Motor selection device and motor selection method

Abstract

A motor selection device (10) includes: a speed calculation unit (16) that calculates a motor selection speed by considering iron loss generated in an object motor to be selected based on a speed waveform of a motor that drives a predetermined drive object when the predetermined drive object performs a predetermined action; a storage unit (22) that stores motor characteristics corresponding to the speed of the object motor to be selected; and a determination unit (24) that determines whether the object motor can perform an action using the motor characteristics corresponding to the motor selection speed.

Description

Technical Field

[0001] The present invention relates to a motor selection device and a motor selection method for selecting an appropriate motor. Background Art

[0002] As described in Japanese Unexamined Patent Application Publication No. 2018-153045, in a conventional motor selection device, regarding whether motor selection can be performed, it is determined by judging whether the root mean square torque during the execution of the operation mode is less than the continuous torque (rated torque) of the motor. Summary of the Invention

[0003] In the case of high-speed rotation, iron loss occurs in the motor and the heat generation increases. Therefore, when the motor is selected based on the root mean square torque being less than or equal to the continuous torque of the motor at low speed, the selection does not consider the heat generation caused by the occurrence of iron loss. The motor selected in this way has a problem of overheating during high-speed rotation. That is, in the past, the selection of the motor that did not consider the heat generation caused by the occurrence of iron loss was performed.

[0004] Here, an object of the present invention is to provide a motor selection device and a motor selection method that can perform motor selection considering the occurrence of iron loss.

[0005] A first aspect of the present invention is a motor selection device including: a speed calculation unit that calculates a motor selection speed considering iron loss generated in an object motor to be selected based on a speed waveform of a motor that drives a predetermined drive object when the drive object performs a predetermined action; a storage unit that stores motor characteristics corresponding to the speed of the object motor to be selected; and a judgment unit that judges whether the object motor can perform the action using the motor characteristics corresponding to the motor selection speed.

[0006] A second aspect of the present invention is a motor selection method for a motor selection device having a storage unit that stores motor characteristics corresponding to the speed of an object motor to be selected, the motor selection method including: a speed calculation step of calculating a motor selection speed considering iron loss generated in the object motor to be selected based on a speed waveform of a motor that drives a predetermined drive object when the drive object performs a predetermined action; and a judgment step of judging whether the object motor can perform the action using the motor characteristics corresponding to the motor selection speed.

[0007] According to the present invention, it is possible to perform motor selection considering the occurrence of iron loss.

[0008] The above objects, features, and advantages will be easily understood from the following description of the embodiments described with reference to the accompanying drawings. Brief Description of the Drawings

[0009] Figure 1 Schematic structural diagram of the motor selection device in the embodiment.

[0010] Figure 2 Diagram showing the operation mode of the driven object determined according to the operation conditions.

[0011] Figure 3 Diagram showing the speed waveform of the driven object obtained by simulation.

[0012] Figure 4 Diagram showing the torque waveform of the motor obtained by simulation.

[0013] Figure 5 Diagram showing the time change (speed waveform) of the speed of the motor.

[0014] Figure 6 Diagram showing the rated torque corresponding to the speed of the target motor.

[0015] Figure 7 Flowchart for explaining the motor selection method in the embodiment.

[0016] Figure 8 Schematic structural diagram of the motor selection device in Modification 4. Detailed Embodiment

[0017] Regarding the motor selection device and the motor selection method of the present invention, preferred embodiments are given, and the following will be described in detail with reference to the drawings.

[0018] [Embodiment]

[0019] Figure 1 Schematic structural diagram of the motor selection device 10 in the embodiment. The motor selection device 10 is a device for assisting in motor selection by showing whether the motor to be selected satisfies the performance requirements of the motor for driving a predetermined driven object when the predetermined driven object performs a specified operation.

