to obtain the desired position sequence.

[0052] It can be understood that the preset position sequence is the position sequence of the trajectory planning or original planning, including multiple preset positions, such as [x(0), x(1)...x(n-1), x(n)], where the multiple preset positions can be arranged according to a certain time interval, such as 100ms. The desired position sequence is the sequence of multiple desired positions after being processed by the acceleration / deceleration controller, such as [x(N), x(N+1)...x(n-1), x(n)], where the multiple desired positions can also be arranged according to a certain time interval. The first preset quantity is the number of preset positions that need to be removed from the preset position sequence. The selection principle of the first preset quantity is to ensure that the actual position of the actuator (e.g., the hook) does not exceed the desired position, and to make the difference between the desired position and the actual position as large as possible, so as to issue effective control commands in advance.

[0053] Specifically, the processor can shift the preset position sequence (i.e., the position sequence of trajectory planning) such as [x(0), x(1)...x(n-1), x(n)] forward by a first preset number (e.g., N) of position data, that is, remove the position values ​​in the preset position sequence that are the first preset number (e.g., N) before x(N), that is, remove a segment of position values ​​before x(N), that is, the segment of position values ​​from x(0) to x(N-1), thereby obtaining the desired position sequence (i.e., the new position sequence) such as [x(N), x(N+1)...x(n-1), x(n)], and use this desired position sequence as an input to the feedback controller. Compared with the original planned position sequence, the position difference e(n) between it and the actual actuator becomes larger, and the control command value also becomes larger, thereby issuing an effective command in advance (the control command value is greater than the dead zone value of the drive mechanism), realizing early acceleration or deceleration, and solving the control problem caused by the large inertia of hoisting equipment. Furthermore, the selection principle of the first preset quantity (i.e., parameter N) is to ensure that the actual position (e.g., the actual turning position) does not exceed the position planned by the trajectory (e.g., the turning position), while making the position difference e(n) as large as possible, so as to issue effective control commands in advance.

[0054] In one embodiment, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; shifting the preset position forward to obtain the desired position includes: selecting position values ​​from the preset position sequence at intervals of a second preset number to obtain the desired position sequence.

[0055] It is understandable that the second preset quantity is the number of interval data selected in advance, such as 2 or 5.

[0056] Specifically, for the position sequence of trajectory planning, the processor can take a position value at intervals of a second preset number (e.g., M) of data to obtain the desired position sequence, which can increase the error e and achieve the purpose of issuing effective instructions in advance.

[0057] In one embodiment, the control method may further include: performing feedforward control on a preset position to obtain a feedforward frequency.

[0058] It's understandable that since the hook and the lifting equipment are flexibly connected by a wire rope, sudden acceleration, deceleration, or turning can cause significant swaying of the hook. Feedforward control ensures the smooth operation of the lifting equipment and avoids sudden acceleration, deceleration, or turning.

[0059] Specifically, the processor can perform feedforward control on a preset position to obtain the feedforward frequency.

[0060] In one embodiment, feedforward control is performed on a preset position to obtain a feedforward frequency, including: calculating the feedforward velocity at the preset position to obtain the feedforward velocity; and determining the product of the feedforward velocity and a preset feedforward coefficient to obtain the feedforward frequency.

[0061] Specifically, during the stable operation phase of hoisting equipment, the actuator runs at a certain speed v. To avoid sudden acceleration and deceleration, the processor calculates the feedforward average speed v(n) based on the preset position and with a preset time interval (e.g., 100ms). Then, v(n) is multiplied by the feedforward coefficient Kf to obtain the feedforward frequency q(n).

[0062] v(n) = (x(n) - x(nm)) / (m × 0.1)

[0063] q(n) = v(n) × Kf

[0064] Where x(n) and x(nm) are the preset positions of the actuator, m is the third preset quantity, which can be set in advance, and the feedforward coefficient Kf is obtained through experiments. That is, a definite control command C is sent to the actuator, the position is collected in real time at a fixed period T, and the speed V0 under this control command is calculated by the position and time T. Then Kf = C / V0.

