Elevator control device

Abstract

The inertia and torque constants of an elevator are identified without requiring special operating conditions for the elevator, and the control gains used to control the hoisting machine are optimized. [Solution] The elevator control device comprises a speed control unit that calculates a current command value for the current flowing through the hoist so that the speed of the car traveling in the elevator shaft becomes the speed command value; a current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value; a torque constant identification unit that identifies the torque constant of the hoist using a current value including the actual current value or the current command value and the car load acting on the car; an inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car and the torque constant; and a gain update unit that updates the gain used in the calculations of the speed control unit using the inertia and the torque constant.

Description

[Technical Field]

[0001] The present disclosure relates to elevator control technology. [Background technology]

[0002] Patent Document 1 discloses a technology related to a servo device that controls the position and speed of a mechanical system including a servo motor. The servo device of this technology estimates the inertia term, viscosity term, Coulomb friction, steady disturbance force, and torque constant of the mechanical system, and changes the parameters of the control system based on the values ​​of the estimated parameters. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 11-65608 Summary of the Invention [Problem to be solved by the invention]

[0004] Estimation parameters such as inertia and torque constant are mutually related. Therefore, when considering accurately estimating each parameter in the technology described in Patent Document 1, different operating conditions are required to identify each parameter, which poses a problem of increasing the burden of parameter identification.

[0005] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a technology for identifying the inertia and torque constants of an elevator and optimizing the control gains used to control the hoisting machine, without requiring special operating conditions for the elevator. [Means for solving the problem]

[0006] The elevator control device disclosed herein includes a speed control unit that calculates a current command value for a current flowing through the hoist so that the speed of the car traveling in the elevator shaft becomes the speed command value; a current control unit that controls the hoist so that the actual current value flowing through the hoist becomes the current command value; a torque constant identification unit that identifies the torque constant of the hoist using a current value including the actual current value or the current command value and a car load acting on the car; an inertia identification unit that identifies the inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; and a gain update unit that updates a gain used in the calculations of the speed control unit using the inertia and the torque constant. [Effects of the Invention]

[0007] According to the technology of the present disclosure, it is possible to identify the inertia and torque constants of an elevator without requiring special operating conditions for the elevator, and to optimize the control gains used to control the hoisting machine. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a configuration diagram of an elevator according to a first embodiment. [Figure 2] FIG. 10 is a diagram for explaining elevator operation performed when torque constant identification processing and inertia identification processing are performed. [Figure 3] 3 is a flowchart showing a processing routine executed by the control device of the first embodiment. [Figure 4] FIG. 2 illustrates an example of hardware resources of a control device. [Figure 5] FIG. 10 is a diagram illustrating another example of hardware resources of a control device. [Figure 6] FIG. 1 is a diagram showing the relationship between car load W and inertia J. [Figure 7] 10 is a flowchart of a routine executed in a control device of a second embodiment. [Figure 8] 10 is a flowchart of a routine executed in a control device of a third embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment will be described with reference to the drawings. Note that elements common to the various drawings are given the same reference numerals and redundant explanations will be omitted.

[0010] Embodiment 1 1-1. Configuration of the elevator in the first embodiment FIG. 1 is a configuration diagram of an elevator according to a first embodiment. The elevator 100 according to the first embodiment is installed in a facility consisting of a building or the like having multiple floors. An elevator shaft for the elevator 100 is provided in the facility. The elevator shaft is a vertically long space spanning multiple floors.

[0011] The elevator 100 includes, as its main components, a hoisting machine 1, a rotation sensor 4, a main rope 5, a car 6, a counterweight 7, a weighing device 8, a current sensor 9, and a control device 10.

[0012] The hoisting machine 1 is installed, for example, at the top of a hoistway. The hoisting machine 1 includes an electric motor 3 and a sheave 2 attached to the shaft of the electric motor 3. The electric motor 3 is a power source that moves the car 6 up and down, and a permanent magnet synchronous motor, an induction motor, or the like is used.

[0013] The rotation sensor 4 is installed on the electric motor 3 and detects the rotation angle θ of the electric motor 3. The rotation sensor 4 is exemplified by, for example, an optical encoder or a resolver. The rotation angle θ of the electric motor 3 detected by the rotation sensor 4 is input to the control device 10 and used for speed control and current control of the electric motor 3.

[0014] A main rope 5 is wound around a sheave 2 of the hoisting machine 1. A car 6 is connected to one end of the main rope 5. A counterweight 7 is connected to the other end of the main rope 5. The car 6 and counterweight 7 are suspended in a bucket-like manner within the hoistway by the main rope 5. The car 6 and counterweight 7 move up and down within the hoistway by rotating the sheave 2 of the hoisting machine 1.

[0015] The weight of the counterweight 7 is adjusted based on the weight ratio of the car 6 to the rated capacity CP, called the "counter ratio γ." For example, when the counter ratio γ is set to 50%, the weight of the counterweight 7 is adjusted to a value obtained by adding the mass of the car 6 to the weight of 50% of the rated capacity CP.

[0016] The weighing device 8 detects the load acting on the car 6. The weighing device 8 may be attached to the car 6 or to the end of the main rope 5. There are no limitations on the installation position or type of the weighing device 8 as long as it can detect the load acting on the car 6. Also, although FIG. 1 illustrates an elevator with 1:1 roping, it may also be an elevator with 2:1 roping or other roping.