[0020] The motor selection device 10 includes: a condition acquisition unit 12, a simulation unit 14, a speed calculation unit 16, an average torque thrust calculation unit 18, a storage unit 22, a judgment unit 24, and an output unit 26. The motor selection device 10 has a processor such as a CPU and a memory, and functions as the motor selection device 10 of the present embodiment by executing a program stored in the memory. A display unit 28 is provided outside the motor selection device 10, and the display unit 28 displays the output results from the simulation unit 14 and the output unit 26. In addition, the display unit 28 may be a part of the motor selection device 10.

[0021] The condition acquisition unit 12 acquires the mechanical conditions of a driven object (not shown) driven by a motor (not shown) and the operation conditions indicating a specified operation mode input by the user. The driven object is all driven members driven by the motor. A ball screw mechanism is provided at the front of the motor, and the table provided with the nut moves linearly by the rotational movement of the motor. Therefore, the driven members include a ball screw, a nut, a table, and a workpiece mounted on the table. In addition, in the following description, the rotational speed of the motor may sometimes be simply referred to as speed.

[0022] The mechanical conditions acquired by the condition acquisition unit 12 are physical quantities related to the driven object, including parameters such as the length and diameter of the ball screw, the mass of the table and the workpiece, and the friction coefficient. The operation conditions acquired by the condition acquisition unit 12 include parameters that define a specified operation mode, such as the moving distance and moving speed of the table and the workpiece. Based on the mechanical conditions and operation conditions acquired by the condition acquisition unit 12, a specified operation performed by a pre-determined driven object is determined, so the condition acquisition unit 12 outputs the acquired mechanical conditions and operation conditions to the simulation unit 14.

[0023] Based on the mechanical conditions and operation conditions input by the condition acquisition unit 12, the simulation unit 14 obtains, by simulation, the speed waveform and torque waveform of the motor that drives the driven object when performing a specified operation in the pre-determined driven object.

[0024] Figure 2 It is a diagram showing the operation mode of the driven object determined according to the operation conditions. Figure 2 The horizontal axis represents time, and the vertical axis represents the position of the table (or the workpiece). In Figure 2 , it shows an operation mode in which the table (or the workpiece) moves 1 m in a specified direction and stops within a specified time period.

[0025] Figure 3 It is a diagram showing the speed waveform of the driven object obtained by simulation. Figure 3 The horizontal axis represents time, and the vertical axis represents the speed of the table (or the workpiece). Therefore, in Figure 3 , if the unit of the vertical axis is changed, it becomes the speed waveform of the motor. Figure 4 It is a diagram showing the torque waveform of the motor obtained by simulation. Figure 4 The horizontal axis represents time, and the vertical axis represents the torque of the motor. The simulation unit 14 can obtain, as in Figure 3 and Figure 4 , the speed waveform and torque waveform of the rotation of the motor when the driven object performs the operation of Figure 2 , and displays them together with Figure 2 on the display unit 28 and presents them to the user.

[0026] The speed calculation unit 16 calculates the motor selection speed considering the iron loss generated in the target motor based on the speed waveform of the motor obtained through the simulation by the simulation unit 14. The speed calculation unit 16 outputs the calculated motor selection speed to the determination unit 24.

[0027] Hereinafter, a method for the speed calculation unit 16 to calculate the motor selection speed considering the iron loss generated in the target motor based on the speed waveform will be described. First, using the coefficient A and the coefficient B determined depending on the target motor, the iron loss generated by the motor is expressed as iron loss = A × speed + B × (speed) 2 is expressed as.

[0028] Figure 5 is a graph showing the time variation (speed waveform) of the speed of the motor. The vertical axis represents the (rotational) speed of the motor, and the horizontal axis represents time. Figure 5 It is shown that during the period of time t1, the speed is maintained at N1; during the period of time t2, the speed is maintained at N2..., and during the period of time tn, the speed is maintained at Nn. And such a speed change repeats with a period of time T. Here, T = t1 + t2 +... + tn. In such a case, the total amount of heat generation X due to the iron loss of the target motor for the coefficients A and B is expressed by the following formula (1).

[0029] X = A × (N1 × t1 + N2 × t2 +... + Nn × tn) + B × (N1 2 × t1 + N2 2 × t2 +... + Nn 2 × tn) ··· (1)

[0030] And the heat generation amount per unit time Y is expressed by the following formula (2).

