An elevator drive control system

Abstract

The application discloses an elevator car driving control system, and belongs to the elevator technical field. The driving control system comprises a driving motor speed detector for detecting the rotating speed of a driving motor of an elevator device, a driving motor current detector for detecting the current of the driving motor, a driving motor current controller for generating the expected torque of the driving motor according to the difference between the current instruction value and the current detection value of the driving motor, and a driving motor speed controller for generating the current instruction value of the driving motor according to the difference between the speed instruction value and the speed detection value of the driving motor, and further comprises a driving motor speed instruction generating unit for generating the speed instruction value of the driving motor according to the car speed instruction inputted from outside, the rotating detection value of the driving motor and the speed detection value of the elevator car. The technical scheme has the beneficial effects that the deformation amount of the flexible connecting body is included in the driving control cycle, and the driving control performance is improved.

Description

Technical Field

[0001] This invention relates to the field of elevator technology, and in particular to an elevator drive control system. Background Technology

[0002] In existing technologies, to stably control the speed of the elevator car and ensure passenger comfort and elevator operating efficiency, the elevator's drive motor is typically controlled. Traditional drive motor control utilizes a mathematical model of the drive motor and employs a dual-closed-loop variable voltage and variable frequency vector speed control technology to regulate its speed. This dual-closed-loop variable voltage and variable frequency speed control technology is based on the mathematical model of the drive motor itself. It adjusts the drive motor's operating speed based on feedback from the speed detection values, thereby regulating the elevator car's movement speed.

[0003] Taking traction elevator equipment as an example, the existing elevator structure is as follows: Figure 1 As shown, it includes an elevator car 11, a traction sheave 12, and a counterweight 13, with the upper end of the elevator car 11 and one side of the traction sheave 12 ( Figure 1 The left side of the traction sheave 12 is connected to the right side of the traction sheave 13 by a flexible connector (e.g., a steel wire rope) 14. Figure 1 The upper end of the counterweight device 13 and the right side of the elevator car 11 are connected by a flexible connector, and the lower end of the counterweight device 13 and the lower end of the elevator car 11 are connected by a compensating chain 15. If the elevator is a non-traction elevator, that is, an elevator controlled by a drive wheel, the main difference is that the counterweight device 13 is removed, that is, the drive wheel is directly connected to the lower end of the elevator car.

[0004] Whether it is a traction elevator or a non-traction elevator, in the traditional dual closed-loop variable frequency speed control technology, the motor rotor, drive wheel / traction wheel, flexible connector, and elevator car are regarded as a whole (hereinafter referred to as the transmission assembly). The transmission assembly is rigidly connected, that is, the deformation of the internal connection is ignored. Thus, the rotor angular velocity of the drive motor is directly converted into the moving speed of the elevator car, or conversely, the speed detection value of the drive motor is directly converted from the moving speed control command of the elevator car. On this basis, the speed detection value of the drive motor is used to realize the speed closed-loop control of the drive motor.

[0005] However, in actual operation, the internal connections of the aforementioned transmission assembly are not all rigid. A typical example is the flexible connection between the elevator car and the drive wheel / traction sheave. The flexible connection itself possesses a certain elastic damping effect. During elevator car operation, due to the tension generated by the elevator car and the drive wheel / traction sheave, the flexible connection will elongate, exhibiting dynamic deformation. This results in a significant time delay in the input and output signals passing through the flexible connection, leading to differences in both the time-domain and frequency-domain characteristics of the input and output signals. Therefore, if the aforementioned transmission assembly is treated as a rigidly connected whole for elevator car speed control, the dynamic characteristics of the flexible connection itself will be ignored, resulting in a reduction in drive control performance. Especially when the elastic modulus of the flexible connection is large, the elevator lifting height is large, and the elevator car position is low (in which case the length of the flexible connection between the elevator car and the drive wheel / traction sheave is long), the dynamic deformation of the flexible connection is relatively large, significantly impacting the elevator car speed control. From the passenger's perspective, this manifests as noticeable vertical vibration of the elevator car during movement.

[0006] In existing technologies, several technical solutions exist to address the problem of vertical vibration in elevator cars. A common approach is to detect the absolute position of the elevator car, using this position to determine its speed, and then employing this speed measurement for closed-loop speed control. However, the controlled object in this closed-loop speed control should be the entire system comprised of the elevator drive motor and the aforementioned transmission assembly. If, during speed control design, only the elevator drive motor is considered as the controlled object (i.e., only the elevator car's speed is considered), while ignoring the impact of the transmission assembly (mainly flexible connectors) on the overall speed control of the elevator, the control coupler performance of this closed-loop speed control will be reduced, and the vertical vibration during elevator operation will remain uneliminated.

[0007] To address the issue of vertical vibration during elevator car operation, Japanese Patent JP2004123256A discloses an elevator speed control device. This device calculates the elevator car's vibration frequency based on detected values, load, and signal components matching the calculated vibration frequency. After removing a pre-set speed command value, it outputs the final value and controls the drive motor speed accordingly. This published patent primarily employs a notch filter to remove the elevator car's vibration frequency components from the overall speed command value, thereby suppressing vertical vibration. However, this solution suffers from complex parameter calculations, making practical application difficult and costly.