[0017] The current sensor 9 detects the current flowing through the electric motor 3. The current value detected by the current sensor 9 is the UVW phase current of the electric motor 3.

[0018] The control device 10 includes a speed detection unit 12, a speed control unit 14, a current control unit 16, a torque constant identification unit 18, an inertia identification unit 20, and a gain update unit 22 as functions realized by the processor executing a program.

[0019] The speed detection unit 12 is a functional block for calculating the rotation speed ω of the electric motor 3 from the rotation angle θ of the electric motor 3 detected by the rotation sensor 4. The rotation speed ω calculated by the speed detection unit 12 is sent to a speed control unit 14.

[0020] The speed control unit 14 is a functional block for determining a current command value I* by controlling the rotation speed of the electric motor 3. Typically, the speed control unit 14 is configured using, for example, PID control. The speed control unit 14 calculates the current command value I* so that the speed command value ω* matches the rotation speed ω calculated by the speed detection unit 12. The control gain of the speed control unit 14, for example, a PID control gain, is updated by a gain update unit 22, which will be described later.

[0021] The current control unit 16 is a functional block for calculating a voltage command value V* to be applied to the electric motor 3. Typically, the current control unit 16 is configured using, for example, PID control. The current control unit 16 calculates the voltage command value V* so that the actual current value I detected by the current sensor 9 follows the current command value I* calculated by the speed control unit 14.

[0022] Note that a dq-axis coordinate system is generally used for current control of the electric motor 3. In this case, the current command value I* output by the speed control unit 14 is a command value for the q-axis current, and the voltage command value V* output by the current control unit 16 is a command value for the q-axis voltage. The d-axis is not relevant to this disclosure and is therefore omitted from FIG. 1 . When the electric motor 3 is a permanent magnet synchronous motor, the command value for the d-axis current is set to 0. However, the command value for the d-axis current may not be set to 0 due to field weakening control or the like. When the electric motor 3 is an induction motor, a constant d-axis current is commanded as the excitation current. The d-axis voltage according to these d-axis current command values ​​is also converted into a phase voltage of the electric motor 3 together with the q-axis voltage and applied to the electric motor 3. The current value detected by the current sensor 9 is the UVW phase current of the electric motor 3. This is converted into a dq-axis current coordinate system using the rotation phase of the electric motor 3 detected by the rotation sensor 4 and used for current control by the current control unit 16.

[0023] The torque constant identification unit 18 is a functional block for identifying the torque constant Kt of the electric motor 3. Typically, the torque constant identification unit 18 identifies the torque constant Kt using the current command value I* calculated by the speed control unit 14, the rotation angle θ of the electric motor 3 detected by the rotation sensor 4, and the car load W of the car 6 detected by the weighing device 8. This processing is hereinafter referred to as "torque constant identification processing." Here, the torque constant is a proportional constant that indicates the relationship between the q-axis current value I of the electric motor 3 and the torque T, and has the relationship shown in the following equation (1). The relational expression between the torque command value T* and the current command value I* is given by the following equation (2) in which the q-axis current value I in equation (1) is replaced with the current command value I*. The torque constant identification processing will be described in detail later.

[0024] T = Kt × I (1) T*=Kt×I* (2)

[0025] The inertia identification unit 20 is a functional block for identifying the inertia J of the elevator. Here, the inertia J indicates the inertia of the entire system as seen from the electric motor 3. In other words, the inertia J is the inertia that should be controlled by the electric motor 3. The inertia identification unit 20 identifies the inertia J using the torque constant Kt identified in the torque constant identification unit 18, the current command value I* calculated by the speed control unit 14, and the rotation angle θ of the electric motor 3 detected by the rotation sensor 4. This processing will be referred to as "inertia identification processing" hereinafter. The inertia identification processing will be described in detail later.

[0026] The gain update unit 22 is a functional block for updating the gain of the speed control unit 14. Typically, the gain update unit 22 calculates and updates the gain of the speed control unit 14 using the torque constant Kt identified in the torque constant identification unit 18, the inertia J identified in the inertia identification unit 20, and the car load W of the car 6 detected by the weighing device 8. This processing is hereinafter referred to as "gain update processing." The gain update processing will be described in detail later.

[0027] 1-2. Overview of torque constant identification process Next, an overview of the torque constant identification process performed by the torque constant identification unit 18 will be described. In the following description, the range from the vertical center position of the elevator shaft to the top floor will be referred to as the "upper region," and the range from the middle position to the bottom floor will be referred to as the "lower region." When the elevator is operating upward, the torque Tua acting on the motor 3 while accelerating in the lower region is expressed by the following equation (3).