[0065] In one embodiment, feedforward control of a preset position can be achieved by inputting the preset position to a speed feedforward controller. It is understood that the speed feedforward controller is used to ensure the smooth operation of hoisting equipment and avoid sudden acceleration, deceleration, or turning. The input to the speed feedforward controller is the preset position, and the output is the feedforward frequency. The speed feedforward controller can be a specific hardware device or a specific software algorithm.

[0066] Specifically, the processor inputs the preset position to the speed feedforward controller, which processes the preset position and outputs the feedforward frequency.

[0067] In one embodiment, controlling the operation of the drive mechanism according to the feedback frequency includes: controlling the operation of the drive mechanism according to the feedback frequency and the feedforward frequency.

[0068] Specifically, the processor can control the operation of the drive mechanism based on both the feedback frequency and the feedforward frequency, thereby driving the actuator to move.

[0069] In one embodiment, controlling the operation of the drive mechanism based on the feedback frequency and the feedforward frequency includes: controlling the operation of the drive mechanism based on the sum of the feedback frequency and the feedforward frequency.

[0070] Specifically, the processor can add the feedback frequency and the feedforward frequency together, and then control the drive mechanism to work based on the sum of the feedback frequency and the feedforward frequency, thereby driving the actuator to move.

[0071] In one embodiment, controlling the operation of the drive mechanism based on the sum of the feedback frequency and the feedforward frequency includes: controlling the operation of the drive mechanism based on the sum of the values ​​and a preset compensation value.

[0072] It is understandable that, due to the dead zone of the drive mechanism (e.g., frequency converter), the condition for hoisting equipment to finally stop moving is that the command value issued to the drive mechanism is less than the dead zone value of the drive mechanism. During the stopping phase of hoisting equipment (e.g., tower crane), feedback control plays a major role. Therefore, the condition for hoisting equipment to stop moving is that the feedback frequency is less than the dead zone value of the drive mechanism. The feedback frequency consists of the error and preset feedback control parameters. However, the error may not meet the expected final error (e.g., 0.05 degrees). Therefore, to improve control accuracy, a preset compensation value is set. Regarding the preset compensation value, a reasonable compensation value can be obtained through experiments, taking into account the situation during the start-up phase of the hoisting equipment. During the start-up phase, the speed of hoisting equipment is very small; an excessively large value will cause overcompensation, affecting the stability of the hoisting equipment control.

[0073] Specifically, the processor can control the drive mechanism to work based on the sum of the feedback frequency and the feedforward frequency, as well as a preset compensation value, thereby improving the final position control accuracy.

[0074] In one embodiment, controlling the drive mechanism based on the sum of the feedback frequency and the feedforward frequency plus a preset compensation value can be achieved as follows: The sum of the feedback frequency and the feedforward frequency plus the preset compensation value is input to a dead-zone compensator. The dead-zone compensator is used to reduce position errors; its inputs are the sum of the feedback frequency and the feedforward frequency plus the preset compensation value, and its output is the control command value for the drive mechanism. The dead-zone compensator can be a specific hardware device or a specific software algorithm.

[0075] In one embodiment, the drive mechanism includes a positive dead zone value; controlling the operation of the drive mechanism based on the sum of the sums and a preset compensation value includes: determining the sum of the sums and the preset compensation value when the hoisting equipment is in a stopped phase; and controlling the operation of the drive mechanism based on the sum of the sums and the preset compensation value when the sum of the sums and the preset compensation value is less than the positive dead zone value.

[0076] It is understandable that since the actuators of hoisting equipment (e.g., slewing, luffing, and lifting actuators) can move in the forward direction, the drive mechanism (frequency converter) has a forward dead zone. The position error can be reduced by setting a compensation value.

[0077] Specifically, during the stopping phase of hoisting equipment, the processor determines the sum of the feedforward frequency and the feedback frequency with the preset compensation value. That is, the sum of the feedforward frequency and the preset compensation value are calculated. Since the feedforward frequency is approximately 0 during this phase, the influence of the feedforward frequency can be temporarily ignored. When the sum of the feedforward frequency and the feedback frequency with the preset compensation value is less than the positive dead zone value, the drive mechanism can be controlled to work based on the sum of the feedforward frequency and the preset compensation value (which is approximately equal to the sum of the feedback frequency and the preset compensation value).