[0008] Chinese patent CN112739637A discloses an elevator control device, which mainly suppresses elevator car vibration by superimposing a component that suppresses elevator car vibration frequency onto the speed command value. However, the implementation of this disclosed patent's technical solution is based on two fundamental assumptions: first, the transmission characteristic from the drive motor to the elevator car has a second-order delay factor; second, the attenuation coefficient of the rope between the elevator car and the sheave is 0. These two assumptions negatively impact the final speed regulation performance, thus causing the application of this technical solution to actually affect the elevator car's speed closed-loop control.

[0009] The published paper "Vertical-vibration control of elevator using estimated caracceleration feedback compensation" (IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, VOL.47, NO.1, FEBRUARY 2000, pp.91-99) proposes using an extended full-order observer to observe the acceleration of the elevator car, using a high-pass filter to filter the speed command of the drive motor to obtain the acceleration command value, and then using acceleration feedback control to suppress the vertical vibration of the elevator car. While this technical solution superficially solves the problem of vertical vibration of the elevator car, it does not fundamentally address the root causes of vertical vibration by analyzing the reasons for the vibration. Instead, it simply uses acceleration feedback for vibration control. Therefore, the actual control effect of this technical solution heavily depends on the accuracy of the observed car angular velocity, and its actual control effect is very limited.

[0010] In summary, the existing technical solutions for solving vertical vibration of elevator cars do not involve in-depth analysis of the causes of vertical vibration, nor do they eliminate the vibration at its root. They only address the superficial symptoms of vibration by feeding back, filtering, and adjusting the signals, resulting in unsatisfactory control effects. Summary of the Invention

[0011] Based on the above-mentioned technical problems, the present invention aims to provide a technical solution for an elevator drive control system, which designs a drive controller by taking the elevator car and the flexible connecting body connecting the elevator car as the controlled objects respectively, thereby including the dynamic deformation of the flexible connecting body into the closed-loop drive control cycle and improving the drive control performance of the elevator car.

[0012] The above technical solutions specifically include:

[0013] An elevator drive control system is applied to elevator equipment, the elevator equipment including an elevator car, a counterweight, a drive wheel, and a flexible connector connecting the elevator car and the counterweight and suspended on the drive wheel. The drive control system includes: a drive motor speed detector for detecting the rotational speed of the drive motor of the elevator equipment; a drive motor current detector for detecting the current of the drive motor; a drive motor current controller for generating a desired torque of the drive motor based on the difference between a current command value and a current detection value; and a drive motor speed controller for generating a current command value of the drive motor based on the difference between a speed command value and a speed detection value. The drive control system further includes:

[0014] Drive motor speed command generation unit: Generates the speed command value of the drive motor based on the externally input car speed command, the rotation detection value of the drive motor, and the speed detection value of the elevator car.

[0015] Preferably, the elevator drive control system further includes:

[0016] Compensation torque generation unit: Generates compensation torque based on the speed detection value of the drive motor, the speed detection value of the elevator car, and the mass of the flexible connector;

[0017] Compensation unit: At least the compensation torque output by the compensation torque generation unit is used to compensate the desired torque output by the drive motor current controller to obtain the final drive motor torque command.

[0018] Preferably, in this elevator drive control system, the compensation unit uses the sum of the compensation torque output by the compensation torque generation unit and the desired torque of the drive motor as the final drive motor torque command.

[0019] or

[0020] The compensation unit first calculates the sum of the compensation torque output by the compensation torque generation unit and the desired torque of the drive motor as a preliminary result. Then, it calculates the difference between the preliminary result and the torque generated by the counterweight device, and uses the obtained difference as the final torque command for the drive motor.

[0021] Preferably, in the elevator drive control system, the compensating torque generation unit further includes:

[0022] First force generation module: Generates a first force between the flexible connector and the elevator car based on the speed detection value of the drive motor and the speed detection value of the elevator car;

[0023] First calculation module: Calculates the gravity acting on the flexible connector based on the position of the elevator car and the linear density of the flexible connector;

[0024] The second calculation module calculates the sum of the gravity of the flexible connector and the first force as the first intermediate result, then calculates the product of the mass of the flexible connector and the equivalent acceleration of the flexible connector as the second intermediate result, and finally calculates and outputs the difference between the first intermediate result and the second intermediate result.

[0025] The third calculation module calculates the product of the output of the second calculation module and the radius of the drive wheel, and uses it as the compensation torque.

[0026] Preferably, in the elevator drive control system, the drive motor speed command generation unit further includes:

[0027] First force generation module: Generates a first force between the flexible connector and the elevator car based on the speed detection value of the drive motor and the speed detection value of the elevator car;

[0028] Car speed controller: Generates the command value of the first force based on the externally input speed command value of the elevator car and the speed detection value of the elevator car;

[0029] Flexible connector deformation controller: Generates the speed command value of the drive motor based on the command value of the first force and the first force output by the first force generation module.

