JPH01150917A - Speed control device - Google Patents

Abstract

PURPOSE:To highly accuracy obtain a constant speed by obtaining a time of a section whenever the prescribed number of pulses is detected with a position detector, generating an aimed value from the product of the time and an aimed speed, generating a feedback quantity from the time of each section, the aimed value and a prescribed dislocation quantity, and feeding back them to a control object. CONSTITUTION:A numerical value operating processor 32, which receives an interrupting signal 40 from a coincidence circuit 20 at every time when a moving object moves for the portion of an Nr pulses, calculates a feedback signal according to algorithm. That is, first, a time T required for taking in the data of a counter 30 and moving for the portion of the Nr pulses is obtained, and an aimed dislocation Xr is calculated by the product of the time T and an aimed speed V. Further, by using the aimed dislocation Xr and a dislocation X of the moving object (that is, sensor resolution X Nr), for example, the operation of a PD controller is carried out as the controller, a feedback signal is inputted to a control object 10, and a clearing signal 38 is sent to counters 14 and 30. Thus, the moving object moves for the portion of the Nr pulses at every constant time, and the highly accurate constant speed can be realized.

Description

Detailed Description of the Invention Field of the Invention The present invention relates to a speed control device that controls the speed of a movable body using a digital position sensor that outputs pulse signals as the movable body moves linearly or rotates. It is.

Conventional technology In recent years, there has been an increasing demand for movable bodies to be driven at a constant speed with high precision in robots, 0AII devices, etc., and it is sometimes necessary to make the movable body follow a target position profile of a linear function to ensure constant speed. be.

Conventionally, as a method for making a movable body follow a target position profile, with the digitalization of position sensors and control diameters, the position and displacement of the movable body are detected at regular sampling intervals, and a feedback signal is generated from the target value and detected value. is generated and controlled.

An example of the above-mentioned conventional speed control device will be described below with reference to the drawings.

FIG. 3 shows the configuration of a conventional speed control device, in which 50 is an object to be controlled. A position sensor 52 outputs a pulse signal every time the controlled object 50 moves a certain distance. A counter 54 counts output pulses from the position sensor 52. 56 is a switch, 58 is a linear function target position signal Xr, 60 is a memory that stores the target value,
62 is a controller.

The operation of the speed control device configured as described above will be described below.

The switch 56 performs 0N10FF every fixed time T.

At this time, the target position signal Xr58 is set to a value corresponding to the number of sampling times (time) on the memory 6o, and the deviation between the counter value of the counter 54 and the target position signal Xr58 is input to the controller 62. and controller 62
generates a feedback signal from the deviation and inputs it to the controlled object 50. In this way, the controlled object 50 moves while following the target position profile. (for example,
rDC motor control circuit design JP, P, 127-1
39 Written by Kinji Tanikoshi, CQ Publishing).

Problems to be Solved by the Invention However, in the above configuration, if the position is detected every fixed sampling period T using a digital position sensor as shown in FIG. It cannot be detected and a detection error will always occur. Furthermore, the position sensor has a pitch error, and if the pitch varies sinusoidally in a certain period as shown in FIG. 5, for example, detection errors due to the pitch error will accumulate. Therefore, in order to realize highly accurate position followability and ensure constant velocity, a high-resolution sensor with small pitch error is required.

In view of the above problems, the present invention sets the sampling timing from a fixed time to a fixed distance in order to eliminate detection errors caused by sampling, and controls the speed for each displacement section of a predetermined number of pulses in order to suppress detection errors due to pitch errors. A control device is provided.

Means for Solving the Problems In order to solve the above problems, the speed control device of the present invention has the following features:
The time for each time the position detection means counts a predetermined number of pulses is determined, and the target displacement, which is a target value, is determined by the product of the time and the target speed, and the target value, the displacement for the predetermined number of pulses, and the predetermined pulse are calculated. The movable body is configured to generate a feedback signal based on the time required to move a displacement amount of several minutes and feed it back to the controlled object to control the speed of the movable body.

Effect of the Invention With the above-described configuration, the present invention generates a feedback signal every section in which the movable body moves by a predetermined number of pulses, so there is no detection error due to sampling, detection error due to pitch error is kept small, and speed is controlled with high precision. can.

Embodiment Hereinafter, a speed control device according to an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows the configuration of a speed control device in a final embodiment of the present invention. In FIG. 1, 10 is a controlled object, 12 is a position sensor that outputs a pulse signal every time the movable body moves a certain distance,
A counter 14 counts the pulses output by the position sensor 2. Two matching circuits are connected to the counter 4, 16 matching circuits are connected to the switch 24, and 20 matching circuits are connected to the numerical calculation processor 32 via the switch 34. On the other hand, 28 is an oscillation circuit that outputs pulses at a constant frequency, and 30 is a counter that counts the pulses output by the oscillation circuit 28.