[0028] Tua = Ju × aua + Uc - Ur - L (3)

[0029] In equation (3), Ju represents the inertia of the elevator during ascending operation, aua represents the acceleration of the elevator during ascending operation, Uc represents the torque acting on the motor 3 due to the weight difference between the car 6 and the counterweight 7, Ur represents the torque acting on the motor 3 due to the rope weight difference between the weight of the main rope 5 between the car 6 and the sheave 2 and the weight of the main rope 5 between the counterweight 7 and the sheave 2, and L represents the torque due to the elevator's running loss. Hereinafter, inertia Ju will also be referred to as the "first inertia identification value." Note that the sign of Uc changes depending on the load on the car 6. For example, if the counter rate is 50%, when the load on the car 6 exceeds 50% of the rated capacity, the weight of the car 6 becomes greater than the weight of the counterweight 7, and the sign changes. Furthermore, the sign of Ur changes depending on the position of the car 6. For example, when the car 6 is located in the lower region, the main rope 5 on the car 6 side is longer than the main rope 5 on the counterweight 7 side, but when the car 6 is located in the upper region, the main rope 5 on the counterweight 7 side is longer than the main rope 5 on the car 6 side. Therefore, when the car 6 moves from the lower region to the upper region across the middle position of the hoistway, the sign of Ur changes.

[0030] During an upward movement, when the elevator is traveling at a constant speed and is not accelerating or decelerating, the torque Tum acting on the motor 3 is expressed by the following equation (4), which ignores the acceleration term from equation (3).

[0031] Tum=Uc-Ur-L (4)

[0032] In the ascending operation of the elevator, the torque Tud acting on the motor 3 while decelerating in the upper region is expressed by the following equation (5).

[0033] Tud = Ju × aud + Uc + Ur-L (5)

[0034] In equation (5), aud represents the deceleration during ascending operation. Note that in equation (5), the sign of the torque Ur due to the rope weight difference changes compared to equation (3). This is because car 6 is moving from the lower region to the upper region across the middle of the hoistway.

[0035] Next, in the descending operation of the elevator, the torque Tda acting on the motor 3 while accelerating in the upper region is expressed by the following equation (6).

[0036] Tda = Jd × ada + Uc + Ur + L (6)

[0037] In equation (6), Jd represents the inertia of the elevator during descent, and ada represents the acceleration of the elevator during descent. The inertia Jd is hereinafter also referred to as the "second inertia identification value."

[0038] When the elevator is traveling at a constant speed and not accelerating or decelerating while it is descending, the torque Tdm acting on the motor 3 is expressed by the following equation (7), which ignores the acceleration term from equation (6).

[0039] Tdm = Uc + Ur + L (7)

[0040] When the elevator is in a descending operation, the torque Tdd acting on the motor 3 while decelerating in the lower region is expressed by the following equation (8): In equation (8), add indicates the deceleration of the elevator during the descending operation.

[0041] Tdd = Jd × add + Uc - Ur + L (8)

[0042] Here, when the car 6 is located at the midpoint, which is the reference position for the elevator's ascent and descent stroke, the weight of the main rope 5 on the car 6 side is equal to the weight of the main rope 5 on the counterweight 7 side, so the torque Ur generated by the difference in weight of the main rope 5 can be considered to be zero. Also, the torque L due to running loss during ascending operation can be considered to be the same magnitude as the torque L due to running loss during descending operation. Therefore, when equations (4) and (7) are added together, the torque L due to running loss cancels out, resulting in the following equation (9).

[0043] Tum+Tdm=2Uc (9)

[0044] The relationship between torque T and current value I is expressed as T = Kt × I, so the torque Tum when traveling at the middle position of the ascending / descending stroke during ascending operation and the torque Tdm when traveling at the middle position of the ascending / descending stroke during descending operation are expressed by the following equations (9) and (10).

[0045] Tum = Kt × Ium (9) Tdm = Kt × Idm (10)

[0046] Here, the current values ​​Ium and Idm can be the current command value I* calculated by the speed control unit 14 when the car travels at a constant speed at an intermediate position in the ascending or descending stroke during ascending or descending operation. Alternatively, the current values ​​Ium and Idm can be the current value I detected by the current sensor 9 when the car travels at a constant speed at an intermediate position in the ascending or descending stroke during ascending or descending operation. The position of the car 6 in the hoistway can be detected, for example, using the rotation angle θ detected by the rotation sensor 4 of the motor 3. Note that the means for detecting the position of the car 6 in the hoistway is not limited to the above, and any configuration that can detect the position of the car 6 in the hoistway can be used. From equations (9) and (10), the torque constant Kt can be calculated using the following equation (11).

[0047] Kt = 2Uc / (Ium + Idm) (11)

[0048] When no load is acting on the car 6, the torque Uc due to the weight difference between the car 6 and the counterweight 7 can be calculated by the following equation (12) using the rated capacity CP of the car 6, the counter rate γ, the radius r of the sheave 2, and the gravitational acceleration g. Also, when a load W is acting on the car 6, the torque Uc can be calculated by the following equation (13) using the car load W detected by the weighing device 8.

[0049] Uc = CP × γ × g × r (12) Uc=(CP×γ+W)×g×r (13)

[0050] As described above, the torque constant identification unit 18 can identify the torque constant Kt by substituting the torque Uc calculated using equation (12) or (13) and the current values ​​Ium and Idm obtained when traveling at a constant speed at the middle position of the ascending or descending stroke into equation (11).

[0051] 1-3.Outline of inertia identification process Next, an overview of the inertia identification process performed by the inertia identification unit 20 will be described. If the torque Ur due to the rope weight difference at the first position P1 in the lower region is defined as Ur1 and the torque Ur due to the rope weight difference at the second position P2 in the upper region is defined as Ur2, then the torque Tua during acceleration at the first position P1 in the ascending / descending stroke and the torque Tud during deceleration at the second position P2 in the ascending / descending stroke during the elevator's upward operation are obtained from equations (3) and (5) as the following equations (14) and (15). Note that in equations (14) and (15), the acceleration aua is also called the "first acceleration" and the deceleration aud is also called the "second deceleration."