[0030] Preferably, in the elevator drive control system, the first force generation module further includes:

[0031] Spring force calculation submodule: Calculates the spring force of the flexible connector based on the elongation deformation of the flexible connector;

[0032] Resistance calculation submodule: Calculates the resistance of the flexible connector based on the elongation deformation rate of the flexible connector;

[0033] Difference calculation submodule: used to output the difference between the spring force and the resistance as the first force.

[0034] Preferably, in the elevator drive control system, the first force generation module further includes:

[0035] Spring force calculation submodule: Calculates the spring force of the flexible connector based on the elongation deformation of the flexible connector;

[0036] Resistance calculation submodule: Calculates the resistance of the flexible connector based on the elongation deformation rate of the flexible connector;

[0037] Difference calculation submodule: used to output the difference between the spring force and the resistance as the first force.

[0038] Preferably, in this elevator drive control system, the spring force calculation submodule calculates the spring force of the flexible connector according to the following formula:

[0039]

[0040] in,

[0041] ΔL(x) represents the sum of the elongation deformation of the flexible connector from the drive wheel to the position x of the infinitesimal element dx on the flexible connector;

[0042] F 弹 Used to represent the spring force acting on the infinitesimal element dx on the flexible connector;

[0043] E represents the elastic modulus of the flexible connector;

[0044] ΔL(x) is calculated by the difference between the rotation detection value of the drive motor and the speed detection value of the elevator car.

[0045] Preferably, in this elevator drive control system, the resistance calculation submodule calculates the resistance of the flexible connector according to the following formula:

[0046]

[0047] in,

[0048] F 阻 Used to represent the resistance of the flexible connector;

[0049] ΔL is used to represent the sum of the elongation deformation of the flexible connector;

[0050] c represents the damping coefficient of the flexible connector.

[0051] Preferably, in this elevator drive control system, the controlled object of the flexible connector deformation controller is the flexible connector located between the drive wheel and the elevator car, and the mathematical model of the flexible connector is constructed as follows:

[0052]

[0053] in,

[0054] ΔL(x) represents the sum of the elongation deformation of the flexible connector from the drive wheel to the position x of the infinitesimal element dx on the flexible connector;

[0055] F 弹 Used to represent the spring force acting on the infinitesimal element dx on the flexible connector;

[0056] E represents the elastic modulus of the flexible connector;

[0057] ΔL(x) is calculated by the difference between the rotation detection value of the drive motor and the speed detection value of the elevator car;

[0058] F 阻 Used to represent the resistance of the flexible connector;

[0059] ΔL is used to represent the total elongation deformation of the flexible connector;

[0060] c represents the damping coefficient of the flexible connector;

[0061] F2 is used to represent the first force.

[0062] Preferably, in this elevator drive control system, the difference between the acceleration of the elevator car at the current moment and the linear acceleration of the drive wheel is used as the equivalent acceleration of the flexible connector at the next moment.

[0063] The beneficial effects of the above technical solution are as follows: by designing the drive control system with the elevator car and the flexible connecting body connecting the elevator car as the controlled objects respectively, the dynamic deformation of the flexible connecting body is included in the closed-loop drive control cycle, thereby improving the drive control performance of the elevator car. Attached Figure Description

[0064] Figure 1 This is a structural diagram of elevator equipment in the existing technology;

[0065] Figure 2 This is a schematic diagram of an elevator drive control system in a preferred embodiment of the present invention. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0068] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, but this is not intended to limit the scope of the invention.

[0069] Based on the problems existing in the prior art mentioned above, the technical solution of the present invention no longer regards the elevator car, flexible connector, drive wheel / traction wheel and motor rotor as an integral transmission assembly. Instead, the elevator car and flexible connector are designed as controlled objects to obtain the drive control command for the elevator car.

[0070] In a preferred embodiment of the present invention, an elevator drive control system is provided, which is applied to elevator equipment, such as... Figure 1 As shown, the elevator includes an elevator car 11 and a drive wheel (e.g., a traction wheel 12 in a traction elevator), a flexible connector 14 (e.g., a steel wire rope) is connected between the upper end of the elevator car 11 and the drive wheel, and a compensation chain 15 is connected between the lower end of the elevator car 11 and the drive wheel 12.

[0071] Then as Figure 2 As shown, the elevator drive control system includes a drive motor speed detector 21 for detecting the rotational speed of the drive motor of the elevator equipment, a drive motor current detector 22 for detecting the current of the drive motor, a drive motor current controller 23 for generating the desired torque of the drive motor based on the difference between the current command value and the current detection value of the drive motor, and a drive motor speed controller 24 for generating the current command value of the drive motor based on the difference between the speed command value and the speed detection value of the drive motor. The drive motor speed detector 21, drive motor current detector 22, drive motor current controller 23, and drive motor speed controller 24 are implemented using traditional voltage and current dual closed-loop variable frequency vector speed control technology, which will not be elaborated further here.