[0031] Y = A × (N1 × t1 + N2 × t2 +... + Nn × tn) / T + B × (N1 2 × t1 + N2 2 × t2 +... + Nn 2 × tn) / T ··· (2)

[0032] Here, (N1 × t1 + N2 × t2 +... + Nn × tn) / T is the average speed Nmean obtained by performing an addition average operation based on the speed waveform, and (N1 2 × t1 + N2 2 × t2 +... + Nn 2 × tn) / T is the square of the root mean square speed Nrms obtained by performing a root mean square operation based on the speed waveform. Therefore, the heat generation amount per unit time Y can be expressed by the following formula (3).

[0033] Y = A × Nmean + B × Nrms2 ···(3)

[0034] Here, the speed at which the motor has a constant speed and generates a heat generation rate per unit time equal to Y in the equation (3) is defined as the motor selection speed Ns, and the following relationship holds.

[0035] A×Nmean + B×Nrms 2 = A×Ns + B×Ns 2 ···(4)

[0036] When solving Equation (4) for Ns and selecting the positive solution, Ns becomes the following Equation (5)

[0037]

[0038] As described above, the speed calculation unit 16 obtains the motor selection speed Ns. By using Equation (5), the motor selection speed considering iron loss can be obtained with high accuracy.

[0039] The average torque thrust calculation unit 18 calculates the root mean square torque based on the torque waveform obtained through the simulation by the simulation unit 14 and outputs it to the determination unit 24.

[0040] The storage unit 22 stores motor characteristics corresponding to the speed of the target motor to be selected. Here, the motor characteristics stored in the storage unit 22 are the rated torque. Therefore, the storage unit 22 stores the relationship of the rated torque corresponding to the speed for each of the multiple motors. Figure 6 Is a graph showing the rated torque corresponding to the speed of the target motor. Figure 6 The vertical axis represents torque and the horizontal axis represents speed. Since the target motor can continuously operate at a torque below the rated torque at each speed, such a torque region is shown as the continuous operation region.

[0041] The determination unit 24 determines whether the target motor can perform a specified operation on the drive target by using the motor characteristics corresponding to the motor selection speed. Specifically, the determination unit 24 compares the root mean square torque obtained from the average torque thrust calculation unit 18 with the rated torque corresponding to the motor selection speed of the target motor obtained by accessing the storage unit 22. And, the determination unit 24 determines whether the root mean square torque is below the above-mentioned rated torque. When the root mean square torque is below the rated torque, the target motor can be used to perform a specified operation on a pre-determined drive target. Here, the target motor as the comparison object is the motor selected as the selection target from among the multiple motors having the relationship of the rated torque corresponding to the speed stored in the storage unit 22.

[0042] For example, in Figure 6When the root-mean-square torque value calculated by the average torque thrust calculation unit 18 is A0, the point a where the root-mean-square torque value at the motor selection speed obtained by the speed calculation unit 16 is A0 is included in the continuous operation region. In this case, the determination unit 24 determines that the root-mean-square torque is below the rated torque, and the drive object can perform a specified action by the target motor. In addition, when the root-mean-square torque value calculated by the average torque thrust calculation unit 18 is B0, the point b where the root-mean-square torque of the motor selection speed obtained by the speed calculation unit 16 is B0 is not included in the continuous operation region. In this case, the determination unit 24 determines that the root-mean-square torque is not below the rated torque, and the drive object cannot perform a specified action by the target motor. The determination unit 24 outputs the above determination result to the output unit 26.

[0043] The output unit 26 outputs a report signal reporting the determination result from the determination unit 24. The content of the report signal output by the output unit 26 is displayed by the display unit 28, and it is reported to the user whether the target motor can be used.

[0044] Figure 7 It is a flowchart for explaining the motor selection method in the embodiment. Before Figure 7 the start of the process, the condition acquisition unit 12 outputs the acquired mechanical conditions and operation conditions to the simulation unit 14.