[0052] Tua=Ju×aua+Uc-Ur1-L ···(14) Tud=Ju×aud+Uc+Ur2-L ···(15)

[0053] If there is no change in the number of occupants in the car 6 at the first position P1 and the second position P2, the torque Uc due to the weight difference between the car 6 and the counterweight 7 can be considered to be the same value at the first position P1 and the second position P2. Also, if the torque L due to the running loss is assumed to be the same value at the first position P1 and the second position P2, the first inertia identification value Ju is given by the following equation (16) from equations (14) and (15).

[0054] Ju=(Tua-Tud+Ur1+Ur2) / (aua-aud) ···(16)

[0055] Similarly, if the torque Ur due to the rope weight difference at the third position P3 in the upper region is defined as Ur3, and the torque Ur due to the rope weight difference at the fourth position P4 in the lower region is defined as Ur4, then the torque Tda during acceleration at the third position P3 and the torque Tdd during deceleration at the fourth position P4 during the elevator's downward operation are obtained from equations (6) and (8) as the following equations (17) and (18). Note that in equations (17) and (18), the acceleration ada is also called the "third acceleration," and the deceleration add is also called the "fourth deceleration."

[0056] Tda=Jd×ada+Uc+Ur3+L ···(17) Tdd=Jd×add+Uc-Ur4+L ···(18)

[0057] Here, if the first position P1 and the fourth position P4, and the second position P2 and the third position P3 are the same position, Ur1 and Ur4, and Ur2 and Ur3 will have the same value, respectively. Therefore, from equations (17) and (18), the second inertia identification value Jd is given by the following equation (19).

[0058] Jd=(Tda-Tdd-Ur1-Ur2) / (ada-add) ···(19)

[0059] Here, when the elevator is operated so that the first acceleration aua during ascending operation is equal to the third acceleration ada during descending operation, and the second deceleration aud during ascending operation is equal to the fourth deceleration add during descending operation, the sum of the first inertia identification value Ju and the second inertia identification value Jd is expressed by the following equation (20).

[0060] Ju+Jd=((Tua-Tud)+(Tda-Tdd)) / (aua-aud) ···(20)

[0061] If the average value of the first inertia identified value Ju and the second inertia identified value Jd is taken as the final identified value of inertia J and each torque value in equation (20) is replaced with a current value, the following equation (21) is obtained. Note that in equation (21), the current values ​​Iua, Iud, Ida, and Idd are also referred to as the "first current value," "second current value," "third current value," and "fourth current value," respectively.

[0062] J=(Ju+Jd) / 2=Kt((Iua-Iud)+(Ida-Idd)) / (aua-aud) / 2 ···(21)

[0063] As described above, the inertia identification unit 20 can identify the inertia J by substituting the torque constant Kt identified by the torque constant identification unit 18 and the current values ​​Iua, Iud, Ida, and Idd obtained during specific operation using the acceleration / deceleration rates aua and aud described above into equation (21).

[0064] 1-4. Gain update process overview A gain update unit 22 updates the gain used in the speed control unit 14 by using the torque constant Kt identified in the torque constant identification unit 18 and the inertia J identified in the inertia identification unit 20. The speed control of the electric motor 3 by the speed control unit 14 is implemented by, for example, PI control. In this case, the P gain KP and the I gain KI are designed as shown in the following equations (22) and (23).

[0065] KP = ωc×J / Kt (22) KI = KP×ωc / 5 (23)

[0066] In equations (22) and (23), ωc is the control band of the speed control unit 14. As shown in equations (22) and (23), the PI gain of the speed control unit 14 is determined by the inertia J and the torque constant Kt. If the inertia and torque constant set in the speed control unit 14 differ from their actual values, there is a risk of problems such as the occurrence of control errors and oscillations in the control system. Therefore, stable control can be achieved by optimizing the gain of the speed control unit 14 using the identified torque constant Kt and inertia J. Note that the speed control by the speed control unit 14 is not limited to PI control, and various control methods such as PID control or two-degree-of-freedom control can be used. The identified inertia J and torque constant Kt can also be used to update the gains of such other control methods.

[0067] 1-5. Specific processing executed by the control device in the first embodiment Fig. 2 is a diagram for explaining elevator operation that is executed when torque constant identification processing and inertia identification processing are performed. Fig. 3 is a flowchart showing a processing routine that is executed by the control device of embodiment 1. Specific processing that is executed by the control device will be described below with reference to Fig. 2 as well.

[0068] In step S100, the elevator starts ascending. The ascending operation includes acceleration operation, constant speed operation, and deceleration operation. A jerk is typically provided to improve the elevator's ride comfort, and it takes several seconds for the acceleration to reach a constant value. During the upward acceleration operation, the motor 3 continues accelerating at the first acceleration aua after reaching a constant first acceleration aua until it reaches a rated speed. Once the rated speed is reached, the ascending operation transitions to constant speed operation. During the constant speed operation, the motor 3 continues operating at the rated speed. Then, as the elevator approaches the target floor, the ascending operation transitions to deceleration operation. During the deceleration operation, a jerk is also provided, as in the acceleration operation, and it takes several seconds for the deceleration to reach a constant value. During the deceleration operation, the motor 3 continues decelerating at the second deceleration aud after reaching a constant second deceleration aud until the speed reaches zero.

