Control device

Abstract

To provide a technology which permits the construction of an accurate and highly robust control system even for such a control target that is non-linear and whose non-linearity varies under various conditions.SOLUTION: In a control system which controls some physical amount by use of an actuator, a controller includes: means C for calculating a target operation value TgD of the actuator based on a difference e between a target value of the physical amount and an actual amount P directly or indirectly detected; and means a for calculating a driving signal of the actuator from the target operation value TgD or a second target operation value TgD2 calculated based on the target operation value TgD, in which the means a represents a relation between the operation value of the actuator and the driving signal of the actuator under the operation conditions where the response becomes slowest.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a control device, and more particularly to a control device that does not use a sensor to accommodate nonlinearity while the controlled object is nonlinear. [Background technology]

[0002] Background art of the present technology is JP 9-271185 A (Patent Document 1), which describes "an ultrasonic motor control device that controls an ultrasonic motor that interlocks with a load, and stops the motor drive to position the load when the load moves to a target position, characterized in that it is equipped with control means that gradually decelerates the motor speed from a predetermined position where the load that has moved due to motor interlocking approaches a predetermined stop position, and stops the motor drive at the motor deceleration when the load moves to the stop position." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 9-271185 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the aforementioned prior art (Patent Document 1), the target speed is predetermined for each position, and it cannot accommodate noise, mass-production variations, or changes over time, resulting in failure to draw the desired position profile trajectory and variations in response time. Furthermore, the nonlinearity and temperature sensitivity of ultrasonic motors are not taken into consideration, making similar problems likely to occur. Furthermore, because the control system is not linear, existing linear control methods such as PID control and data-driven control cannot be applied, or even if they are applied, theoretical performance is not achieved, and high control precision cannot be achieved. [Means for solving the problem]

[0005] In order to solve the above problems, for example, the configurations described in the claims are adopted. The present application includes a plurality of means for solving the above problems, for example, In a control system that uses an actuator to control some physical quantity, a means C for calculating a target operating value TgD of the actuator based on a difference e between the target value of the physical quantity and an actual physical quantity P detected directly or indirectly; a means a for calculating a drive signal for the actuator from the target operation value TgD or a second target operation value TgD2 calculated based on the target operation value TgD; The means a is the actuator The upper limit temperature at which an ultrasonic motor operates The above ultrasonic motor and the operating value of ultrasonic motor This shows the relationship between the drive signals This is a control device that features:

[0006] Also, for example, When the difference e is equal to or smaller than a predetermined value, or when the physical quantity P reaches a predetermined value, The driving signal of the actuator is further changed to 0. This is a control device that features:

[0007] Also, for example, In a control system that uses an ultrasonic motor for positioning control, The difference e between the target position and the actual position Pos detected directly or indirectly is a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the a means a for calculating a drive signal (voltage) of the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN; The means a is configured to Upper limit temperature The relationship between the rotation speed of the ultrasonic motor and the drive signal of the ultrasonic motor is shown in This is a control device that features:

[0008] Also, for example, The means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature (maximum possible temperature) when the ultrasonic motor operates and the drive signal (voltage) of the ultrasonic motor. This is a control device that features:

[0009] Also, for example, In a control system that uses an ultrasonic motor for positioning control, The difference e between the target position and the actual position Pos detected directly or indirectly is a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the a means a for calculating a drive signal (voltage) of the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN; The means a is configured to Upper limit temperature represents the relationship between the rotation speed of the ultrasonic motor and the drive signal of the ultrasonic motor in When the difference e is equal to or less than a predetermined value, or when the position Pos reaches a predetermined value, the drive signal (voltage) is changed to one that stops the ultrasonic motor. This is a control device that features:

[0010] Also, for example, In a control system that uses an ultrasonic motor for positioning control, The difference e between the target position and the actual position Pos detected directly or indirectly is a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the a means a for calculating a drive signal (voltage) of the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN; The means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature (maximum possible temperature) when the ultrasonic motor operates and the drive signal (voltage) of the ultrasonic motor, When the difference e is equal to or less than a predetermined value, or when the position Pos reaches a predetermined value, the drive signal (voltage) is changed to one that stops the ultrasonic motor. This is a control device that features:

[0011] Also, for example, The means C for calculating the target rotation speed TgN of the ultrasonic motor based on the difference e between the target position and the actual position Pos detected directly or indirectly is a PID control. This is a control device that features:

[0012] Also, for example, The means a for calculating the drive signal (voltage) of the ultrasonic motor is a means for calculating a difference d between the target rotation speed TgN and an actual rotation speed of the ultrasonic motor detected directly or indirectly; means for calculating the second target rotation speed TgN2, which is calculated so as to reduce the difference d; and means for calculating a drive signal (voltage) of the ultrasonic motor from the second target rotation speed TgN2. This is a control device that features:

[0013] Also, for example, The means for calculating the second target rotation speed TgN2, which is calculated so that the difference d becomes small, is a PID control. This is a control device that features:

[0014] Also, for example, The control system that controls some physical quantity using the actuator is configured such that the controlled object is a heater or a valve. This is a control device that features: [Effects of the Invention]

[0015] According to the present invention, a control system that controls some physical quantity using an actuator is provided with means C that calculates a target operating value TgD of the actuator based on the difference e between a target value of the physical quantity and an actual physical quantity P that is detected directly or indirectly. This makes it possible to deal with noise, mass production variations, and changes over time, makes it easier for the movement of the physical quantity P to follow a desired profile (trajectory), and reduces variations in the response time of the physical quantity P.