[0072] In this invention, the elevator drive control system further includes a drive motor speed command generation unit, which generates a drive motor speed command value based on the externally input car speed command, the rotation detection value of the drive motor, and the speed detection value of the elevator car.

[0073] Furthermore, such as Figure 2 As shown, the aforementioned drive motor speed command generation unit further includes:

[0074] First force generation module: Generates the first force between the flexible connector and the elevator car based on the speed detection values ​​of the drive motor and the elevator car;

[0075] Car speed controller 25: Generates the command value of the first force based on the externally input elevator car speed command value and the elevator car speed detection value;

[0076] Flexible connector deformation controller 26: Generates the speed command value of the drive motor based on the command value of the first force and the first force output by the first force generation module.

[0077] Specifically, a force analysis of the elevator car reveals that the force group acting on the elevator car during operation includes: the downward tension exerted on the elevator car by the gravity of the compensating chain 15 connected to the lower end of the elevator car due to its own mass; the downward gravity of the elevator car itself and the load inside the car; and the upward tension exerted on the elevator car by the lower end of the flexible connector. Therefore, the equation of motion for the elevator car should be:

[0078]

[0079] in:

[0080] m 厢 Used to indicate the total mass of the elevator car and the load inside the car;

[0081] m 链 Used to indicate the quality of the compensation chain;

[0082] g is the gravity coefficient;

[0083] F2 represents the downward pulling force exerted by the upper end of the elevator car on the flexible connector, which is the first force mentioned above.

[0084] v2 is used to represent the speed detection value of the elevator car, and then adopts... It can calculate the acceleration of the elevator car.

[0085] The weight of the elevator car itself and the weight of the load inside the car (m) 厢 The mass m of the aforementioned compensation chain can be obtained by using a weighing device installed on the car. 链 Since the value is fixed, as long as the real-time speed of the elevator car is obtained, the value of the first force between the elevator car and the flexible connector can be calculated. In this embodiment of the invention, the real-time speed of the elevator car can be detected by detecting the absolute position of the elevator car, which is the speed detection value of the elevator car mentioned above.

[0086] Accordingly, in the aforementioned car speed controller 25, the difference between the externally input given elevator car speed command and the elevator car speed detection value is input into the aforementioned formula (1), and the final output is the command value of the first force, that is, how to adjust it so that the actual operation of the elevator car matches the given speed command as closely as possible. In this invention, F is used. 2_ref The command value representing the first force.

[0087] The above tests measure the weight of the elevator car itself and the weight of the load inside the car, m. 厢 The above method of obtaining the speed detection value of the elevator car can be achieved using existing technology, and will not be elaborated further here.

[0088] In a preferred embodiment of the present invention, the first force generation module further includes:

[0089] Spring force calculation submodule 27: Calculates the spring force of the flexible connector based on the elongation deformation of the flexible connector;

[0090] Resistance calculation submodule 28: Calculates the resistance of the flexible connector based on the elongation deformation rate of the flexible connector;

[0091] Difference calculation submodule: used to output the difference between the spring force and the resistance as the first force.

[0092] Furthermore, as mentioned above, during elevator operation, the flexible connector between the elevator car and the drive wheel, when subjected to the tension forces of the elevator car and the drive wheel, can be equivalently represented as a combination of a spring and a damper. The spring effect manifests as an elongation deformation in the same direction as the external force when subjected to it, and this elongation deformation is related to the external tension force. The damping effect manifests as a resistance force generated when the flexible connector deforms, the magnitude of which is related to the speed of the elongation deformation. Therefore, the force analysis of the flexible connector should comprehensively consider both the spring deformation effect and the damping effect.

[0093] Furthermore, the flexible connector is affected by its own weight, and the effect of gravity varies at different points on the flexible connector. Specifically, the closer a point on the flexible connector is to the drive wheel, the greater the gravitational force it experiences due to the relatively longer length of the flexible connector beneath it, and thus the greater its elongation deformation. Conversely, the further away from the drive wheel, the greater the elongation deformation. Therefore, the analysis of the elongation deformation of the flexible connector cannot be simply regarded as a lumped parameter system, but rather as a distributed parameter system. The elongation deformation at each point on the flexible connector varies and is closely related to the external forces received at that point.

[0094] In this invention, regarding the spring effect of the flexible connector, the elongation deformation of the flexible connector is analyzed using the infinitesimal element method. For a certain infinitesimal element dx on the flexible connector, the resulting elongation deformation dL should be expressed as:

[0095]

[0096] in,

[0097] F is used to represent the external force exerted on a small element dx on a flexible connector;

[0098] E is used to represent the elastic modulus of a flexible connector;

[0099] dx is used to represent the length of the infinitesimal element.