[0069] During the period in which the elevator is ascending in step S100, the processes of steps S102 to S106 are executed in sequence. Typically, in step S102, a first current value Iua is acquired at a first position P1 during acceleration operation at a constant first acceleration aua. Here, the current command value I* when the car position calculated from the rotation angle θ of the electric motor 3 detected by the rotation sensor 4 reaches the first position P1 is acquired as the first current value Iua.

[0070] In step S104, the current value Ium is acquired at a reference position during constant-speed operation. The reference position here is the middle position of the elevator's ascent / descent stroke. Here, the current command value I* when the car position calculated from the rotation angle θ of the electric motor 3 reaches the middle position is acquired as the current value Ium.

[0071] In step S106, a second current value Iud is acquired at a second position P2 during deceleration at a constant second deceleration aud. Here, the current command value I* when the car position calculated from the rotation angle θ of the electric motor 3 detected by the rotation sensor 4 reaches the second position P2 is acquired as the second current value Iud.

[0072] When the elevator's upward operation ends, the process proceeds to step S108. In step S108, the elevator's downward operation begins. Like the upward operation, the downward operation includes acceleration operation, constant speed operation, and deceleration operation. The third acceleration ada during acceleration operation in the downward direction is equal to the first acceleration aua during acceleration operation in the upward direction. Furthermore, the fourth deceleration add during deceleration operation in the downward direction is equal to the second deceleration aud during deceleration operation in the upward direction. Furthermore, a jerk is provided during acceleration operation and deceleration operation in the downward direction to improve the elevator ride comfort.

[0073] During the period when the descending operation of step S108 is being performed, the processing of steps S110 to S114 is executed in sequence. Typically, the processing of step S110 is executed at a third position P3 during acceleration operation at a constant third acceleration ada, and a third current value Ida is acquired. Here, the current command value I* when the car position calculated from the rotation angle θ of the electric motor 3 reaches the third position P3 is acquired as the third current value Ida. Note that the third position P3 here is the same position as the second position P2.

[0074] The process of step S112 is executed at the reference position during constant speed operation, and the current value Idm is acquired. Here, the current command value I* when the car position calculated from the rotation angle θ of the motor 3 reaches the intermediate position, which is the reference position, is acquired as the current value Idm.

[0075] At a fourth position P4 during deceleration operation at a constant fourth deceleration rate add, the processing of step S114 is executed to acquire a fourth current value Idd. Here, the current command value I* when the car position calculated from the rotation angle θ of the electric motor 3 detected by the rotation sensor 4 reaches the fourth position P4 is acquired as the fourth current value Idd. Note that the fourth position P4 here is the same position as the first position P1.

[0076] When the processing of step S114 is completed, the process proceeds to torque constant identification processing of step S116. Here, the torque constant identification unit 18 identifies the torque constant Kt by substituting the current value Ium acquired in step S104 and the current value Idm acquired in step S112 into equation (11). Note that the torque Uc is calculated by substituting the car load W detected by the weighing device 8 into equation (13).

[0077] When the process of step S116 is completed, the process proceeds to inertia identification process of step S118. Here, the inertia identifying unit 20 identifies the inertia J by substituting the current value Iua acquired in step S102, the current value Iud acquired in step S106, the current value Ida acquired in step S110, the current value Idd acquired in step S114, and the torque constant Kt identified in step S114 into equation (21).

[0078] When the process of step S118 is completed, the process proceeds to a gain update process of step S120. Here, the gain update unit 22 updates the P gain KP and the I gain KI by substituting the torque constant Kt identified in step S116 and the inertia J identified in step S118 into equations (22) and (23).

[0079] As is clear from the above explanation, the elevator control device 10 of the first embodiment can identify the inertia J and torque constant Kt of the elevator 100 by performing one ascending operation and one descending operation each, without requiring any special operating conditions for the elevator 100. This makes it possible to optimize the control gain used to control the hoisting machine 1, thereby making it possible to maintain constant control performance.

[0080] The torque constant and inertia are inherent values ​​of the electric motor 3 and the elevator, and do not change. For this reason, the torque constant and inertia need only be identified once when the elevator is installed. They may also be performed during maintenance and inspection. This also applies to the other embodiments described below.

[0081] 1-6. Variations The elevator 100 of the first embodiment may adopt the following modified aspects.

[0082] 1-6-1. Hardware resources of the control device 10

[0083] 4 is a diagram showing an example of hardware resources of the control device 10. The control device 10 includes, as hardware resources, a processing circuit 106 including a processor 102 and a memory 104. The processing circuit 106 may include multiple processors 102. The processing circuit 106 may include multiple memories 104.

[0084] In this embodiment, the speed detection unit 12, the speed control unit 14, the current control unit 16, the torque constant identification unit 18, the inertia identification unit 20, and the gain update unit 22 represent functions possessed by the control device 10. These functions can be realized by software written as a program, firmware, or a combination of software and firmware. The program is stored in the memory 104. Alternatively, the program may be recorded on a computer-readable recording medium. The control device 10 realizes these functions by executing the program stored in the memory 104 by the processor 102 (computer).