[0016] Furthermore, the means a for calculating the actuator drive signal from the target operation value TgD or a second target operation value TgD2 calculated based on the target operation value TgD and the means a represent the relationship between the actuator operation value and the actuator drive signal under operating conditions that result in the slowest response when the actuator operates. This means can compensate for nonlinearity of the controlled object and linearize the control system. Furthermore, since the means a is set under operating conditions that result in the slowest response of the actuator, even if the response of the actuator changes, the control system linearized by the means a only changes in the direction of increasing the response. Considering physical limitations, it is generally easier to adjust the response of a control system to slow down the response than to increase the response. As described above, the device is provided with the means C for calculating the target operating value TgD of the actuator based on the difference e between the target value of the physical quantity and the actual physical quantity P detected directly or indirectly. Therefore, even if the response of the control system linearized by the means a becomes faster, the means C can calculate the target operating value TgD appropriately (to slow down or optimize the response) so as to draw a desired profile.

[0017] For example, when position control is performed using a highly nonlinear ultrasonic motor as an actuator, means a is the relationship between the rotational speed of the ultrasonic motor at the upper limit temperature (highest possible temperature) when the ultrasonic motor operates and the drive signal (voltage) of the ultrasonic motor. In this case, even if the temperature of the ultrasonic motor drops and the responsiveness increases, the above mechanism makes it easier for the position Pos to trace a desired profile (trajectory) without using a means for detecting temperature such as a temperature sensor, and also reduces the variation in response time.

[0018] Furthermore, performance can be further improved by using PID control for the means C that calculates the target rotation speed TgN of the ultrasonic motor based on the difference e between the target position and the actual position Pos detected directly or indirectly, and by using PID control for the means that calculates the second target rotation speed TgN2, which is calculated so that the difference d between the target rotation speed TgN and the actual rotation speed of the ultrasonic motor detected directly or indirectly, becomes small. PID control is a widely used and proven control method, but it can only be applied when the controlled object is linear. By applying nonlinear compensation as described above, not only PID control but also many proven linear control methods can be applied.

[0019] Furthermore, the above configuration enables highly accurate control of the movement of the physical quantity P. Therefore, by changing the actuator drive signal to 0 when the difference e is equal to or less than a predetermined value or when the physical quantity P reaches a predetermined value, the robustness of the control can be further improved. For example, if the allowable error for control is ±f in terms of the physical quantity P, the actuator drive signal can be set to 0 when (difference e)≦f, thereby effectively utilizing the allowable error. Ultrasonic motors not only have the aforementioned nonlinearity but also large rotational fluctuations. Even if the actuator drive signal is set to 0 when (difference e)=0, the influence of rotational fluctuations makes it difficult to accurately control the position Pos to the target position. Furthermore, the influence of the inertia of the moving object makes it even more difficult to accurately control the position to the target position. By setting the actuator drive signal to 0 when (difference e)≦f, a margin equivalent to the allowable error f can be obtained, allowing for the construction of a control system that is robust against the influence of the aforementioned rotational fluctuations and inertia.

[0020] As described above, according to the present invention, it is possible to construct a highly accurate and robust control system even for a control object that is nonlinear and whose nonlinearity changes depending on various conditions. In position control using an ultrasonic motor, it is possible to draw a desired position profile trajectory without using a temperature sensor, and to achieve position control with small variation in response time, without being dependent on noise, mass production variations, or changes over time. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. [Figure 2] FIG. 2 is a system diagram of a control device in Examples 1 to 3. [Figure 3] FIG. 2 is a diagram showing a control device and a controlled object in the first embodiment. [Figure 4] FIG. 10 is a diagram showing the processing of the calculation means C in the first to third embodiments. [Figure 5] FIG. 2 is a diagram showing the processing of a calculation means a in the first embodiment. [Figure 6]FIG. 10 is a diagram showing a control device and a controlled object in a second embodiment. [Figure 7] FIG. 10 is a diagram showing the processing of the calculation means a in the second and third embodiments. [Figure 8] FIG. 10 is a diagram showing a control device and a controlled object in a third embodiment. [Figure 9] FIG. 11 is a diagram showing the processing of the calculation means b in the third embodiment. [Figure 10] FIG. 10 is a diagram showing a control device and a controlled object in a fourth embodiment. [Figure 11] FIG. 10 is a diagram showing the processing of a calculation means C in the fourth embodiment. [Figure 12] FIG. 10 is a diagram showing the processing of a calculation means a in the fourth embodiment. [Figure 13] FIG. 10 is a diagram showing the processing of the calculation means b in the fourth embodiment. [Figure 14] FIG. 13 is a diagram showing a control device and a controlled object in a fifth embodiment. [Figure 15] FIG. 13 is a diagram showing the processing of a calculation means C in the fifth embodiment. [Figure 16] FIG. 13 is a diagram showing the processing of the calculation means a in the fifth embodiment. [Figure 17] FIG. 13 is a diagram showing the processing of the calculation means b in the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, the embodiments will be described with reference to the drawings. [Example]

[0023] In this embodiment, a control system that uses an actuator to control some physical quantity comprises means C that calculates a target operating value TgD of the actuator based on a difference e between a target value of the physical quantity and an actual physical quantity P that is detected directly or indirectly, and means a that calculates a drive signal for the actuator from the target operating value TgD or a second target operating value TgD2 calculated based on the target operating value TgD, wherein the means a represents the relationship between the operating value of the actuator and the drive signal for the actuator under operating conditions that result in the slowest response when the actuator operates.