[0045] First, the simulation unit 14 simulates the speed waveform and torque waveform of the rotation of the motor that drives the drive object when the pre-determined drive object performs a specified action according to the mechanical conditions and operation conditions input through the condition acquisition unit 12 (step S1).

[0046] Next, the speed calculation unit 16 calculates the motor selection speed based on the speed waveform obtained in step S1 and outputs it to the determination unit 24 (step S2).

[0047] The average torque thrust calculation unit 18 calculates the root-mean-square torque based on the torque waveform obtained in step S1 and outputs it to the determination unit 24 (step S3).

[0048] The determination unit 24 compares the root-mean-square torque calculated by the average torque thrust calculation unit 18 with the rated torque of the target motor corresponding to the motor selection speed obtained by the speed calculation unit 16, and determines whether the root-mean-square torque is below the rated torque (step S4). The determination unit 24 outputs the determination result of whether the target motor can make the drive object perform a specified action according to the determination in step S4 to the output unit 26.

[0049] The output unit 26 outputs a report signal reporting the determination result of the determination unit 24 (step S5), and the content of the report signal is displayed on the display unit 28.

[0050] As described above, the motor selection device 10 of the present embodiment compares the root mean square torque with the rated torque of the motor to be selected corresponding to the motor selection speed. By determining whether the root mean square torque is less than or equal to the rated torque, it is possible to determine whether the target motor can cause the driven object to perform a specified operation. Therefore, the motor can be selected considering the iron loss generated in the motor. As a result, a more suitable motor can be selected than in the past.

[0051] [Modification Example]

[0052] The above-described embodiment can be modified as follows.

[0053] (Modification Example 1)

[0054] In the above-described embodiment, the speed calculation unit 16 considers the iron loss generated in the target motor and uses Equation (5) to obtain the motor selection speed Ns. Since Equation (5) is relatively complex, in Modification Example 1, the root mean square speed Nrms obtained by the speed calculation unit 16 performing root mean square operation according to the speed waveform is regarded as an approximation of Equation (5) and used as the motor selection speed. Thus, it is possible to obtain the motor selection speed with less computational cost while considering the iron loss generated in the target motor.

[0055] (Modification Example 2)

[0056] In the above-described embodiment, the speed calculation unit 16 considers the iron loss generated in the target motor and uses Equation (5) to obtain the motor selection speed Ns. Since Equation (5) is relatively complex, in Modification Example 2, the average speed Nmean obtained by the speed calculation unit 16 performing addition average operation according to the speed waveform is regarded as an approximation of Equation (5) and used as the motor selection speed. Thus, it is possible to obtain the motor selection speed with less computational cost while considering the iron loss generated in the target motor.

[0057] (Modification Example 3)

[0058] In the above-described embodiment, the motor is a rotary motor, but in Modification Example 3, the motor is a linear motor that does not perform rotational motion. In Modification Example 3, the simulation unit 14 obtains, by simulation, the speed waveform and thrust waveform of the motor that drives the driven object when causing a predetermined driven object to perform a specified operation, based on the mechanical conditions and operation conditions input through the condition acquisition unit 12.

[0059] Next, the average torque thrust calculation unit 18 calculates the root mean square thrust based on the thrust waveform of the motor obtained from the simulation by the simulation unit 14, and outputs it to the determination unit 24. In addition, the motor characteristics corresponding to the speed of the target motor stored in the storage unit 22 are the rated thrust. The determination unit 24 compares the root mean square thrust obtained from the average torque thrust calculation unit 18 with the rated thrust corresponding to the motor selection speed of the target motor obtained by accessing the storage unit 22.

[0060] Next, the determination unit 24 determines whether the root mean square thrust is equal to or less than the above-mentioned rated thrust. When the root mean square thrust is equal to or less than the rated thrust, it can be determined that the target motor can be used to cause a predetermined drive object to perform a predetermined action. In this way, it is possible to select a linear motor that is more suitable than before considering iron loss.