[0100] Then as Figure 1 As shown, the elongation deformation produced by the flexible connection between the drive wheel and the infinitesimal element dx should be the sum of the elongation deformations of all infinitesimal elements dx. Therefore, the relationship between the elongation deformation produced by the flexible connection between the drive wheel and a certain infinitesimal element dx and the position x of that infinitesimal element dx can be expressed as:

[0101]

[0102] in,

[0103] ΔL(x) is used to represent the elongation deformation from the drive wheel to position x;

[0104] F 弹 That is, the external force F acting on the infinitesimal element dx on the flexible connector mentioned above can be considered as a spring force if the deformation rate of the infinitesimal element is not considered. Therefore, F is used here. 弹 express.

[0105] According to the above formula (3), if the elongation deformation of the flexible connector is known, the spring force F on the flexible connector can be directly calculated. 弹This means that the spring effect of the flexible connector can be quantified. The elongation deformation of the flexible connector can be represented by the difference between the travel distance of the elevator car and the rotation distance of the drive wheel. That is, the edge linear velocity of the drive wheel can be calculated by multiplying the rotation angle θ of the drive wheel and the radius R of the drive wheel, and then the difference between the drive wheel and the displacement velocity of the elevator car can be calculated to obtain the elongation deformation of the flexible connector. The rotation angle θ of the drive wheel can be obtained by a rotary encoder installed inside the drive wheel, and the displacement velocity of the elevator car can be obtained by detecting the absolute velocity of the elevator car as described above. Therefore, the elongation deformation of the flexible connector can be calculated by real-time detection, that is, the elongation deformation of the flexible connector is known. Then, according to the above formula (3), the spring force F on the flexible connector can be obtained. 弹 In other words, the spring force calculation submodule 27 described above can use the above formula (3) to calculate the spring force F generated on the flexible connector based on the known quantities. 弹 .

[0106] It is important to note that when the elevator is a traction elevator, the difference between the rotation angle of the traction sheave and the displacement velocity of the elevator car cannot be directly equated to the elongation deformation of the flexible connector. This difference must also include the slippage between the flexible connector and the traction sheave during the elevator car's movement. This slippage is inherent in traction elevator operation and cannot be eliminated, but it can be corrected for by the known distance between two fixed reference points in the elevator shaft, such as doors between adjacent floors or other fixed objects. The correction assumes the elevator car has already passed these two fixed objects, i.e., traveled the aforementioned known distance.

[0107] When the elevator equipment is a non-traction elevator, since the drive wheel control does not generate slippage, the elongation deformation of the flexible connector can be directly obtained by processing the difference between the rotation angle of the drive wheel and the displacement speed of the elevator car.

[0108] In this embodiment of the invention, considering that the slip amount has little effect on the overall elongation deformation of the flexible connector, in order to unify the calculation methods for traction elevators and non-traction elevators, the influence of slip amount is not considered here, and ΔL is directly used to represent the elongation deformation of the flexible connector. This ΔL is the sum of the elongation ΔL(x) corresponding to the infinitesimal element dx at each position on the flexible connector.

[0109] In this invention, regarding the damping effect of the flexible connector, as mentioned above, the damping force is related to the elongation deformation of the flexible connector. Therefore, the damping force of the flexible connector can be expressed by the following formula:

[0110]

[0111] in,

[0112] F 阻 Used to represent the damping force of a flexible connector;

[0113] c represents the damping coefficient of the flexible connector.

[0114] Based on the detection values ​​above, the elongation deformation of the flexible connector can be obtained, and the resistance of the flexible connector can be obtained according to formula (4), that is, the damping effect of the flexible connector is quantified.

[0115] Furthermore, the specific micro-element located at the connection point with the elevator car on the flexible connector experiences the elevator car, the load within the car, and the tensile force of the compensating chain, which is equal to the difference between the spring force and the damping force exerted on that specific micro-element by adjacent micro-elements. This is expressed as:

[0116] F2 = F 弹 -F 阻 (5)

[0117] The spring force F of the flexible connector is calculated in the spring force calculation submodule 26 and the resistance calculation submodule 27 respectively. 弹 and resistance F 阻 Then, the difference calculation submodule can calculate the first force F2 according to the above formula (5).

[0118] In a preferred embodiment of the present invention, the drive control system further includes:

[0119] Compensation torque generation unit 29: Generates compensation torque based on the speed detection value of the drive motor, the speed detection value of the elevator car, and the mass of the flexible connector;

[0120] Compensation unit 30: At least the compensation torque output by the compensation torque generation unit is used to compensate the desired torque of the drive motor to obtain the final drive motor torque command. This drive motor torque command is the final command value that acts on the drive motor of the elevator equipment and drives and controls the elevator equipment.

[0121] Furthermore, for non-traction elevators, the compensation unit 30 uses the sum of the compensation torque output by the compensation torque generation unit 29 and the desired torque of the drive motor as the final drive motor torque command.

