JP5353386B2 - Motor drive device - Google Patents

Description

  The present invention relates to a motor drive device having a function of taking a motor position from a motor position detector by serial communication and detecting a motor position at an input timing of an external input signal.

  Conventionally, a motor that takes in a motor position from a motor position detector through serial communication at the timing of a motor position latch signal generated at a constant sampling cycle, and stores the motor position at a timing when an external input signal is turned on after passing through a certain point. The drive unit stores the value of the internal counter at the timing of each edge of the motor position latch signal and the external input signal in order to increase the detection accuracy of the stored motor position. Even when the motor is turned on, the motor position at the timing when the external input signal is turned on is estimated using the stored value of the internal counter (see, for example, Patent Document 1).

JP 2008-220116 A

  The problem to be solved is a detection accuracy error due to the transmission delay of the external input signal, and particularly when the motor operates at high speed, the influence of the delay time becomes large, and the motor position cannot be estimated accurately. When two external input signals are input and the relative position between each point is detected, if the motor operates at high speed, the influence of the delay time difference between the external input signals becomes large, and the relative position cannot be estimated with high accuracy. .

  The present invention solves the above-mentioned conventional problems, and provides a motor drive device capable of accurately estimating the relative position even when the difference in transmission delay time between two external input signals is large and the motor operates at high speed. The purpose is to do.

  In order to solve the above-mentioned problem, a motor drive device according to claim 1 is a motor control unit for generating a motor position latch signal at a constant period, and a motor position through serial communication means at the input timing of the motor position latch signal. Motor position capturing means for capturing and storing a position counter value in the detector, and an internal counter at the input timing of each of the motor position latch signal and two external input signals (first external input signal and second external input signal) Counter storage means for storing each value of the motor, detection position calculation means for estimating the motor position change amount from the motor position latch until the external input signal is turned on, and calculating the motor position at the input timing of the external input signal; The first internal counter captured by transmitting the first external input signal when two external input signals are simultaneously turned on And an inter-input signal delay calculating means for calculating a difference between the second internal counter value taken in by transmission of the second external input signal and storing it as a relative delay correction amount, and the detection position calculating means includes the inter-input signal delay The motor position at the input timing of the second external input signal is calculated by subtracting the relative delay correction amount calculated by the calculation means from the second internal counter value.

The motor drive device according to claim 2 is provided with parameter storage means which is a nonvolatile storage means for storing the relative delay correction amount calculated by the delay calculation means between the input signals, and the motor drive device is turned on again. Later, the detection position calculation means reads the relative delay correction amount from the parameter storage means, thereby omitting the recalculation of the relative delay correction amount.

  According to the motor drive device of the first aspect, the relative position can be accurately estimated even when the transmission delay time difference between the two external input signals is large and the motor operates at high speed.

  According to the motor drive device of the second aspect, by storing the calculated relative position delay correction amount in the nonvolatile storage means, the recalculation of the relative position delay correction amount after the motor drive device is turned on again. It becomes unnecessary.

Explanatory drawing of the principal part of the motor drive device in Example 1 of this invention. Explanatory drawing of the delay calculation means between input signals in Example 1 of this invention. Explanatory drawing of the detection position calculating means in Example 1 of this invention Configuration diagram of the main part of the motor drive device in Embodiment 2 of the present invention

Example 1
The first embodiment is a basic configuration of the present invention, and a usage example in which the motor positions at two points are detected and the relative positions thereof are accurately calculated will be described with reference to the drawings.

  FIG. 1 is an explanatory diagram of a main part, in which a motor 20 with a motor position detector 21 is connected to a motor driving device 10, and the motor driving device 10 uses a value of a motor position counter detected by the motor position detector 21 for a certain period. In (motor control cycle), the motor position is fetched into the motor position fetching means 14 through the serial communication means 19, the value is inputted to the motor control means 15, and the motor control processing position counter is updated to perform motor position feedback control.

  Here, the motor position fetching means 14 has a motor timing at which the motor position latch signal 18 generated by the motor control means 15 at a constant cycle (motor control cycle) is turned on (here, Low when turned on and High when turned off). The value of the position counter is taken in.

  The internal counter 11 detects the first external input signal 24 that is turned on when passing through the first point (here, Low when turned on, and High when turned off) and the second external input signal 25 that is turned on when passing the second point. The position calculation means 13 and the inter-input signal delay calculation means 16 are input, and the motor position latch signal 18 is also input from the motor control means 15 to the internal counter 11.

  Here, the internal counter 11 is a 16-bit free-run counter (counting up from 0000h to FFFFh, returning to 0 and counting up again when exceeding FFFFh). The internal counter 11 copies and stores (latches) the value of the internal counter in the counter storage means 12 at the timing when the input signal is turned on (falling edge that changes from High to Low).

  The storage areas latched in the counter storage means 12 are distinguished for the three input signals, the CH0 latch register, the CH1 latch register, and the CH2 latch register. Here, the motor position latch signal 18 is stored in the CH0 latch register, the first external input signal 24 is stored in the CH1 latch register, and the second external input signal 25 is stored in the CH2 latch register.

Next, the internal processing of the input signal delay calculation means 16 will be described with reference to FIG. In order to measure the transmission delay time difference between the two input signals, one sensor output signal is connected to both the first external input signal and the second external input signal and connected to the motor drive device 10. The signal reaches the internal counter 11 through each transmission path, the first external input signal 24 side stores the internal counter value Cap1 in the CH1 latch register of the counter storage means 12, and the second external input signal 25 side stores the CH2 latch register. Stores the internal counter value Cap2. The inter-input signal delay calculating means 16 calculates the difference between the internal counter value Cap2 and the internal counter value Cap1 as a relative delay correction amount.