[0061] (Modification Example 4)

[0062] Figure 8 It is a schematic structural diagram of the motor selection device 10 of Modification Example 4. Figure 8 In the motor selection device 10 of Figure 1 the average torque thrust calculation unit 18 is replaced by an average current calculation unit 30. In Modification Example 4, the simulation unit 14 obtains the speed waveform and current waveform of the motor that drives the drive object when causing a predetermined drive object to perform a predetermined action through simulation based on the mechanical conditions and operation conditions input by the condition acquisition unit 12.

[0063] Next, the average current calculation unit 30 calculates the root mean square current based on the current waveform of the motor obtained from the simulation by the simulation unit 14, and outputs it to the determination unit 24. In addition, the motor characteristics corresponding to the speed of the target motor stored in the storage unit 22 are the rated current. The determination unit 24 compares the root mean square current obtained from the average current calculation unit 30 with the rated current corresponding to the motor selection speed of the target motor obtained by accessing the storage unit 22.

[0064] Next, the determination unit 24 determines whether the root mean square current is equal to or less than the above-mentioned rated current. When the root mean square current is equal to or less than the rated current, it can be determined that the target motor can be used to cause a predetermined drive object to perform a predetermined action. Thus, in the case of using the current waveform of the motor, it is possible to select a more suitable motor than before considering iron loss.

[0065] (Modification Example 5)

[0066] In the above-described embodiments, Modification 3, and Modification 4, the speed waveform, torque waveform, thrust waveform, and current waveform of the motor are obtained by performing simulation by the simulation unit 14, but they may also be measured values obtained in advance. Based on these measured values, the speed calculation unit 16, the average torque thrust calculation unit 18, and the average current calculation unit 30 can calculate the motor selection speed, root mean square torque, root mean square thrust, and root mean square current. Thus, the simulation can be omitted.

[0067] (Modification 6)

[0068] The above-described embodiments and modifications can be appropriately combined within a range where no contradiction occurs.

[0069] [Invention Obtainable from the Embodiment]

[0070] Regarding the invention that can be grasped from the above-described embodiment, it is described as follows.

[0071] (First Invention)

[0072] The motor selection device (10) includes: a speed calculation unit (16) that calculates a motor selection speed by considering iron loss generated in the target motor to be selected based on the speed waveform of the motor that drives a predetermined drive object when the predetermined drive object performs a predetermined action; a storage unit (22) that stores motor characteristics corresponding to the speed of the target motor to be selected; and a determination unit (24) that determines whether the target motor can operate using the motor characteristics corresponding to the motor selection speed.

[0073] Thereby, it is possible to select a motor while considering the iron loss that occurs in the motor, and it is possible to perform a more appropriate motor selection than in the past.

[0074] The motor selection device (10) may further include at least one of an average torque thrust calculation unit (18) or an average current calculation unit (30). The average torque thrust calculation unit calculates the root mean square torque or the root mean square thrust based on the torque waveform or the thrust waveform of the motor that drives the drive object when the drive object performs an action, and the average current calculation unit calculates the root mean square current based on the current waveform of the motor; and an output unit (26) that outputs a report signal reporting the determination result of the determination unit (24). The motor characteristics are the rated torque, rated thrust, or rated current of the target motor, and the determination unit can determine whether the root mean square torque, the root mean square thrust, or the root mean square current is equal to or less than the rated torque, the rated thrust, or the rated current of the target motor corresponding to the motor selection speed.

[0075] The speed calculation unit (16) uses a coefficient A and a coefficient B determined depending on the target motor, where iron loss = A × speed + B × (speed) 2When expressed in this way, when the average speed obtained from the speed waveform is set as Nmean, the root mean square speed obtained from the speed waveform is set as Nrms, and the motor selection speed is set as Ns, the relational expression is used to calculate the motor selection speed. Thereby, it is possible to accurately select a motor while taking into account the iron loss occurring in the motor.

[0076] The speed calculation unit (16) may also perform a root mean square operation to calculate the motor selection speed. Thereby, while taking into account the iron loss generated in the target motor, the motor selection speed can be obtained with less computational cost.