[0024] In particular, the control system, which controls positioning using an ultrasonic motor, is provided with a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the difference e between the target position and the actual position Pos detected directly or indirectly, and a means a for calculating a drive signal (voltage) of the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN, and the means a represents the relationship between the rotation speed of the ultrasonic motor and the drive signal (voltage) of the ultrasonic motor under conditions that result in the slowest response when the ultrasonic motor operates.

[0025] Also, the means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature (maximum possible temperature) when the ultrasonic motor operates and the drive signal (voltage) of the ultrasonic motor.

[0026] Furthermore, the means C for calculating the target rotation speed TgN of the ultrasonic motor based on the difference e between the target position and the actual position Pos detected directly or indirectly is a PID control.

[0027] 1 is a control block diagram showing the concept of this control device. In a control system that uses an actuator 31 to control some physical quantity P via some transfer characteristic 32, a calculation means C1 calculates a target operating value TgD of the actuator 31 based on the difference e between a target value TgP of the physical quantity P and an actual physical quantity P detected directly or indirectly. A calculation means a2 calculates a drive signal for the actuator 31 based on the target operating value TgD.

[0028] FIG. 2 is a system diagram of the device 3 that implements the above-described processes. The device 3 is provided with an input circuit 26 that processes external signals. The external signals may be, for example, sensor signals detecting a physical quantity P. These external signals pass through the input circuit 26 as input signals and are sent to the input / output port 27. The input information sent to the input / output port 27 is written to the RAM 24 via the data bus 25, or is stored in the storage device 21. The processes described below are written in the ROM 23 or the storage device 21 and executed by the CPU 22. At this time, calculations are performed using the values ​​written in the RAM 24 or the storage device 21, as appropriate. Information (values) to be sent to the outside of the calculation results are sent to the input / output port 27 via the data bus 25 and then sent as output signals to the output circuit 28. The output signals are output from the output circuit 28 to the outside. The signals to the outside here refer to, for example, the drive signals for the actuator 31.

[0029] That is, the calculation means C1 and the calculation means a2 shown in Fig. 1 are both realized by the CPU 22 shown in Fig. 2 executing the processes written in the ROM 23 or the storage device 21. Similarly, various means and functional units described below are also realized by the CPU 22 shown in Fig. 2 executing the processes written in the ROM 23 or the storage device 21.

[0030] 3 is a block diagram showing the relationship between the device 3, the ultrasonic motor 33 which is the actuator 31 controlled by the device 3, and the position Pos which is controlled by the rotation of the gear 34 in accordance with the rotation speed N of the ultrasonic motor 33. A calculation means C11 calculates a target rotation speed TgN of the ultrasonic motor 33 based on the difference e between a target position TgPos which is a control target for the position Pos and an actual position Pos detected directly or indirectly. A calculation means a12 calculates a drive signal Vu of the ultrasonic motor 33 based on the target rotation speed TgN.

[0031] Each process will be described in detail below.

[0032] <Calculation means C (Fig. 4)> In this process, the target rotation speed TgN is calculated based on the difference e. Specifically, this is shown in FIG. 4. The target rotation speed TgN is calculated using PID control based on the difference e. PID control is a well-known technique, and there are many documents that provide detailed information about it, so it will not be described in detail here.

[0033] <Calculation means a (Fig. 5)> In this process, the drive signal Vu is calculated based on the target rotation speed TgN. Specifically, this is shown in FIG. 5. The target rotation speed TgN is used as input, and the drive signal Vu is calculated by referencing TblNV. Here, TblNV represents the relationship between the rotation speed N of the ultrasonic motor 33 and the drive signal Vu of the ultrasonic motor 33 under conditions that result in the slowest response when the ultrasonic motor 33 is operating. Generally, the relationship between the rotation speed N of the ultrasonic motor 33 and the drive signal Vu is nonlinear, resulting in a curve similar to TblNV in FIG. 5, for illustrative purposes. Furthermore, this curve changes depending on the temperature of the ultrasonic motor 33; the higher the temperature, the less sensitive the rotation speed N is to the drive signal Vu. In other words, the higher the temperature of the ultrasonic motor 33, the slower the response. Here, the set value of TblNV sets the relationship between the rotation speed N of the ultrasonic motor 33 and the drive signal Vu of the ultrasonic motor 33 at the upper limit temperature (highest possible temperature) at which the ultrasonic motor 33 operates.

[0034] In this configuration, the means C11 calculates the target rotation speed TgN of the ultrasonic motor 33 by PID control based on the difference e between the target position TgPos and the actual position Pos, so that it is possible to cope with noise, mass production variations, and changes over time, the movement of the position Pos becomes easier to draw a desired profile (trajectory), and the variation in the response time of the position Pos is also reduced.

[0035] Furthermore, since the calculation means a12 sets the relationship between the rotation speed N and the drive signal Vu at the upper limit temperature when the ultrasonic motor 33 operates, which is the operating condition that causes the slowest response when the ultrasonic motor 33 operates, the control system is linearized by compensating for the nonlinearity of the ultrasonic motor 33, and since the responsiveness of the ultrasonic motor 33 only changes in the direction that makes it faster, the PID control in means C11 calculates the target rotation speed TgN appropriately (to optimize the response) so as to draw a desired profile. Therefore, even if the temperature of the ultrasonic motor 33 changes, the position Pos will stably draw a desired profile (trajectory) and the variation in response time will also be reduced, without using a temperature sensor that measures the temperature of the ultrasonic motor 33.