[0078] In one embodiment, the frequency converter includes a negative dead zone value; controlling the operation of the drive mechanism based on the sum of the values ​​and a preset compensation value includes: determining the difference between the sum of the values ​​and the preset compensation value when the hoisting equipment is in a stopped phase; and controlling the operation of the drive mechanism based on the difference between the sum of the values ​​and the preset compensation value when the difference between the sum of the values ​​and the preset compensation value is greater than the negative dead zone value.

[0079] It is understandable that since the actuators of hoisting equipment (e.g., slewing, luffing, and lifting actuators) can move in reverse, the drive mechanism (frequency converter) has a reverse dead zone. The position error can be reduced by setting a compensation value.

[0080] Specifically, during the stopping phase of hoisting equipment, the processor determines the difference between the sum of the feedforward frequency and the feedback frequency and the preset compensation value, that is, the sum is subtracted from the preset compensation value. Since the feedforward frequency is approximately 0 during this phase, the influence of the feedforward frequency can be temporarily ignored. When the difference between the sum of the feedforward frequency and the feedback frequency and the preset compensation value is greater than the negative dead zone value, the drive mechanism can be controlled to work based on the difference between the sum and the preset compensation value (which is approximately equal to the difference between the feedback frequency and the preset compensation value).

[0081] In one embodiment, feedback control is performed on the deviation between the desired position and the actual position to obtain the feedback frequency, including: determining the feedback frequency based on the deviation, a preset proportional coefficient, a preset integral coefficient, and a preset derivative coefficient.

[0082] Specifically, when the feedback control uses the PID control algorithm, the processor can determine the feedback frequency based on the deviation between the actual position and the desired position, as well as the pre-stored preset proportional coefficient, preset integral coefficient, and preset derivative coefficient.

[0083] In one embodiment, feedback control of the deviation between the desired position and the actual position includes: determining the product of the deviation and a preset proportional coefficient to obtain the feedback frequency.

[0084] Specifically, the processor can multiply the deviation between the desired position and the actual position by a preset scaling factor to obtain the feedback frequency.

[0085] Feedback control is illustrated using PID control as an example. PID coefficients include the proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd. Their specific values ​​can be obtained using the classic PID tuning method. To simplify PID coefficient tuning, we can set Ki = 0 and Kd = 0, and only need to adjust Kp. The PID calculation formula can be simplified as follows:

[0086] y(n) = Kp × e(n)

[0087] Furthermore, PID control (feedback control) mainly prevents overcompensation or undercompensation of speed feedforward control during the steady operation phase, and adjusts the position deviation in the later stage of the stopping phase to improve the final position control accuracy during the stopping phase.

[0088] Figure 2 The diagram illustrates a control flow chart of a control method for hoisting equipment according to a specific embodiment of the present invention. Figure 2 As shown, tower cranes are used as an example to illustrate hoisting equipment. A tower crane includes a drive mechanism (e.g., a frequency converter) and an actuator. The actuator comprises three main mechanisms: slewing, luffing, and hoisting. These three mechanisms drive the hook's movement via the hoisting rope. The hook's trajectory is planned in three stages: starting, stable operation, and stopping. The planned position sequence for the slewing, luffing, and hoisting mechanisms is an ideal position sequence with 100ms time intervals. The control methods for the slewing, luffing, and hoisting mechanisms are consistent; the technical solution will be explained using only the slewing mechanism as an example. Figure 2 As shown, the control method for hoisting equipment in this application includes four parts: an acceleration / deceleration controller, a speed feedforward controller, a PID position controller, and a frequency converter dead-zone compensator. The trajectory planning involves a slewing (and / or luffing and / or hoisting) position sequence (i.e.,... Figure 2In the input sequence, x(n) is used as the input of the acceleration / deceleration controller and the speed feedforward controller. After processing the input sequence, the acceleration / deceleration controller subtracts the actual slewing (and / or luffing and / or hoisting) position value of the hoisting equipment from its output to obtain the difference e(n). The PID position controller takes e(n) as input and performs PID calculation. Its output y(n) is added to the output q(n) of the speed feedforward controller to obtain the result u(n). The frequency converter dead zone compensator takes u(n) as input and obtains the final control command o(n) after compensation processing, which is output to the frequency converter.