[0085] The processor 102 is also called a CPU (Central Processing Unit), central processing unit, processing unit, arithmetic unit, microprocessor, microcomputer, or DSP. The memory 104 may be a semiconductor memory, a magnetic disk, a flexible disk, an optical disk, a compact disk, a minidisk, or a DVD. Possible semiconductor memories include RAM, ROM, flash memory, EPROM, and EEPROM.

[0086] FIG. 5 is a diagram illustrating another example of hardware resources of the control device 10. In the example illustrated in FIG. 5, the control device 10 includes a processor 102, a memory 104, and a processing circuit 106 including dedicated hardware 108. FIG. 5 illustrates an example in which some of the functions of the control device 10 are implemented by the dedicated hardware 108. All of the functions of the control device 10 may be implemented by the dedicated hardware 108. The dedicated hardware 108 may be a single circuit, a composite circuit, a programmed processor, a parallel programmed processor, an ASIC, an FPGA, or a combination thereof. Note that the above-described variations on the hardware resources of the control device 10 can also be applied to the control device 10 of other embodiments described below.

[0087] 1-6-2. Torque constant identification process The reference position for acquiring the current values ​​Ium and Idm used in the torque constant identification process is preferably a position close to the midpoint of the ascending / descending stroke where the torques Ur and -Ur are both zero, but it does not necessarily have to be the midpoint and may be a position close to the midpoint. The reference positions for acquiring the current values ​​Ium and Idm may also be positions symmetrical about the midpoint. In this case, the torque constant identification unit 18 may acquire the current value Ium at a position −h from the midpoint during constant-speed ascending operation, and acquire the current value Idm at a position +h from the midpoint during constant-speed descending operation, for example.

[0088] 1-6-3. Inertia identification processing In the inertia identification process, the first position is preferably as close as possible to the fourth position, but does not necessarily have to be the same position, and may be, for example, a position in the vicinity of the fourth position. Similarly, the second position is preferably the same as the third position, but does not necessarily have to be the same position, and may be, for example, a position in the vicinity of the third position.

[0089] The acceleration aua during ascending operation is preferably as close as possible to the acceleration ada during descending operation, but they do not necessarily have to be the same value and may be, for example, a value close to the acceleration ada.Similarly, the deceleration aud during ascending operation is preferably as close as possible to the deceleration add during descending operation, but they do not necessarily have to be the same value and may be, for example, a value close to the deceleration add.

[0090] Embodiment 2 2-1. Features of the elevator in the second embodiment The elevator of the first embodiment described above does not consider changes in inertia J due to the addition of a load to the car 6. In contrast, the elevator of the second embodiment is characterized by control that calculates inertia J according to the car load and optimizes the control gain according to the car load.

[0091] FIG. 6 is a diagram showing the relationship between car load W and inertia J. In the example shown in this figure, inertia J identified under three different load conditions is shown. When there are multiple inertia Js under different load conditions, the inertia J corresponding to the car load W can be identified by linearly interpolating them. Note that when performing linear interpolation of inertia, it is sufficient to have identified values ​​of inertia J corresponding to at least two different load conditions. Furthermore, the interpolation method is not limited to linear interpolation, and interpolation using any function may also be used. The inertia J corresponding to the car load W is expressed by the following relational expression (24).

[0092] J = A×W+B (24)

[0093] The coefficients A and B of the relational expression shown in equation (24) can be found using the inertia J identified under different load conditions. In the example shown in FIG. 6, three points, namely the inertia J1 identified under the first load condition, the inertia J2 identified under the second load condition, and the inertia J3 identified under the third load condition, are obtained and modeled as a linear function of the car load W, and the coefficients A and B are found. Note that the linear interpolation method is not limited to the above, and it is also possible to identify inertia under more load conditions and perform linear interpolation using, for example, the least squares method. It is also possible to identify inertia under two load conditions and find the coefficients A and B.

[0094] The gain update unit 22 calculates and stores the coefficients A and B. The gain update unit 22 calculates the inertia J according to the car load W in accordance with the relational expression shown in equation (24), and updates the gain of the speed control unit 14 using the calculated inertia J. This type of control makes it possible to always control the speed of the motor 3 with the same control performance, even if the load conditions of the car 6 change. Note that the calculation of the inertia according to the load of the car 6 and the update of the speed control gain are performed after the elevator has landed on a floor, passengers have boarded and disembarked, and before the elevator starts running.

[0095] 2-2. Specific processing executed by the control device in the second embodiment Fig. 7 is a flowchart of a routine executed by the control device of the second embodiment. Note that, in the routine shown in Fig. 7, an example is described in which inertia is identified under three different load conditions, but the number of load conditions is not limited as long as it is at least two. Note that, as the number of load conditions increases, the accuracy of inertia identification improves, but the time required for inertia identification increases. Therefore, the number of load conditions should be determined taking these trade-offs into consideration.

[0096] In step S200 of the routine shown in Fig. 7, elevator ascending and descending operations are performed under a first load condition in which the car load W is W1. Here, the same processing as that in steps S100 to S114 of the routine shown in Fig. 3 is performed under the first load condition.

[0097] In the next step S202, the torque constant Kt is identified in the torque constant identification section 18. Here, the same processing as in step S116 of the routine shown in FIG.