[0122] For traction elevators, the influence of the torque generated by the counterweight needs to be considered. Therefore, the compensation unit 30 first calculates the sum of the compensation torque output by the compensation torque generation unit 29 and the desired torque of the drive motor as a preliminary result. Then, it calculates the difference between the preliminary result and the torque generated by the counterweight, and uses this difference as the final drive motor torque command. Specifically, a stress analysis is performed on the flexible connector itself:

[0123] For flexible connectors, the main forces involved are the downward tension F2 exerted by all components of the lower part of the elevator car (including the elevator car, load, and compensating chain) on the lower end of the flexible connector, the upward tension F1 exerted by the drive wheel on the upper end of the flexible connector, and the self-weight F of the flexible connector. 绳 The equation of motion for the flexible connector should be:

[0124] F2+F 绳 -F1=m 绳 ·a 绳 (6)

[0125] in,

[0126] m 绳 Used to indicate the mass of the flexible connector itself;

[0127] a 绳 Used to represent the equivalent acceleration of a flexible connector.

[0128] In the above formula (6):

[0129] F 绳 It is only related to the flexible connector itself, and its specific calculation is based on the following formula:

[0130] F 绳 =ρgl; (7)

[0131] ρ is the linear density of the flexible connector;

[0132] l represents the length of the flexible connector.

[0133] The equivalent acceleration a of the flexible connector 绳 It can be represented as:

[0134] a 绳 =a1+a2; (8)a1 is used to represent the acceleration of the flexible connector. This acceleration can be calculated based on the angular acceleration of the drive wheel, that is, by multiplying the angular acceleration of the drive wheel by the radius R of the drive wheel. This will not be elaborated here.

[0135] Regarding the above formula (7), although the flexible connector will elongate after being subjected to tension, and its linear density ρ will also decrease accordingly, this change is very slight and has little impact on the overall system. Therefore, in this invention, the change in linear density ρ is ignored and treated as a constant value.

[0136] The reason for not directly using the acceleration of the flexible connector to represent its equivalent acceleration is, as mentioned above, that during the actual operation of the elevator car, the forces acting on different positions of the flexible connector are different. This is mainly because the self-weight force acting on different positions of the flexible connector changes according to the length of the flexible connector below that position and the length of the compensation chain, thus affecting the deformation velocity and deformation acceleration of the flexible connector at different positions. Therefore, after considering the above factors, the concept of the deformation equivalent acceleration a2 of the flexible connector is introduced. The final equivalent acceleration a is obtained by correcting the acceleration a1 of the flexible connector calculated from the angular acceleration of the drive wheel using the deformation equivalent acceleration a2. 绳 The equivalent acceleration a2 of deformation can be calculated by the elongation deformation ΔL(x) on each infinitesimal element dx, that is, by differentiating the elongation deformation ΔL with respect to time, the equivalent acceleration a2 of deformation can be obtained.

[0137] Furthermore, in engineering practice, the deformation length of a flexible connector is generally small compared to its length in its natural state, and the acceleration caused by the dynamic characteristics of the flexible connector is not particularly significant along its length. Therefore, for some applications where the accuracy requirements for acceleration are not so high (e.g., the speed controller itself has a certain degree of robustness), the acceleration a1 of the flexible connector can be directly used as its equivalent acceleration a. 绳 The equivalent acceleration a is obtained without having to go through the calculation of the above formula (8).

[0138] Therefore, having already known the command value of the first force F2, F 绳 m 绳 and the equivalent acceleration a of the flexible connector 绳 Then, the command value of the upward pulling force F1 applied by the drive wheel to the upper end of the flexible connector can be calculated using the above formula (6).

[0139] Further force analysis of the drive wheel reveals that:

[0140] For traction elevators, the drive wheel is the traction sheave, which is mainly subjected to the torque T applied by the drive motor. e The torque T generated by the tension applied to the traction sheave by the upper end of the flexible connector on the elevator car side. 绳 (That is, the compensating torque) and the torque T generated by the tension applied to the traction sheave by the flexible connector on the counterweight side. 重 Since the dynamic characteristics of the flexible connection between the counterweight and the traction sheave have a relatively small impact on the speed control of the elevator car, the connection between the counterweight and the traction sheave is considered as a rigid connection in this application.

[0141] Taking the counterclockwise rotation of the traction sheave as the positive direction and the clockwise rotation as the negative direction, the motion equation of the traction sheave can be expressed as:

[0142]

[0143] Wherein, J is used to represent the equivalent moment of inertia of all components suspended on the traction sheave (including flexible connectors, counterweights, elevator cars, and compensating chains, etc.);

[0144] ω is the rotor angular velocity of the elevator's drive motor.

[0145] By transforming the above formula (9), we can obtain:

[0146]

[0147] In the above formula (10), F1 can be calculated using the above formula (6) to obtain the corresponding instruction value.

[0148] R is the radius of the traction sheave.