[0077] The speed calculation unit (16) may also perform an additive average operation to calculate the motor selection speed. Thereby, while taking into account the iron loss generated in the target motor, the motor selection speed can be obtained with less computational cost.

[0078] (Second Invention)

[0079] A motor selection method for a motor selection device (10) having a storage unit (22), the storage unit (22) storing motor characteristics corresponding to the speed of a target motor to be selected, the motor selection method including: a speed calculation step of calculating a motor selection speed in consideration of the iron loss generated in the target motor to be selected based on the speed waveform of the motor that drives a predetermined drive object when the predetermined drive object performs a predetermined action; and a determination step of determining whether the target motor can perform the action using the motor characteristics corresponding to the motor selection speed.

[0080] Thereby, it is possible to select a motor while taking into account the iron loss occurring in the motor, and it is possible to perform a more appropriate motor selection than in the past.

[0081] The motor selection method may further include at least one of an average torque thrust calculation step or an average current calculation step. The average torque thrust calculation step calculates the root mean square torque or the root mean square thrust based on the torque waveform or the thrust waveform of the motor that drives the drive object when the drive object performs an action, and the average current calculation step calculates the root mean square current based on the current waveform of the motor; and an output step of outputting a report signal reporting the determination result of the determination step. The motor characteristics are the rated torque, the rated thrust, or the rated current of the target motor, and the determination step may determine whether the root mean square torque, the root mean square thrust, and the root mean square current are equal to or less than the rated torque, the rated thrust, or the rated current of the target motor corresponding to the motor selection speed.

[0082] The speed calculation step uses a coefficient A and a coefficient B determined depending on the target motor, with iron loss = A × speed + B × (speed) 2When represented by, when the average speed obtained from the speed waveform is set as Nmean, the root mean square speed obtained from the speed waveform is set as Nrms, and the motor selection speed is set as Ns, the relational expression can be used to calculate the motor selection speed. Thereby, it is possible to accurately select a motor while taking into account the iron loss occurring in the motor.

[0083] The speed calculation step may also perform a root mean square operation to calculate the motor selection speed. Thereby, on the basis of taking into account the iron loss generated in the target motor, the motor selection speed can be obtained with less computational cost.

[0084] The speed calculation step may also perform an additive average operation to calculate the motor selection speed. Thereby, on the basis of taking into account the iron loss generated in the target motor, the motor selection speed can be obtained with less computational cost.

Claims

1. A motor selection device, characterized in that, Comprising: a speed calculation unit that calculates a motor selection speed by considering iron loss generated in an object motor to be selected, based on a speed waveform of a motor that drives a predetermined drive object when the drive object performs a predetermined action; a storage unit that stores motor characteristics corresponding to the speed of the object motor to be selected; a determination unit that determines whether the object motor can perform the action by using the motor characteristics corresponding to the motor selection speed; at least one of an average torque thrust calculation unit or an average current calculation unit, the average torque thrust calculation unit calculates a root mean square torque or a root mean square thrust based on a torque waveform or a thrust waveform of the motor that drives the drive object when the drive object performs the action, and the average current calculation unit calculates a root mean square current based on the current waveform of the motor; and an output unit that outputs a report signal reporting the determination result of the determination unit, wherein the motor characteristics are the rated torque, rated thrust or rated current of the object motor, and the determination unit determines whether the root mean square torque, the root mean square thrust or the root mean square current is less than or equal to the rated torque, rated thrust and rated current of the object motor corresponding to the motor selection speed.

2. The motor selection device according to claim 1, characterized in that The speed calculation unit uses coefficient A and coefficient B determined depending on the target motor, and when expressed as iron loss = A × speed + B × (speed) 2 when the average speed obtained from the speed waveform is set to Nmean, the root mean square speed obtained from the speed waveform is set to Nrms, and the motor selection speed is set to Ns, the relational expression is used the motor selection speed is calculated.

3. The motor selection device according to claim 1 or 2, characterized in that the speed calculation unit performs a root mean square operation to calculate the motor selection speed.