[0036] The above-described configuration and operation enable highly accurate and robust position control using the ultrasonic motor 33, which has strong nonlinearity and temperature characteristics. [Example]

[0037] In this embodiment, a control system that uses an actuator 31 to control some physical quantity includes means C that calculates a target operating value TgD of the actuator 31 based on the difference e between a target value of the physical quantity and an actual physical quantity P that is detected directly or indirectly, and means a that calculates a drive signal for the actuator 31 from the target operating value TgD or a second target operating value TgD2 calculated based on the target operating value TgD, and the control device is characterized in that the means a represents the relationship between the operating value of the actuator 31 and the drive signal for the actuator 31 under operating conditions that result in the slowest response when the actuator 31 operates.

[0038] In particular, the control system, which controls positioning using an ultrasonic motor 33, includes a means C for calculating a target rotational speed TgN of the ultrasonic motor 33 based on the difference e between the target position and the actual position Pos detected directly or indirectly, and a means a for calculating a drive signal (voltage) of the ultrasonic motor 33 from the target rotational speed TgN or a second target rotational speed TgN2 calculated based on the target rotational speed TgN, and the means a represents the relationship between the rotational speed of the ultrasonic motor and the drive signal (voltage) of the ultrasonic motor 33 under conditions that result in the slowest response when the ultrasonic motor 33 operates.

[0039] Also, the means a represents the relationship between the rotation speed of the ultrasonic motor 33 and the drive signal (voltage) of the ultrasonic motor 33 at the upper limit temperature (maximum possible temperature) when the ultrasonic motor 33 operates.

[0040] Furthermore, the means C for calculating the target rotation speed TgN of the ultrasonic motor 33 based on the difference e between the target position and the actual position Pos detected directly or indirectly is a PID control.

[0041] In addition, the means a for calculating the drive signal (voltage) of the ultrasonic motor 33 includes at least a means for calculating the difference d between the target rotation speed TgN and the actual rotation speed of the ultrasonic motor 33 detected directly or indirectly, a means for calculating the second target rotation speed TgN2 calculated so as to reduce the difference d, and a means for calculating the drive signal (voltage) of the ultrasonic motor 33 from the second target rotation speed TgN2.

[0042] Furthermore, the means for calculating the second target rotation speed TgN2, which is calculated so as to reduce the difference d, is PID control.

[0043] FIG. 1 is a control block diagram showing the concept of this control device, but as it has already been explained in the first embodiment, it will not be described in detail.

[0044] 2 is a system diagram of the device 3 that implements the above-mentioned processes, but as it is the same as in the first embodiment, it will not be described in detail.

[0045] 6 is a block diagram showing the relationship between the device 3, the ultrasonic motor 33 which is the actuator 31 controlled by the device 3, and the position Pos which is controlled by the rotation of the gear 34 in accordance with the rotation speed N of the ultrasonic motor 33. A calculation means C11 calculates a target rotation speed TgN of the ultrasonic motor 33 based on the difference e between a target position TgPos which is a control target for the position Pos and an actual position Pos detected directly or indirectly. A calculation means a13 calculates a drive signal Vu of the ultrasonic motor 33 based on the difference d between the target rotation speed TgN and the rotation speed N.

[0046] Each process will be described in detail below.

[0047] <Calculation means C (Fig. 4)> In this process, the target rotation speed TgN is calculated based on the difference e. Specifically, as shown in Fig. 4, this is the same as in the first embodiment, and therefore will not be described in detail.

[0048] <Calculation means a (Fig. 7)> In this process, the drive signal Vu is calculated based on the target rotation speed TgN. Specifically, this is shown in FIG. 7. The difference between the target rotation speed TgN and the rotation speed N is set to d. A second target rotation speed TgN2 is calculated using PID control based on the difference d. PID control is a well-known technique, and its details are described in many documents, so it will not be described in detail here. The second target rotation speed TgN2 is used as an input, and the drive signal Vu is determined by referring to TblNV. The specifications of TblNV here are the same as those in the first embodiment, so they will not be described in detail.

[0049] In this configuration, the means C11 calculates the target rotation speed TgN of the ultrasonic motor 33 by PID control based on the difference e between the target position TgPos and the actual position Pos, so that it is possible to cope with noise, mass production variations, and changes over time, the movement of the position Pos becomes easier to draw a desired profile (trajectory), and the variation in the response time of the position Pos is also reduced.

[0050] Furthermore, the calculation means a13 sets the relationship between the rotation speed N and the drive signal Vu at the upper limit temperature when the ultrasonic motor 33 operates, which is the operating condition that results in the slowest response when the ultrasonic motor 33 operates. Therefore, the control system is linearized by compensating for the nonlinearity of the ultrasonic motor 33. Furthermore, since the responsiveness of the ultrasonic motor 33 only changes in the direction of increasing speed, the PID control in the means C11 calculates the target rotation speed TgN appropriately (to optimize the response) so as to draw a desired profile. Furthermore, the second target rotation speed TgN2 is calculated by PID control based on the difference d between the target rotation speed TgN and the rotation speed N, so that the second target rotation speed TgN2 can be calculated more accurately depending on the situation at hand. Since this second target rotation speed TgN2 is used as the input value for nonlinear compensation, a more accurate drive signal Vu can be obtained.

[0051] Therefore, as in the first embodiment, not only is there no need to use a temperature sensor to measure the temperature of the ultrasonic motor 33, but in this embodiment, the accuracy and robustness of the control of the rotational speed N of the ultrasonic motor 33 are improved, and as a result, the position Pos traces the desired profile (trajectory) more stably, and the variation in response time is also reduced.