[0149] In this invention, when the rotor torque T of the drive motor is already known... e The commanded value of the tension F1, the radius R of the traction sheave, and the mass m of the elevator car and the load inside the car. 重 Then, the command value v1 of the edge linear velocity v1 of the traction sheave can be calculated according to the above formula (10). 1_ref That's it. It should be noted that the output of the aforementioned car speed controller 25 is the command value F for the first force. 2_ref This represents the difference between the actual first force and the expected first force as specified in the given car speed command. The command value v of the traction sheave's edge linear velocity is output here. 1_ref It is used to represent the desired value after adjusting and compensating for the real-time edge linear velocity.

[0150] For non-traction elevators, since they are driven by drive wheels and do not have a counterweight, T does not exist in the above formula (9). 重 The equivalent moment of inertia J also does not contain the influence of the counterweight device, and m is also absent in the above formula (10). 重 The calculation method for ·g·R is the same as that for traction elevators, and will not be repeated here.

[0151] Furthermore, when the drive wheel is a traction sheave, the torque T generated by the counterweight device needs to be considered. 重 The influence of the desired torque output by the drive motor current controller and the aforementioned compensation torque T 绳 After adding them, calculate the sum and the torque T. 重The difference between the values ​​is used as the final drive motor torque command to drive and control the elevator equipment using a dual closed-loop variable voltage and variable frequency speed regulation method.

[0152] When the drive wheel is a non-traction wheel, that is, a self-driven wheel, it is only necessary to combine the desired torque output by the drive motor current controller with the aforementioned compensation torque T. 绳 The sum can be used as the final drive motor torque command; the influence of the counterweight device does not need to be considered, meaning there is no need to calculate the torque T again. 重 .

[0153] In a preferred embodiment of the present invention, the compensation torque generation unit 29 further includes:

[0154] First force generation module: Generates the first force between the flexible connector and the elevator car based on the speed detection values ​​of the drive motor and the elevator car;

[0155] First calculation module: Calculates the gravity acting on the flexible connector based on the position of the elevator car and the linear density of the flexible connector;

[0156] The second calculation module calculates the sum of the gravity of the flexible connector and the first force as the first intermediate result, then calculates the product of the mass of the flexible connector and the equivalent acceleration of the flexible connector as the second intermediate result, and finally calculates and outputs the difference between the first intermediate result and the second intermediate result.

[0157] The third calculation module calculates the product of the output of the second calculation module and the radius of the drive wheel, and uses it as the compensation torque.

[0158] Specifically:

[0159] The operating principle of the first force generation module has been explained above and will not be repeated here.

[0160] The first calculation module calculates the gravity F acting on the flexible connector according to the above formula (7). 绳 .

[0161] The second calculation module calculates the tension F1 based on the above formula (6).

[0162] The third calculation module is based on formula T. 绳 =F1·R is achieved, and the compensation torque is finally obtained.

[0163] In a preferred embodiment of the present invention, the control object of the flexible connector deformation controller is the flexible connector located between the drive wheel and the elevator car. The mathematical model of the flexible connector is constructed according to the above formulas (3)-(5). Therefore, the flexible connector deformation controller 26 uses the flexible connector as the controlled object and calculates the command value v of the edge linear velocity of the drive wheel according to the above formulas (6)-(8) and (10). 1_ref .

[0164] In a preferred embodiment of the present invention, the difference between the acceleration of the elevator car at the current moment and the linear acceleration of the drive wheel is used as the equivalent acceleration of the flexible connector at the next moment.

[0165] Specifically, theoretically, the equivalent acceleration a of the flexible connector can be calculated using the above formula (8) and related descriptions. 绳 However, as mentioned above, the calculated value of a... 绳 First, the acceleration a1 and deformation acceleration a2 of the flexible connector need to be calculated. Calculating the deformation acceleration a2 requires calculating the overall elongation deformation ΔL of the flexible connector, which necessitates calculating the elongation deformation ΔL(x) of each infinitesimal element dx on the flexible connector. Considering the high computational complexity of this entire calculation process, in practice, to balance accuracy and processing efficiency, this embodiment directly uses the difference between the current elevator car's acceleration and the linear acceleration of the drive wheel as the equivalent acceleration of the flexible connector at the next moment. The elevator car's acceleration can be obtained by detecting the absolute position of the elevator car, and the drive wheel's linear acceleration can be obtained by the drive wheel's angular acceleration and radius. The drive wheel's angular acceleration can be detected by an encoder inside the drive wheel. These detection and calculation processes are the same as described above and will not be repeated here.

[0166] Of course, if we only consider the accuracy of the calculated values ​​and not the processing efficiency and the computing power of the system, we can calculate the equivalent acceleration of the flexible connector according to the above formula (8) and its related description, based on the theoretical design. That is, we can integrate the following formula and calculate the equivalent acceleration of the flexible connector:

[0167]

[0168] Here, ω represents the angular velocity of the drive wheel.