4. The motor selection device according to claim 1 or 2, characterized in that the speed calculation unit performs an additive average operation to calculate the motor selection speed.

5. A motor selection device, characterized in that, Comprising: a speed calculation unit that calculates a motor selection speed by considering iron loss generated in an object motor to be selected, based on a speed waveform of a motor that drives a predetermined drive object when the drive object performs a predetermined action; a storage unit that stores motor characteristics corresponding to the speed of the object motor to be selected; and a determination unit that determines whether the object motor can perform the action by using the motor characteristics corresponding to the motor selection speed, The speed calculation unit uses coefficient A and coefficient B determined depending on the target motor, and when expressed as iron loss = A × speed + B × (speed) 2 in the case where, when the average speed obtained from the speed waveform is set to Nmean, the root mean square speed obtained from the speed waveform is set to Nrms, and the motor selection speed is set to Ns, the relational expression is used calculating the motor selection speed.

6. The motor selection device according to claim 5, characterized in that the speed calculation unit performs a root mean square operation to calculate the motor selection speed.

7. The motor selection device according to claim 5, characterized in that the speed calculation unit performs an additive average operation to calculate the motor selection speed.

8. A motor selection method of a motor selection device, the motor selection device having a storage unit, the motor selection method is characterized in that the storage unit stores motor characteristics corresponding to the speed of the object motor to be selected, the motor selection method includes: A speed calculation step that calculates a motor selection speed by considering iron loss generated in the object motor that becomes the selection object, based on the speed waveform of a motor that drives a predetermined drive object when the drive object performs a predetermined action; A judgment step that uses the motor characteristics corresponding to the motor selection speed to judge whether the object motor can perform the action; At least one of an average torque thrust calculation step or an average current calculation step. The average torque thrust calculation step calculates the root mean square torque or the root mean square thrust based on the torque waveform or the thrust waveform of the motor that drives the drive object when the drive object performs the action, and the average current calculation step calculates the root mean square current based on the current waveform of the motor; and An output step that outputs a report signal reporting the judgment result of the judgment step, The motor characteristics are the rated torque, the rated thrust, or the rated current of the object motor, The judgment step judges whether the root mean square torque, the root mean square thrust, or the root mean square current is less than or equal to the rated torque, the rated thrust, or the rated current of the object motor corresponding to the motor selection speed.

9. The motor selection method according to claim 8, wherein The speed calculation step uses coefficient A and coefficient B determined depending on the object motor, where iron loss = A × speed + B × (speed) 2 In the case of expressing, when the average speed obtained from the speed waveform is set as Nmean, the root mean square speed obtained from the speed waveform is set as Nrms, and the motor selection speed is set as Ns, the relational expression is used The motor selection speed is calculated.

10. The motor selection method according to claim 8 or 9, wherein The speed calculation step performs a root mean square operation to calculate the motor selection speed.

11. The motor selection method according to claim 8 or 9, wherein The speed calculation step performs an additive average operation to calculate the motor selection speed.

12. A motor selection method for a motor selection device, the motor selection device having a storage unit, the motor selection method being characterized in that The storage unit stores motor characteristics corresponding to the speed of the object motor that becomes the selection object, The motor selection method includes: A speed calculation step that calculates a motor selection speed by considering iron loss generated in the object motor that becomes the selection object, based on the speed waveform of a motor that drives a predetermined drive object when the drive object performs a predetermined action; A judgment step that uses the motor characteristics corresponding to the motor selection speed to judge whether the object motor can perform the action, The speed calculation step uses coefficient A and coefficient B determined depending on the object motor, and when expressed as iron loss = A × speed + B × (speed) 2 in the case where the average speed obtained from the speed waveform is set as Nmean, the root mean square speed obtained from the speed waveform is set as Nrms, and the motor selection speed is set as Ns, the relational expression The motor selection speed is calculated.

13. The motor selection method according to claim 12, wherein The speed calculation step performs a root mean square operation to calculate the motor selection speed.

14. The motor selection method according to claim 12, wherein The speed calculation step performs an additive average operation to calculate the motor selection speed.

Images