[0052] The above-described configuration and operation enable highly accurate and robust position control using the ultrasonic motor 33, which has strong nonlinearity and temperature characteristics. [Example]

[0053] In this embodiment, a control system that uses an actuator 31 to control some physical quantity includes means C that calculates a target operating value TgD of the actuator 31 based on the difference e between a target value of the physical quantity and an actual physical quantity P that is detected directly or indirectly, and means a that calculates a drive signal for the actuator 31 from the target operating value TgD or a second target operating value TgD2 calculated based on the target operating value TgD, and the control device is characterized in that the means a represents the relationship between the operating value of the actuator 31 and the drive signal for the actuator 31 under operating conditions that result in the slowest response when the actuator 31 operates.

[0054] In particular, the control system, which controls positioning using an ultrasonic motor 33, includes a means C for calculating a target rotational speed TgN of the ultrasonic motor 33 based on the difference e between the target position and the actual position Pos detected directly or indirectly, and a means a for calculating a drive signal (voltage) of the ultrasonic motor 33 from the target rotational speed TgN or a second target rotational speed TgN2 calculated based on the target rotational speed TgN, and the means a represents the relationship between the rotational speed of the ultrasonic motor 33 and the drive signal (voltage) of the ultrasonic motor 33 under conditions that result in the slowest response when the ultrasonic motor 33 operates.

[0055] Also, the means a represents the relationship between the rotation speed of the ultrasonic motor 33 and the drive signal (voltage) of the ultrasonic motor 33 at the upper limit temperature (maximum possible temperature) when the ultrasonic motor 33 operates.

[0056] Furthermore, the means C for calculating the target rotation speed TgN of the ultrasonic motor 33 based on the difference e between the target position and the actual position Pos detected directly or indirectly is a PID control.

[0057] In addition, the means a for calculating the drive signal (voltage) of the ultrasonic motor 33 includes at least a means for calculating the difference d between the target rotation speed TgN and the actual rotation speed of the ultrasonic motor 33 detected directly or indirectly, a means for calculating the second target rotation speed TgN2 calculated so as to reduce the difference d, and a means for calculating the drive signal (voltage) of the ultrasonic motor 33 from the second target rotation speed TgN2.

[0058] Furthermore, the means for calculating the second target rotation speed TgN2, which is calculated so as to reduce the difference d, is PID control.

[0059] When the difference e is equal to or less than a predetermined value, or when the position Pos reaches a predetermined value, the drive signal (voltage) is changed to one that stops the ultrasonic motor 33.

[0060] FIG. 1 is a control block diagram showing the concept of this control device, but as it has already been explained in the first embodiment, it will not be described in detail.

[0061] 2 is a system diagram of the device 3 that implements the above-mentioned processes, but as it is the same as in the first embodiment, it will not be described in detail.

[0062] 8 is a block diagram showing the relationship between the device 3, the ultrasonic motor 33 which is the actuator 31 controlled by the device 3, and the position Pos which is controlled by the rotation of the gear 34 in accordance with the rotation speed N of the ultrasonic motor 33. Calculation means C11 calculates a target rotation speed TgN of the ultrasonic motor 33 based on the difference e between a target position TgPos which is the control target for the position Pos and an actual position Pos detected directly or indirectly. Calculation means a13 calculates a drive signal Vu for the ultrasonic motor 33 based on the difference d between the target rotation speed TgN and the rotation speed N. Calculation means b14 changes the value of the drive signal Vu to stop the ultrasonic motor 33 when the difference e is equal to or less than a predetermined value (when the position Pos reaches a predetermined value).

[0063] Each process will be described in detail below.

[0064] <Calculation means C (Fig. 4)> In this process, the target rotation speed TgN is calculated based on the difference e. Specifically, as shown in Fig. 4, this is the same as in the first embodiment, and therefore will not be described in detail.

[0065] <Calculation means a (Fig. 7)> In this process, the drive signal Vu is calculated based on the target rotation speed TgN. Specifically, as shown in Fig. 7, this is the same as in the second embodiment, and therefore will not be described in detail.

[0066] <Calculation means b (Fig. 9)> In this process, the drive signal Vu is calculated based on the difference e. Specifically, this is shown in FIG. 7. When the difference e is equal to or less than a predetermined value, the drive signal is changed to one that stops the ultrasonic motor 33. Possible drive signals for stopping the ultrasonic motor 33 include changing the drive signal Vu of the ultrasonic motor 33 to 0 or turning off the drive switch of the ultrasonic motor 33. In addition to when the difference e is equal to or less than a predetermined value, the drive signal may also be set when the position Pos reaches a predetermined value. The predetermined value may be set, for example, as an error allowable for control, or may be set as a value that takes into account the effect of inertia (the distance traveled by inertia).

[0067] In this configuration, the means C11 calculates the target rotation speed TgN of the ultrasonic motor 33 by PID control based on the difference e between the target position TgPos and the actual position Pos, so that it is possible to cope with noise, mass production variations, and changes over time, the movement of the position Pos becomes easier to draw a desired profile (trajectory), and the variation in the response time of the position Pos is also reduced.

[0068] Furthermore, the calculation means a13 sets the relationship between the rotation speed N and the drive signal Vu at the upper limit temperature when the ultrasonic motor 33 operates, which is the operating condition that results in the slowest response when the ultrasonic motor 33 operates. Therefore, the control system is linearized by compensating for the nonlinearity of the ultrasonic motor 33. Furthermore, since the responsiveness of the ultrasonic motor 33 only changes in the direction of increasing speed, the PID control in the means C11 calculates the target rotation speed TgN appropriately (to optimize the response) so as to draw a desired profile. Furthermore, the second target rotation speed TgN2 is calculated by PID control based on the difference d between the target rotation speed TgN and the rotation speed N, so that the second target rotation speed TgN2 can be calculated more accurately depending on the situation at hand. Since this second target rotation speed TgN2 is used as the input value for nonlinear compensation, a more accurate drive signal Vu can be obtained.