[0098] In the next step S204, the inertia J1 is identified in the inertia identifying section 20. Here, the same processing as in step S118 of the routine shown in Fig. 3 is executed under the first load condition.

[0099] In the next step S206, elevator ascending and descending operations are performed under a second load condition in which the car load W is W2, which is different from W1. Here, under the second load condition, processing similar to the processing of steps S100 to S114 of the routine shown in FIG. 3 is performed.

[0100] In the next step S208, the inertia J2 is identified in the inertia identifying section 20. Here, the same processing as in step S118 of the routine shown in FIG. 3 is executed under the second load condition.

[0101] In the next step S210, elevator ascending and descending operations are performed under a third load condition where the car load W is W3, which is different from W1 and W2. Here, the same processing as that of steps S100 to S114 of the routine shown in FIG. 3 under the second load condition is performed.

[0102] In the next step S212, the inertia J3 is identified in the inertia identifying section 20. Here, the same processing as in step S118 of the routine shown in FIG. 3 is executed under the third load condition.

[0103] In the next step S214, the gain update unit 22 calculates the relational expression between the car load W and the inertia J. Here, the coefficients A and B of the equation (24) are calculated by linearly interpolating the inertias J1, J2, and J3.

[0104] As is clear from the above explanation, according to the elevator control device 10 of the second embodiment, the gain of the speed control unit 14 is updated using the inertia J identified in accordance with the car load of the elevator 100. This makes it possible to optimize the control gain in accordance with the car load, making it possible to maintain constant control performance even if the car load changes.

[0105] Embodiment 3 3-1. Features of the elevator control device in the third embodiment The elevator control device of embodiment 3 is characterized by a control that calculates inertia according to the load of the car 6 by adding an inertia correction value equivalent to the car load W detected by the weighing device 8 to the reference inertia identified when the car load is zero.

[0106] If the reference inertia when the car load is zero is J0 and the inertia increase due to the car load W is the inertia correction value JW, the overall inertia J can be expressed by the following equation (25).

[0107] J = J0+JW (25)

[0108] Here, for example, when the elevator 100 is a 1:1 roping elevator, JW can be calculated by the following equation (26) using the radius of the sheave 2 as r and the car load W.

[0109] JW=W×r^2 (26)

[0110] Therefore, if the reference inertia J0 when the car load is zero is identified and the car load W is measured by the weighing device 8, the inertia J according to the car load can be calculated using equations (25) and (26).

[0111] 2-2. Specific processing executed by the control device in the third embodiment Fig. 8 is a flowchart of a routine executed by the control device of embodiment 3. In step S300 of the routine shown in Fig. 8, the reference inertia J0 when the car load is zero is acquired. Here, the reference inertia J0 identified by executing the processing of the routine shown in Fig. 3 when the car load is zero is acquired.

[0112] In step S302, after elevator 100 has landed on a floor and passengers have boarded or alighted, but before elevator 100 starts running, weighing device 8 detects car load W. In the next step S304, gain update unit 22 calculates inertia J using equations (25) and (26) using the detected car load W. Then, in step S306, gain update unit 22 updates the speed control gain with the inertia J calculated in step S304. When the gain update in this routine is completed, elevator 100 starts running.

[0113] As is clear from the above explanation, according to the elevator control device 10 of the third embodiment, the inertia J is calculated using the reference inertia J0 identified when the car load is zero and the car load W detected during actual operation of the elevator 100. This makes it possible to appropriately update the gain used in the speed control unit 14 in accordance with the car load. Furthermore, inertia identification only needs to be performed when the car load is zero, which simplifies the operation required for the identification process.

[0114] 4.Other Although the preferred embodiments have been described in detail above, the present disclosure is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the claims.

[0115] Various aspects of the present disclosure are summarized below as appendices.