[0089] During the start-up and stopping phases, the speed value is very small, the position error is also very small, and the control command value is also small. Because the frequency converter has a dead zone, the actuator will only execute the command and start to move when the control command value is greater than the dead zone value. In addition, the hoisting equipment itself has a large inertia and slow start-up and stopping actions, resulting in a large delay between the hoisting equipment's actions and the command, thus generating a large control error and even causing system instability.

[0090] To address this, this control method proposes an acceleration / deceleration controller that issues effective control commands in advance. The planned position sequence [x(0), x(1)…x(n-1), x(n)] is shifted forward by N position data points to obtain a new position sequence [x(N), x(N+1)…x(n-1), x(n)]. This sequence is used as an input to the PID position controller. Compared to the original planned position sequence, the difference e(n) between the actual position and the position of the actuator becomes larger, and the control command also increases accordingly, thus issuing effective commands in advance (the control command value is greater than the inverter dead zone value), achieving early acceleration and deceleration, and solving the control problem caused by the large inertia of hoisting equipment. The selection principle for parameter N is: to maximize the position difference e(n) while ensuring that the actual rotation position does not exceed the planned rotation position, thereby issuing effective control commands in advance.

[0091] The hook and the lifting equipment body are flexibly connected by a wire rope. Sudden acceleration, deceleration, or turning can cause the hook to swing significantly. During the stable operation phase of the lifting equipment, the main goal is to ensure its smooth operation and avoid sudden acceleration, deceleration, or turning. In this phase, the speed feedforward controller plays a key role.

[0092] During the stable operation phase, hoisting equipment operates at a certain speed v to avoid sudden acceleration and deceleration. The speed feedforward controller takes the position sequence of trajectory planning as input and calculates the feedforward average speed v(n) with a period of 100ms. Then, v(n) is multiplied by the feedforward coefficient Kf to obtain the output q(n) of the speed feedforward controller.

[0093] v(n) = (x(n) - x(nm)) / (m × 0.1)

[0094] q(n)=v(n)×Kf

[0095] wherein the feedforward coefficient Kf is measured through experiments: a determined control command C is sent to the actuator, the rotation position is collected in real time at a fixed period T, the speed V0 under this control command is calculated through the position and the time T, and Kf=C / V0.

[0096] The PID position controller takes the new position sequence output by the acceleration and deceleration controller and the actual position difference e(n) of rotation as input, and obtains the PID position control output y(n) through PID calculation.

[0097] Kp, Ki and Kd in the PID coefficients can be obtained by the classical adjustment method of PID. To simplify the adjustment of PID coefficients, set Ki=0 and Kd=0, and only Kp needs to be adjusted. The PID calculation formula is simplified as:

[0098] y(n)=Kp×e(n)

[0099] The PID position controller mainly prevents over-compensation or under-compensation of speed feedforward control during the stable operation stage, and adjusts the position deviation in the later period of the stop stage to improve the final position control accuracy in the stop stage.

[0100] Due to the dead zone of the frequency converter, the final condition for the hoisting equipment to stop moving is that the issued frequency converter command value is less than the dead zone value of the frequency converter. During the stopping stage of the hoisting equipment, the PID controller plays a major role. Therefore, the condition for the hoisting equipment to stop moving is Kp×e1<D, wherein e1 is the expected final error of rotation, and the current error e1=D / Kp, which may not meet the expected final error (e.g., 0.05 degrees). To improve the control accuracy, a frequency converter dead zone compensator is added. To satisfy the condition for the hoisting equipment to stop moving (the issued frequency converter command value is less than the dead zone value of the frequency converter), the compensation value C shall satisfy C+e1×Kp<D. The larger the C value, the smaller the error e1 value. Of course, the compensation value C shall be combined with the situation of the starting stage of the hoisting equipment, and a reasonable compensation value shall be obtained through tests. The speed of the hoisting equipment is very low during the starting stage, and an excessively large C value will cause over-compensation and affect the control stability of the hoisting equipment. Since the rotation, luffing and lifting actuators of the hoisting equipment can move forward and backward in both directions, the frequency converter has forward and reverse bidirectional dead zones. To compensate the forward and reverse bidirectional dead zones of the frequency converter, when the control command value is greater than e1×Kp, the compensation value C is added to the control command; when the control command value is less than -e1×Kp, the compensation value C is subtracted from the control command.