[0069] Furthermore, when the difference e is equal to or less than a predetermined value (when the position Pos reaches a predetermined value), the calculation means b14 changes the value of the drive signal Vu to stop the ultrasonic motor 33, thereby making it possible to construct a control system that is robust against the effects of rotational fluctuations and inertia.

[0070] Therefore, as in the first and second embodiments, there is no need to use a temperature sensor to measure the temperature of the ultrasonic motor 33, and the accuracy and robustness of the control of the rotational speed N of the ultrasonic motor 33 are improved. As a result, the position Pos traces the desired profile (trajectory) more stably, and the response time variation is reduced, and in addition, a robust control system can be constructed.

[0071] The above-described configuration and operation enable highly accurate and robust position control using the ultrasonic motor 33, which has strong nonlinearity and temperature characteristics. [Example]

[0072] In this embodiment, a control system that uses an actuator 31 to control some physical quantity includes means C that calculates a target operating value TgD of the actuator 31 based on the difference e between a target value of the physical quantity and an actual physical quantity P that is detected directly or indirectly, and means a that calculates a drive signal for the actuator 31 from the target operating value TgD or a second target operating value TgD2 calculated based on the target operating value TgD, and the control device is characterized in that the means a represents the relationship between the operating value of the actuator 31 and the drive signal for the actuator 31 under operating conditions that result in the slowest response when the actuator 31 operates.

[0073] In addition, the control system that uses the actuator 31 to control some physical quantity controls a heater.

[0074] FIG. 1 is a control block diagram showing the concept of this control device, but as it has already been explained in the first embodiment, it will not be described in detail.

[0075] 2 is a system diagram of the device 3 that implements the above-mentioned processes, but as it is the same as in the first embodiment, it will not be described in detail.

[0076] FIG. 10 is a block diagram showing the relationship between the device 3, the heater 35 (which is the actuator 31 controlled by the device 3), and the temperature T2 controlled by heat conduction through the heat medium 36 in accordance with the temperature T1 near the heater 35. A calculation unit C15 calculates a target temperature 1 (TgT1) for the heater 35 based on the difference e between a target temperature 2 (TgT2) that is the control target for the temperature T2 and the actual temperature T2 detected directly or indirectly. A calculation unit a16a calculates a drive signal Vh for the heater 35 based on the difference d between the target temperature 1 (TgT1) and the temperature T1. A calculation unit b17 changes the value of the drive signal Vh to stop the heater 35 when the difference e is equal to or less than a predetermined value (when the temperature T2 reaches the predetermined value).

[0077] Each process will be described in detail below.

[0078] <Calculation means C (Fig. 11)> In this process, the target temperature 1 (TgT1) is calculated based on the difference e using PID control.

[0079] <Calculation means a (Fig. 12)> In this process, the drive signal Vh is calculated based on the target temperature TgT1. Specifically, this is shown in Figure 12. The difference between the target temperature TgT1 and the temperature T1 is set to d. Based on the difference d, a second target temperature, target temperature 1b (TgT1b), is calculated using PID control. The drive signal Vh is determined by inputting target temperature 1b (TgT1b) and referencing TblTV. Here, TblTV represents the relationship between the temperature T1 of the heater 35 and the drive signal Vh of the heater 35 under conditions that result in the slowest response when the heater 35 operates.

[0080] <Calculation means b (Fig. 13)> In this process, the drive signal Vh is calculated based on the difference e. Specifically, this is shown in FIG. 13. When the difference e is equal to or less than a predetermined value, the drive signal is changed to one that stops the heater 35. Alternatively, the drive signal may be changed when the temperature T2 reaches a predetermined value, in addition to when the difference e is equal to or less than the predetermined value. The predetermined value may be set, for example, as an error allowable for control, or may be set as a value that takes into account the effect of delays in heat conduction.

[0081] In this configuration, the means C15 calculates the target temperature TgT1 of the heater 35 by PID control based on the difference e between the target temperature 2 (TgT2) and the actual temperature T2. This makes it possible to deal with noise, mass production variations, and changes over time, makes it easier for the movement of the temperature T2 to follow a desired profile (trajectory), and reduces variations in the response time of the temperature T2.

[0082] Furthermore, since the calculation means a16 is set to the operating conditions that result in the slowest response when the heater 35 operates, it linearizes the control system by compensating for the nonlinearity of the heater 35. Furthermore, since the responsiveness of the heater 35 only changes in the direction of increasing speed, the PID control in means C15 calculates the target temperature TgT1 appropriately (to optimize the response) so as to draw the desired profile. Furthermore, the second target temperature TgT1b is calculated by PID control based on the difference d between the target temperature TgT1 and the temperature T1, so the second target temperature TgT1b can be calculated more accurately depending on the situation at hand. Since this second target temperature TgT1b is used as the input value for nonlinear compensation, a more accurate drive signal Vh can be obtained.

[0083] Furthermore, when the difference e is below a predetermined value (when the temperature T2 reaches a predetermined value), the calculation means b17 changes the value of the drive signal Vh to stop the heater 35, thereby making it possible to construct a control system that is robust against the effects of delays in heat conduction.

[0084] Therefore, the accuracy and robustness of the control of the temperature T1 of the heater 35 is improved, and as a result, the temperature T2 more stably follows the desired profile (trajectory), and in addition to reducing the variation in response time, a robust control system can be constructed.