Relative delay correction amount = Cap2-Cap1
Note that delay 1 shown in FIG. 2 is a transmission delay time outside the motor driving device such as a cable delay, delay 2 is a transmission delay time of a photocoupler, resistor, capacitor, etc. in the motor driving device, and delay 3 is an IC inside the motor driving device. Assumes transmission delay time due to multiple readings.

  Next, the internal processing of the detection position calculation means 13 will be described using FIG. The detection position calculation process is performed at a constant cycle (motor control cycle). First, the detected position calculating means 13 takes in the latest motor position taken in by the motor position taking means 14 and stores it in the variable Pos (k). In the figure, Pos (k) is the latest value, Pos (k-1) is the value one cycle before, Pos (k-2) is the value two cycles ago, and the past motor positions are stored several times. ing. Further, the latest value of the CH0 latch register fetched by the motor position latch signal 18 from the counter storage means 12 is fetched and stored in the variable Cap0 (k). In the figure, Cap0 (k) is the latest value, Cap0 (k-1) is the value one cycle before, and Cap0 (k-2) is the value two cycles before, so the past CH0 latch register is stored several times. ing.

  The motor position Pos1 at the timing of the first point passage (edge at which the first external input signal 24 is turned on) in FIG. 3 is obtained by the following calculation formula.

Pos1 = Pos (k−4) + estimated change 1
Estimated change 1 = (Pos (k−2) −Pos (k−4))
× (Cap1-Cap0 (k-4))
/ (Cap0 (k-2) -Cap0 (k-4))
Further, Pos2 ′ corrected by adding the relative delay correction amount to the motor position Pos2 at the timing of the second point passage (edge at which the second external input signal 25 is turned on) in FIG. 3 is obtained by the following calculation formula.

Pos2 ′ = Pos (k−2) + estimated change amount 2
Estimated variation 2 = (Pos (k) −Pos (k−2))
× ((Cap2-relative delay correction amount) -Cap0 (k-2))
/ (Cap0 (k) -Cap0 (k-2))
Therefore, the corrected value Pr of the relative positions of the first point and the second point can be obtained by the following calculation formula.

Pr = Pos2′−Pos1
The relative position Pr calculated by the detection position calculation means 13 is output as a monitor value 23 through the motor control means 15. The host device can know the relative positional relationship between the two points by referring to the monitor value 23, and the host device can send a corrected movement command 22 to the motor drive device 10 when the relative positional relationship is abnormal. Give or stop the alarm.

  With this configuration, in a motor control system that takes in the motor position from the motor position detector via serial communication and performs feedback control, the relative position is accurately estimated even when the external input signal transmission delay is large and the motor operates at high speed. can do.

(Example 2)
The second embodiment is an applied configuration of the present invention, and is provided with a parameter storage unit 17 for storing the relative delay correction amount calculated by the inter-input signal delay calculation unit 16. Since the parameter storage unit 17 is a non-volatile storage unit, it retains a value even when the power source of the motor driving device is reset. After resetting the power of the motor driving device, the detection position calculation means 13 can read out the relative delay correction amount from the parameter storage means 17 and can reuse it, and the recalculation of the relative delay correction amount can be omitted.

  This configuration eliminates the need for work (input signal wiring switching) performed during the relative delay correction amount calculation process, and improves usability. In addition, in the motor drive device 10 in which the parameter storage unit 17 has already been mounted for other uses, it is not necessary to add hardware, and an increase in cost can be suppressed.

  It is assumed that the motor control means 15, the detection position calculation means 13, and the inter-input signal delay calculation means 16 are processed by a microcomputer or the like.

  The motor driving device of the present invention is also useful for a printing machine or the like in which the relative positional accuracy between the print object and the print head is required.

DESCRIPTION OF SYMBOLS 10 Motor drive device 11 Internal counter 12 Counter memory | storage means 13 Detection position calculating means 14 Motor position taking-in means 15 Motor control means 16 Input signal delay calculating means 17 Parameter memory means

Claims (2)

Motor control means for generating a motor position latch signal at a constant period;
Motor position fetching means for fetching and storing a position counter value in the motor position detector through serial communication means at the input timing of the motor position latch signal;
Counter storage means for storing the value of the internal counter at the input timing of each signal of the motor position latch signal and two external input signals (first external input signal and second external input signal);
A detection position calculating means for estimating a motor position change amount from the motor position latch until the external input signal is turned on and calculating a motor position at an input timing of the external input signal;
The difference between the first internal counter value taken in by transmission of the first external input signal and the second internal counter value taken in by transmission of the second external input signal when the two external input signals are simultaneously turned on is calculated and relative Provided with a delay calculation means between input signals to be stored as a delay correction amount,
The detection position calculation means calculates the motor position of the input timing of the second external input signal by a value obtained by subtracting the relative delay correction amount calculated by the inter-input signal delay calculation means from the second internal counter value. The motor drive device characterized by the above-mentioned.   Parameter storage means, which is a nonvolatile storage means for storing the relative delay correction amount calculated by the delay calculation means between input signals, is provided, and the detection position calculation means from the parameter storage means after the motor drive device is turned on again The motor driving apparatus according to claim 1, wherein recalculation of the relative delay correction amount is omitted by reading the relative delay correction amount.

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