The operation of the speed control position configured as described above will be explained below with reference to FIGS. 1 and 2.

Until the movable body starts moving and the counter 4 counts the preset number of pulses No. 18, the changeover switch 24 is set to the side where the constant voltage Vo26 is supplied to the controlled object, and the constant voltage Vo26 is supplied to the controlled object 10. input. During this time, the switch 34 is set to the side where the output of f120 is not input to the numerical calculation processor 32 several times. This is the startup means in this embodiment.

When the movable body moves and the counter 14 counts the preset pulse number No. 18, the minus number circuit 16
switches the switch 24 to set it to the side where the feedback signal from the numerical calculation processor 32 is input to the controlled object lO, and sets the switch 34 so that the output signal of the - number circuit 20 can be input to the numerical calculation processor 32,
Additionally, clear signals 42.
Send 44. Thereafter, the numerical arithmetic processor 32, which receives the interrupt signal 40 from the coincidence circuit 20 every time the movable body moves by Nr, calculates a feedback signal according to the algorithm shown in FIG. That is, the time T required to take in the data of the counter 30 and move by Nr is determined, and the target displacement Xr is calculated as the product of the time T and the target velocity V.

Then, using the target displacement Xr and the displacement X of the movable body (that is, the sensor resolution
Send clear signal 38 to 0.

As described above, according to this embodiment, after the movable body has moved by No pulses, it is possible to suppress detection errors due to pitch errors and eliminate detection errors due to sampling, and to move by Nr pulses at regular intervals. This makes it possible to achieve highly accurate constant speed performance.

In addition, in the embodiment, as a start-up means, a constant voltage was input to the controlled object from the start of movement until the No pulse movement, but as a start-up means, at fixed time intervals,
A target value at that time may be generated, a feedback signal may be generated, and the feedback signal may be input to the controlled object.
Although the start-up means is set to end when the start-up means has moved by the number of pulses, the start-up means may be ended when the start-up means has passed a preset position, or the start-up means may be ended when a preset time has elapsed. You may quit.

Also, what was handled by software in a numerical processor may be handled by hardware, and what was handled by hardware may be handled by software.

Additionally, a speed detection device is added to detect the speed of the moving object.
The speed signal of the speed detection device may also be used to generate the feedback signal.

Effects of the Invention As described above, the present invention calculates the time of the section every time the position detector detects a predetermined number of pulses, generates the target value from the product of the time and the target speed, and calculates the time of each section. By generating a feedback amount from the target value and a predetermined displacement amount and feeding it back to the controlled object, the position detection error is reduced and constant speed can be achieved with high accuracy.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of the speed control device in this embodiment,
The figure is a flowchart of calculations performed by the numerical calculation device in Figure 1, Figure 3 is a configuration diagram of a conventional speed control device, Figure 4 is an explanatory diagram showing conventional position detection timing and detection accuracy, and Figure 5 is an explanatory diagram showing conventional position detection timing and detection accuracy. FIG. 3 is a resolution characteristic diagram showing a pitch error of a sensor. 10...Controlled object, 12...Position sensor, 14...Counter, 16...-Several circuits, 20...-Several circuits , 24... changeover switch, 2B... oscillation circuit, 30...
... Counter, 32 ... Numerical calculation processor, 50 ... Controlled object, 52 ... Position sensor, 54 ... Counter, 58 ... ...
Target position signal, 60... Memory, 62...
··controller. Name of agent Patent attorney Toshio Nakao (1 person) Figure 2 Figure 4 Figure 7 27 3T Ginmao Figure 5

Claims (2)

[Claims] (1) A device for controlling the speed of a movable body, which includes a position sensor that outputs a pulse signal every time the movable body moves a certain amount, a position detection means that counts the pulse signal and detects the amount of displacement, and measures time. The device includes a time measuring means and a target value generating means for generating a target displacement, the time measuring means calculates the time for each section in which the movable body moves for a predetermined number of pulses, and the target value generating means calculates the time and the target displacement. A target value is generated by the product of the target speed, a controlled variable is generated using the target value, the time obtained by the time measuring means, and a displacement amount corresponding to a predetermined number of pulses, and the controlled variable is fed back. A speed control device that controls the speed of a movable body by (2) During the period from when the movable body starts operating from a stationary state until it is displaced by a predetermined number of pulses, until it passes a predetermined position, or until a predetermined time elapses, Feedback a set constant amount of control amount, or generate a control amount by the target value generation means at regular intervals using the target value as a function of time and the detected value of the position detection means, and The speed control device according to claim 1, further comprising a finishing means for feedback.