[0085] The above-described configuration and operation enable highly accurate and robust temperature control using the heater 35, which has strong nonlinearity and temperature characteristics. [Example]

[0086] In this embodiment, a control system that uses an actuator 31 to control some physical quantity includes means C that calculates a target operating value TgD of the actuator 31 based on the difference e between a target value of the physical quantity and an actual physical quantity P that is detected directly or indirectly, and means a that calculates a drive signal for the actuator 31 from the target operating value TgD or a second target operating value TgD2 calculated based on the target operating value TgD, and the control device is characterized in that the means a represents the relationship between the operating value of the actuator 31 and the drive signal for the actuator 31 under operating conditions that result in the slowest response when the actuator 31 operates.

[0087] In addition, in a control system that uses the actuator 31 to control some physical quantity, the controlled object is a valve.

[0088] FIG. 1 is a control block diagram showing the concept of this control device, but as it has already been explained in the first embodiment, it will not be described in detail.

[0089] 2 is a system diagram of the device 3 that implements the above-mentioned processes, but as it is the same as in the first embodiment, it will not be described in detail.

[0090] 14 is a block diagram showing the relationship between the device 3, the valve 37 (which is the actuator 31 controlled by the device 3), and the temperature T2 controlled by heat conduction through the heat medium 38 in accordance with the valve opening Vo. A calculation means C15 calculates a target opening TgVo for the valve 37 based on the difference e between a target temperature TgT3 (which is the control target for the temperature T3) and an actual temperature T3 detected directly or indirectly. A calculation means a19 calculates a drive signal Vv for the valve 37 based on the difference d between the target opening TgVo and the opening Vo. A calculation means b20 changes the value of the drive signal Vv to stop (fully close) the valve 37 when the difference e is equal to or less than a predetermined value (when the temperature T3 reaches a predetermined value).

[0091] Each process will be described in detail below.

[0092] <Calculation means C (Fig. 15)> In this process, the target opening TgVo is calculated using PID control based on the difference e.

[0093] <Calculation means a (Fig. 16)> In this process, the drive signal Vv is calculated based on the target opening TgVo. Specifically, this is shown in Figure 16. The difference between the target opening TgVo and the opening Vo is set to d. A second target opening TgVo2 is calculated based on the difference d using PID control. The second target opening TgVo2 is used as an input, and the drive signal Vv is determined by referring to TblVV. Here, TblVV represents the relationship between the opening Vo of the valve 37 and the drive signal Vh of the valve 37 under conditions that result in the slowest response when the valve 37 operates.

[0094] <Calculation means b (Fig. 17)> In this process, the drive signal Vv is calculated based on the difference e. Specifically, this is shown in FIG. 17. When the difference e is equal to or less than a predetermined value, the drive signal is changed to one that stops (fully closes) the valve 37. Alternatively, the drive signal may be changed when the temperature T3 reaches a predetermined value, in addition to when the difference e is equal to or less than the predetermined value. The predetermined value may be set, for example, as an error allowable for control, or may be set as a value that takes into account the effect of delays in heat conduction.

[0095] In this configuration, the means C18 calculates the target opening TgVo of the valve 37 by PID control based on the difference e between the target temperature TgT3 and the actual temperature T3. This makes it possible to deal with noise, mass production variations, and changes over time, makes it easier for the movement of the temperature T3 to follow a desired profile (trajectory), and reduces variations in the response time of the temperature T3.

[0096] Furthermore, since the calculation means a19 is set to the operating conditions that result in the slowest response when the valve 37 operates, it linearizes the control system by compensating for the nonlinearity of the valve 37. Furthermore, since the responsiveness of the valve 37 only changes in the direction of increasing speed, the PID control in means C18 calculates the target opening TgVo appropriately (to optimize the response) so as to draw a desired profile. Furthermore, a second target opening TgVo2 is calculated by PID control based on the difference d between the target opening TgVo and the opening Vo, so the second target opening TgVo2 can be calculated more accurately depending on the situation at hand. This second target opening TgVo2 is used as an input value for nonlinear compensation, so a more accurate drive signal Vv can be obtained.

[0097] Furthermore, when the difference e is equal to or less than a predetermined value (when the temperature T3 reaches a predetermined value), the calculation means b20 changes the value of the drive signal Vv to stop the valve 37, thereby making it possible to construct a control system that is robust against the effects of delays in heat conduction.

[0098] Therefore, the accuracy and robustness of the control of the opening Vo of the valve 37 is improved, and as a result, the temperature T3 follows the desired profile (trajectory) more stably, and in addition to reducing the variation in response time, a robust control system can be constructed.

[0099] The above-described configuration and operation enable highly accurate and robust temperature control using the valve 37, which has strong nonlinearity and temperature characteristics.

[0100] Although several embodiments have been described above, these are merely examples for the purpose of explaining the present invention, and the scope of the present invention is not limited to these embodiments. The present invention can be implemented in various other forms.

[0101] In the above description, "RAM 24" refers to one or more memory devices (hereinafter simply referred to as "memory") that are an example of one or more storage devices, and may typically be a primary storage device. At least one memory device in the memory may be a volatile memory device or a non-volatile memory device.

[0102] In the above description, the "storage device 21" may be one or more persistent storage devices, which are an example of one or more storage devices. The persistent storage device may typically be a non-volatile storage device (e.g., an auxiliary storage device), and more specifically, may be, for example, a hard disk drive (HDD), a solid state drive (SSD), a non-volatile memory express (NVME) drive, or a storage class memory (SCM).

[0103] In the above description, the "storage device 21" may include a memory.