[0116] (Appendix 1) a speed control unit that calculates a current command value for a current flowing through the hoist so that the speed of the car traveling in the elevator shaft becomes the speed command value; a current control unit that controls the hoist so that an actual current value flowing through the hoist becomes the current command value; a torque constant identification unit that identifies a torque constant of the hoisting machine using a current value including the actual current value or the current command value and a car load acting on the car; an inertia identification unit that identifies an inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; a gain update unit that updates a gain used in calculations by the speed control unit using the inertia and the torque constant; An elevator control device comprising: (Appendix 2) The torque constant identification unit The torque constant is identified using the current value when the car passes through a reference position of the hoistway at a uniform speed during an upward operation of the elevator, the current value when the car passes through the reference position at a uniform speed during a downward operation of the elevator, and the car load. 2. The elevator control device according to claim 1, configured as follows: (Appendix 3) 3. The elevator control device according to claim 2, wherein the reference position is an intermediate position of the ascending / descending stroke of the elevator shaft. (Appendix 4) The inertia identification unit At a first position of the elevator shaft, a first current value and a first acceleration, which are the current value and the acceleration when the car is accelerating in an upward direction, are acquired; At a second position of the elevator shaft, a second current value and a second deceleration are obtained, which are the current value and the deceleration when the car is decelerating in an upward direction; calculating a first inertia identification value using the first current value, the first acceleration, the second current value, the second deceleration, and the torque constant; At a third position of the elevator shaft, a third current value and a third acceleration, which are the current value and the acceleration when the car is accelerating in a downward direction, are acquired; a fourth current value and a fourth deceleration, which are the current value and the deceleration when the car is decelerating in a downward direction at a fourth position of the elevator shaft; calculating a second inertia identified value using the third current value, the third acceleration, the fourth current value, the fourth deceleration, and the torque constant; Identifying the inertia based on the first inertia identification value and the second inertia identification value. 4. The elevator control device according to claim 1, configured as follows: (Appendix 5) The inertia identification unit 5. The elevator control device according to claim 4, wherein an average value of the first inertia identified value and the second inertia identified value is identified as the inertia. (Appendix 6) the first position is the same as the fourth position, The second position is the same as the third position. 10. An elevator control device according to claim 4 or 5. (Appendix 7) the first acceleration is equal to the third acceleration, The second deceleration is equal to the fourth deceleration. 10. An elevator control device according to any one of claims 4 to 6. (Appendix 8) the inertia identification unit is configured to identify the inertia for each of a plurality of different car loads, The gain update unit The inertia for each of the car loads is calculated by linearly interpolating each of the identified inertias, and the gain is updated for each of the car loads. 8. The elevator control device according to any one of Supplementary Note 1 to Supplementary Note 7, configured as follows: (Appendix 9) the inertia identification unit is configured to identify the inertia when the car load is zero, The gain update unit updates the gain according to the car load by using an inertia obtained by adding an inertia correction value according to the car load to the inertia identified when the car load is zero. 9. The elevator control device according to any one of Supplementary Note 1 to Supplementary Note 8, configured as follows: (Appendix 10) During the installation of the elevator, The torque constant identification unit identifies the torque constant, and the inertia identification unit identifies the inertia. 10. The elevator control device according to any one of Supplementary Note 1 to Supplementary Note 9, configured as follows: [Explanation of symbols]

[0117] 1 hoist, 2 sheave, 3 electric motor, 4 rotation sensor, 5 main rope, 6 cage, 7 counterweight, 8 weighing device, 9 current sensor, 10 control device, 12 speed detection unit, 14 speed control unit, 16 current control unit, 18 torque constant identification unit, 20 inertia identification unit, 22 gain update unit, 100 elevator, 102 processor, 104 memory, 106 processing circuit, 108 dedicated hardware

Claims

1. a speed control unit that calculates a current command value for a current flowing through the hoist so that the speed of the car traveling in the elevator shaft becomes the speed command value; a current control unit that controls the hoist so that an actual current value flowing through the hoist becomes the current command value; a torque constant identification unit that identifies a torque constant of the hoisting machine using a current value including the actual current value or the current command value and a car load acting on the car; an inertia identification unit that identifies an inertia of the elevator using the current value, the acceleration or deceleration of the car, and the torque constant; a gain update unit that updates a gain used in calculations by the speed control unit using the inertia and the torque constant; An elevator control device comprising:

2. The torque constant identification unit The torque constant is identified using the current value when the car passes through a reference position of the hoistway at a uniform speed during an upward operation of the elevator, the current value when the car passes through the reference position at a uniform speed during a downward operation of the elevator, and the car load.

2. The elevator control device according to claim 1, configured as follows:

3. 3. The elevator control device according to claim 2, wherein the reference position is a middle position of an ascending / descending stroke of the elevator shaft.

4. The inertia identification unit At a first position of the elevator shaft, a first current value and a first acceleration, which are the current value and the acceleration when the car is accelerating in an upward direction, are acquired; At a second position of the elevator shaft, a second current value and a second deceleration are obtained, which are the current value and the deceleration when the car is decelerating in an upward direction; calculating a first inertia identification value using the first current value, the first acceleration, the second current value, the second deceleration, and the torque constant; At a third position of the elevator shaft, a third current value and a third acceleration, which are the current value and the acceleration when the car is accelerating in a downward direction, are acquired; a fourth current value and a fourth deceleration, which are the current value and the deceleration when the car is decelerating in a downward direction at a fourth position of the elevator shaft; calculating a second inertia identified value using the third current value, the third acceleration, the fourth current value, the fourth deceleration, and the torque constant; Identifying the inertia based on the first inertia identification value and the second inertia identification value. The elevator control device according to any one of claims 1 to 3, configured as follows:

5. The inertia identification unit 5. The elevator control device according to claim 4, wherein an average value of the first inertia identified value and the second inertia identified value is identified as the inertia.

6. the first position is the same as the fourth position, The second position is the same as the third position. The elevator control device according to claim 4.

7. the first acceleration is equal to the third acceleration, The second deceleration is equal to the fourth deceleration. The elevator control device according to claim 4.

8. the inertia identification unit is configured to identify the inertia for each of a plurality of different car loads, The gain update unit The inertia for each of the car loads is calculated by linearly interpolating each of the identified inertias, and the gain is updated for each of the car loads. The elevator control device according to any one of claims 1 to 3, configured as follows:

9. the inertia identification unit is configured to identify the inertia when the car load is zero, The gain update unit updates the gain according to the car load by using an inertia obtained by adding an inertia correction value according to the car load to the inertia identified when the car load is zero. The elevator control device according to any one of claims 1 to 3, configured as follows:

10. During the installation of the elevator, The torque constant identification unit identifies the torque constant, and the inertia identification unit identifies the inertia. The elevator control device according to any one of claims 1 to 3, configured as follows:

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