[0101] The control method for hoisting equipment described in this application has been tested and verified on hoisting equipment, showing that the trajectory tracking error (the difference between the planned position of the trajectory and the actual position of the hook of the hoisting equipment at the same moment) is small, for example, less than 0.8 meters, and the stability of the hook movement is better than that of manual operation. However, the test results of the feedforward plus feedback control method on hoisting equipment show that its error is large, for example, 5 meters, which is much larger than the error of this technical solution, and the stability is also poor.

[0102] In summary, the control method for hoisting equipment in this application includes four parts: an acceleration / deceleration controller, a speed feedforward controller, a PID position controller, and a frequency converter dead-zone compensator. The acceleration / deceleration controller issues effective commands in advance to achieve early acceleration or deceleration, solving the problem of large control errors caused by the high inertia of hoisting equipment. The speed feedforward controller ensures the smooth operation of the hoisting equipment, avoiding sudden acceleration, deceleration, or turning. The feedback controller prevents over-compensation or under-compensation in the speed feedforward control, adjusts position deviation, and improves position control accuracy. The frequency converter dead-zone compensator and the PID position controller work together to improve the final position control accuracy during the stopping phase. This technical solution solves the problem of smooth and precise control of large inertia and high hysteresis systems such as hoisting equipment (e.g., tower cranes), and has been verified on hoisting equipment, demonstrating advantages such as small errors and smooth control.

[0103] This invention provides a processor configured to: acquire a preset position and an actual position of an actuator; perform forward shifting processing on the preset position to obtain a desired position; perform feedback control on the deviation between the desired position and the actual position to obtain a feedback frequency; and control the drive mechanism to work according to the feedback frequency to drive the actuator to move.

[0104] This technical solution obtains the preset and actual positions of the actuator, advances the preset position to obtain the desired position, and then performs feedback control on the deviation between the desired and actual positions to obtain the feedback frequency. Based on the feedback frequency, the drive mechanism is controlled to operate, thereby driving the actuator's movement. This control method, by advancing the preset position, can issue effective control commands to the drive mechanism in advance, enabling accelerated or decelerated movements. This solves the problem of large control errors caused by the high inertia of hoisting equipment. Feedback control on the deviation between the desired and actual positions can adjust the position deviation and improve the position control accuracy of the actuator.

[0105] In one embodiment, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; the processor is further configured to remove the first preset number of position values ​​from the preset position sequence to obtain the desired position sequence.

[0106] In one embodiment, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; the processor is further configured to select position values ​​from the preset position sequence at intervals of a second preset number to obtain the desired position sequence.

[0107] In one embodiment, the processor is further configured to perform feedforward control on a preset position to obtain a feedforward frequency.

[0108] In one embodiment, the processor is further configured to: perform feedforward velocity calculation at a preset position to obtain a feedforward velocity; and determine the product of the feedforward velocity and a preset feedforward coefficient to obtain a feedforward frequency.

[0109] In one embodiment, the processor is further configured to control the operation of the drive mechanism based on the feedback frequency and the feedforward frequency.

[0110] In one embodiment, the processor is further configured to control the operation of the drive mechanism based on the sum of the feedback frequency and the feedforward frequency.

[0111] In one embodiment, the processor is further configured to control the operation of the drive mechanism based on the sum of the values ​​and a preset compensation value.

[0112] In one embodiment, the drive mechanism includes a positive dead zone value; the processor is further configured to: determine the sum of the summed value and a preset compensation value when the hoisting equipment is in a stopped phase; and control the drive mechanism to operate based on the sum of the summed value and the preset compensation value when the sum of the summed value and the preset compensation value is less than the positive dead zone value.

[0113] In one embodiment, the drive mechanism includes a negative dead zone value; the processor is further configured to: determine the difference between the summed value and a preset compensation value when the hoisting equipment is in a stopped phase; and control the drive mechanism to operate based on the difference between the summed value and the preset compensation value when the difference between the summed value and the preset compensation value is greater than the negative dead zone value.