[0104] Furthermore, in the above description, "CPU 22" may be one or more processor devices (hereinafter simply referred to as "processor"). The at least one processor device may typically be a microprocessor device such as a CPU (Central Processing Unit) 22, but may also be another type of processor device such as a GPU (Graphics Processing Unit). The at least one processor device may be a single-core or multi-core. The at least one processor device may also be a processor core. The at least one processor device may also be a processor device in a broader sense, such as a circuit that is a collection of gate arrays written in a hardware description language that performs some or all of the processing (for example, an FPGA (Field-Programmable Gate Array), a CPLD (Complex Programmable Logic Device), or an ASIC (Application Specific Integrated Circuit)).

[0105] Furthermore, in the above description, functions are sometimes described using the expression "yyy unit." However, the functions may be realized by one or more computer programs executed by a processor, by one or more hardware circuits (e.g., FPGAs or ASICs), or by a combination thereof. When a function is realized by a program executed by a processor, the specified processing is performed using a storage device 21 and / or an interface device, etc., as appropriate, and therefore the function may be considered to be at least a part of the processor. Processing described using a function as the subject may be processing performed by a processor or a device 3 having the processor. A program may be installed from a program source. The program source may be, for example, a computer from which the program is distributed or a computer-readable recording medium (e.g., a non-transitory recording medium). The description of each function is merely an example; multiple functions may be combined into one function, or one function may be divided into multiple functions.

[0106] In addition, in the above explanation, there are cases where processing is explained using a "program" as the subject, but processing explained using a program as the subject may also be processing performed by a processor or a device 3 having that processor. Furthermore, two or more programs may be realized as one program, or one program may be realized as two or more programs.

[0107] Furthermore, in the above description, "device 3" may be a system configured with one or more physical computers, or may be a system (e.g., a cloud computing system) realized on a group of physical computing resources (e.g., a cloud platform). When device 3 "displays" the display information, it may mean that the display information is displayed on a display device possessed by the computer, or that the computer transmits the display information to a display computer (in the latter case, the display information is displayed by the display computer). [Explanation of symbols]

[0108] 1 Calculation means C 2 Calculation means a 3. Control device 11 Calculation means C 12 Calculation means a 13 Calculation means a 14 Calculation means b 15 Calculation means C 16 Calculation means a 17 Calculation means b 18 Calculation means C 19 Calculation means a 20 Calculation means b 21 Control device memory device 22 Control device CPU 23 Control device ROM 24 RAM of the control unit 25 Control device data bus 26 Control device input circuit 27 Control Unit Input / Output Ports 28 Control device output circuit 33 Ultrasonic motor 34 gears 35 Heater 36 Heat medium 37 Valve 38 Heat medium

Claims

1. In a control system that uses an actuator to control some physical quantity, a means C for calculating a target operating value TgD of the actuator based on a difference e between the target value of the physical quantity and an actual physical quantity P detected directly or indirectly; a means a for calculating a drive signal for the actuator from the target operation value TgD or a second target operation value TgD2 calculated based on the target operation value TgD; The means a represents the relationship between the operating value of the ultrasonic motor as the actuator at the upper limit temperature when the ultrasonic motor operates and the drive signal of the ultrasonic motor. A control device characterized by:

2. In claim 1, When the difference e is equal to or smaller than a predetermined value, or when the physical quantity P reaches a predetermined value, The driving signal of the actuator is further changed to 0. A control device characterized by:

3. In claim 1, In a control system that uses an ultrasonic motor for positioning control, The difference e between the target position and the actual position Pos detected directly or indirectly is a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the a means a for calculating a drive signal for the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN; The means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature when the ultrasonic motor operates and the drive signal of the ultrasonic motor. A control device characterized by:

4. In claim 1, The means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature when the ultrasonic motor operates and the drive signal of the ultrasonic motor. A control device characterized by:

5. In claim 1, In a control system that uses an ultrasonic motor for positioning control, The difference e between the target position and the actual position Pos detected directly or indirectly is a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the a means a for calculating a drive signal for the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN; The means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature when the ultrasonic motor operates and the drive signal of the ultrasonic motor, When the difference e is equal to or smaller than a predetermined value, or when the position Pos reaches a predetermined value, the drive signal is changed to a signal that stops the ultrasonic motor. A control device characterized by:

6. In claim 1, In a control system that uses an ultrasonic motor for positioning control, The difference e between the target position and the actual position Pos detected directly or indirectly is a means C for calculating a target rotation speed TgN of the ultrasonic motor based on the a means a for calculating a drive signal for the ultrasonic motor from the target rotation speed TgN or a second target rotation speed TgN2 calculated based on the target rotation speed TgN; The means a represents the relationship between the rotation speed of the ultrasonic motor at the upper limit temperature when the ultrasonic motor operates and the drive signal of the ultrasonic motor, When the difference e is equal to or smaller than a predetermined value, or when the position Pos reaches a predetermined value, the drive signal is changed to a signal that stops the ultrasonic motor. A control device characterized by:

7. 4. The method according to claim 3, wherein the means C for calculating the target rotation speed TgN of the ultrasonic motor based on the difference e between the target position and the actual position Pos detected directly or indirectly is a PID control. A control device characterized by:

8. 7. The ultrasonic motor drive signal calculating means according to claim 6, a means for calculating a difference d between the target rotation speed TgN and an actual rotation speed of the ultrasonic motor detected directly or indirectly; means for calculating the second target rotation speed TgN2, which is calculated so as to reduce the difference d; and means for calculating a drive signal for the ultrasonic motor from the second target rotation speed TgN2. A control device characterized by:

9. 9. The method according to claim 8, wherein the means for calculating the second target rotation speed TgN2, which is calculated so as to reduce the difference d, is a PID control. A control device characterized by:

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