[0169] In summary, the technical solution of this invention, after analyzing the forces acting on the elevator car, drive wheel, and flexible connector in the elevator equipment, adds speed controllers specifically for the elevator car and flexible connector to the traditional voltage / current dual closed-loop variable frequency speed control system. Furthermore, it incorporates compensation torque for the drive wheel affected by the flexible connector and torque generated by the counterweight device. This addresses the root cause of the elevator car's vertical vibration problem, ensuring a comfortable ride for passengers while improving the elevator car's speed control performance and overall control efficiency.

[0170] The above description is merely a preferred embodiment of the present invention and does not limit the implementation and protection scope of the present invention. Those skilled in the art should realize that any equivalent substitutions and obvious changes made based on the description and illustrations of the present invention should be included within the protection scope of the present invention.

Claims

1. An elevator drive control system, applied to elevator equipment, the elevator equipment including an elevator car, a counterweight, a drive wheel, and a flexible connector connecting the elevator car and the counterweight and suspended on the drive wheel, the drive control system comprising: A drive motor speed detector for detecting the rotational speed of the drive motor of the elevator equipment, a drive motor current detector for detecting the current of the drive motor, a drive motor current controller for generating the desired torque of the drive motor based on the difference between the current command value and the current detection value of the drive motor, and a drive motor speed controller for generating the current command value of the drive motor based on the difference between the speed command value and the speed detection value of the drive motor; characterized in that the drive control system further includes: Drive motor speed command generation unit: Generates the speed command value of the drive motor based on the externally input car speed command, the rotation detection value of the drive motor, and the speed detection value of the elevator car; The drive control system further includes: Compensation torque generation unit: Generates compensation torque based on the speed detection value of the drive motor, the speed detection value of the elevator car, and the mass of the flexible connector; Compensation unit: at least uses the compensation torque output by the compensation torque generation unit to compensate the desired torque of the drive motor to obtain the final drive motor torque command; The compensation unit uses the sum of the compensation torque output by the compensation torque generation unit and the desired torque of the drive motor as the final drive motor torque command. or The compensation unit first calculates the sum of the compensation torque output by the compensation torque generation unit and the desired torque of the drive motor as a preliminary result. Then, it calculates the difference between the preliminary result and the torque generated by the counterweight device, and uses the obtained difference as the final torque command of the drive motor. The drive motor speed command generation unit further includes: First force generation module: Generates a first force between the flexible connector and the elevator car based on the speed detection value of the drive motor and the speed detection value of the elevator car; Car speed controller: Generates the command value of the first force based on the externally input speed command value of the elevator car and the speed detection value of the elevator car; Flexible connector deformation controller: Generates the speed command value of the drive motor based on the command value of the first force and the first force output by the first force generation module.

2. The elevator drive control system as described in claim 1, characterized in that, The drive motor speed command generation unit further includes: First force generation module: Generates a first force between the flexible connector and the elevator car based on the speed detection value of the drive motor and the speed detection value of the elevator car; Car speed controller: Generates the command value of the first force based on the externally input speed command value of the elevator car and the speed detection value of the elevator car; Flexible connector deformation controller: Generates the speed command value of the drive motor based on the command value of the first force and the first force output by the first force generation module.

3. The elevator drive control system as described in claim 2, characterized in that, The first force generation module further includes: Spring force calculation submodule: Calculates the spring force of the flexible connector based on the elongation deformation of the flexible connector; Resistance calculation submodule: Calculates the resistance of the flexible connector based on the elongation deformation rate of the flexible connector; Difference calculation submodule: used to output the difference between the spring force and the resistance as the first force.

4. The elevator drive control system as described in claim 3, characterized in that, The spring force calculation submodule calculates the spring force of the flexible connector according to the following formula: in, ΔL(x) represents the sum of the elongation deformation of the flexible connector from the drive wheel to the position x of the infinitesimal element dx on the flexible connector; F 弹 Used to represent the spring force acting on the infinitesimal element dx on the flexible connector; E represents the elastic modulus of the flexible connector; ΔL(x) is calculated by the difference between the rotation detection value of the drive motor and the speed detection value of the elevator car.

5. The elevator drive control system as described in claim 3, characterized in that, The resistance calculation submodule calculates the resistance of the flexible connector according to the following formula: in, F 阻 Used to represent the resistance of the flexible connector; ΔL is used to represent the sum of the elongation deformation of the flexible connector; c represents the damping coefficient of the flexible connector.

6. The elevator drive control system as described in claim 1, characterized in that, The flexible connector deformation controller controls the flexible connector located between the drive wheel and the elevator car. The mathematical model of the flexible connector is constructed as follows: in, ΔL(x) represents the sum of the elongation deformation of the flexible connector from the drive wheel to the position x of the infinitesimal element dx on the flexible connector; F 弹 Used to represent the spring force acting on the infinitesimal element dx on the flexible connector; E represents the elastic modulus of the flexible connector; ΔL(x) is calculated by the difference between the rotation detection value of the drive motor and the speed detection value of the elevator car; F 阻 Used to represent the resistance of the flexible connector; ΔL is used to represent the total elongation deformation of the flexible connector; c represents the damping coefficient of the flexible connector; F2 is used to represent the first force.

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