[0114] In one embodiment, the processor is further configured to determine the feedback frequency based on the deviation, a preset proportional coefficient, a preset integral coefficient, and a preset derivative coefficient.

[0115] In one embodiment, the processor is further configured to determine the product of the deviation and a preset scaling factor to obtain the feedback frequency.

[0116] In one embodiment, such as Figure 2As shown, the processor may include four unit modules: an acceleration / deceleration controller, a speed feedforward controller, a PID position controller, and a frequency converter dead-time compensator. Furthermore, the acceleration / deceleration controller, speed feedforward controller, PID position controller, and frequency converter dead-time compensator may be implemented in hardware, software algorithms, or a combination of software algorithms and hardware.

[0117] Figure 3 The diagram schematically illustrates a structural block diagram of a control device for hoisting equipment according to an embodiment of the present invention. Figure 3 As shown, in this embodiment of the invention, a control device 300 for hoisting equipment is provided. The hoisting equipment includes a drive mechanism and an actuator. The control device 300 for hoisting equipment includes a position detection device 310 and a processor 320, wherein:

[0118] Position detection device 310 is used to detect the actual position of the actuator.

[0119] The processor 320 is configured to: acquire the preset position and the actual position of the actuator; perform forward processing on the preset position to obtain the desired position; perform feedback control on the deviation between the desired position and the actual position to obtain the feedback frequency; and control the drive mechanism to work according to the feedback frequency to drive the actuator to move.

[0120] The aforementioned control device 300 for hoisting equipment acquires the preset position and actual position of the actuator, advances the preset position to obtain the desired position, and then performs feedback control on the deviation between the desired and actual positions to obtain the feedback frequency. Based on the feedback frequency, it controls the drive mechanism to operate, thereby driving the actuator to move. By advancing the preset position, the control device can issue effective control commands to the drive mechanism in advance, enabling accelerated or decelerated movements. This solves the problem of large control errors caused by the high inertia of hoisting equipment. Feedback control on the deviation between the desired and actual positions adjusts the position deviation and improves the position control accuracy of the actuator.

[0121] In one embodiment, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; the processor 320 is further configured to remove the first preset number of position values ​​from the preset position sequence to obtain the desired position sequence.

[0122] In one embodiment, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; the processor 320 is further configured to: select position values ​​from the preset position sequence at second preset intervals to obtain the desired position sequence.

[0123] In one embodiment, the processor 320 is further configured to perform feedforward control on a preset position to obtain a feedforward frequency.

[0124] In one embodiment, the processor 320 is further configured to: perform feedforward velocity calculation at a preset position to obtain a feedforward velocity; and determine the product of the feedforward velocity and a preset feedforward coefficient to obtain a feedforward frequency.

[0125] In one embodiment, the processor 320 is further configured to control the operation of the drive mechanism based on the feedback frequency and the feedforward frequency.

[0126] In one embodiment, the processor 320 is further configured to control the operation of the drive mechanism based on the sum of the feedback frequency and the feedforward frequency.

[0127] In one embodiment, the processor 320 is further configured to control the operation of the drive mechanism based on the sum of the values ​​and a preset compensation value.

[0128] In one embodiment, the drive mechanism includes a positive dead zone value; the processor 320 is further configured to: determine the sum of the summed value and a preset compensation value when the hoisting equipment is in a stopped phase; and control the drive mechanism to operate based on the sum of the summed value and the preset compensation value when the sum of the summed value and the preset compensation value is less than the positive dead zone value.

[0129] In one embodiment, the drive mechanism includes a negative dead zone value; the processor 320 is further configured to: determine the difference between the summed value and a preset compensation value when the hoisting equipment is in a stopped phase; and control the drive mechanism to operate based on the difference between the summed value and the preset compensation value when the difference between the summed value and the preset compensation value is greater than the negative dead zone value.

[0130] In one embodiment, the processor 320 is further configured to determine the feedback frequency based on the deviation, a preset proportional coefficient, a preset integral coefficient, and a preset derivative coefficient.

[0131] In one embodiment, the processor 320 is further configured to determine the product of the deviation and a preset scaling factor to obtain the feedback frequency.

[0132] This invention provides a hoisting device, including: an actuator; a drive mechanism for driving the actuator to work; and a control device for the hoisting device as described in the above embodiments.

[0133] Therefore, this technical solution solves the problem of stable and precise control of large inertia and large hysteresis systems such as hoisting equipment, and has been verified on hoisting equipment, with advantages such as small error and stable control.

[0134] The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the specific details of the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0135] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0136] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A control method for hoisting equipment, the hoisting equipment comprising a drive mechanism, an actuator, and a feedback controller, characterized in that, The control method includes: Obtain the preset position and actual position of the actuator; The preset position is shifted forward to obtain the desired position; Feedback control is applied to the deviation between the desired position and the actual position to obtain the feedback frequency; The drive mechanism is controlled to operate according to the feedback frequency, so as to drive the actuator to move; Wherein, the preset position includes a preset position sequence, and the desired position includes a desired position sequence; the step of shifting the preset position forward to obtain the desired position includes: Remove the first preset number of position values ​​from the preset position sequence to obtain the desired position sequence; The step of feedback control of the deviation between the desired position and the actual position to obtain the feedback frequency includes: The input to the feedback controller is the deviation between the desired position and the actual position, and the output is the feedback frequency.

2. The control method according to claim 1, characterized in that, The preset position includes a preset position sequence, and the desired position includes a desired position sequence; the step of shifting the preset position forward to obtain the desired position includes: At every second preset interval, position values ​​are selected from the preset position sequence to obtain the desired position sequence.

3. The control method according to claim 1, characterized in that, The control method further includes: Feedforward control is applied to the preset position to obtain the feedforward frequency.

4. The control method according to claim 3, characterized in that, The step of performing feedforward control on the preset position to obtain the feedforward frequency includes: The feedforward velocity is calculated at the preset position to obtain the feedforward velocity; The product of the feedforward velocity and the preset feedforward coefficient is determined to obtain the feedforward frequency.

5. The control method according to claim 4, characterized in that, The step of controlling the operation of the drive mechanism according to the feedback frequency includes: The drive mechanism is controlled to operate based on the feedback frequency and the feedforward frequency.

6. The control method according to claim 5, characterized in that, The step of controlling the operation of the drive mechanism based on the feedback frequency and the feedforward frequency includes: The drive mechanism is controlled to operate based on the sum of the feedback frequency and the feedforward frequency.

7. The control method according to claim 6, characterized in that, The step of controlling the drive mechanism based on the sum of the feedback frequency and the feedforward frequency includes: The drive mechanism is controlled to operate based on the sum of the sums and the preset compensation value.

8. The control method according to claim 7, characterized in that, The drive mechanism includes a positive dead zone value; controlling the operation of the drive mechanism based on the summed value and a preset compensation value includes: When the hoisting equipment is in a stopped state, the sum of the added value and the preset compensation value is determined; If the sum of the summed value and the preset compensation value is less than the positive dead zone value, the drive mechanism is controlled to operate based on the sum of the summed value and the preset compensation value.

9. The control method according to claim 7, characterized in that, The drive mechanism includes a negative dead zone value; controlling the operation of the drive mechanism based on the summed value and a preset compensation value includes: When the hoisting equipment is in a stopped state, determine the difference between the summed value and the preset compensation value; If the difference between the summed value and the preset compensation value is greater than the negative dead zone value, the drive mechanism is controlled to operate based on the difference between the summed value and the preset compensation value.

10. The control method according to claim 1, characterized in that, The step of feedback control on the deviation between the desired position and the actual position to obtain the feedback frequency includes: The feedback frequency is determined based on the deviation, the preset proportional coefficient, the preset integral coefficient, and the preset differential coefficient.

11. The control method according to claim 1, characterized in that, The step of feedback control on the deviation between the desired position and the actual position to obtain the feedback frequency includes: The product of the deviation and the preset proportional coefficient is determined to obtain the feedback frequency.

12. A processor, characterized in that, Configured to perform a control method for hoisting equipment according to any one of claims 1 to 11.

13. A control device for hoisting equipment, characterized in that, include: A position detection device is used to detect the actual position of the actuator; as well as The processor according to claim 12.

14. A hoisting equipment, characterized in that, include: Executive agency; A drive mechanism is used to drive the actuator to move; as well as The control device for hoisting equipment according to claim 13.

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