JPH0524010Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> This invention uses a scanning head that is reciprocated in a direction orthogonal to the running direction of a sheet-like traveling object such as paper or film to determine the basis weight, thickness, etc. of the traveling sheet. The present invention relates to an improvement in the controllability of stop/reversal position control of a scanning head in an apparatus for measuring the profile of a scanning head.

<Industrial Application Field> The general configuration of a profile measuring device will be explained based on FIG. 1 is a sheet-like traveling body that is fed from the back of the paper toward the front; 2 is a head support frame fixed so as to surround this traveling body;
Reference numerals 301 and 302 denote scanning heads which are arranged opposite to each other with the traveling body in between, and are supported by the support frame 2 and are reciprocally driven by the head traveling mechanism 4 in a direction perpendicular to the traveling direction of the traveling body 1 (in the direction of arrows A and A'). be done.

In the scanning head, for example, a reference radiation source is provided on the 301 side, the amount of attenuation of the radiation R is measured by the sensor on the 302 side, and the measured value PV is processed by the arithmetic unit 5 to measure the basis weight and thickness of the traveling object. It is possible to determine the value e _pf .

6 is a pulse generator that generates a clock pulse CP that regulates the separation of profile data;
The clock pulse CP is the profile creation device 7.
and is supplied to the head travel control device 8. 10
1 is a man-machine device that receives profile data PF, and 11 is a profile control device.

Reference numeral 9 denotes a center detector for detecting the center position C of the scanning head, which is realized by a micro switch or the like, and its contact signal E _c is supplied to the profile creation device 7 and the head travel control device 8 .

The operations of the profile creation device 7 and head travel control device 8 will be explained with reference to FIG. The positional relationship between the clock pulse CP shown in A and the data buffer of the profile PF shown in B is not fixed.
When the head is scanned in the A direction, the timing when the detection signal E _c of the center position C point is received.
The profile measurement value e _pf at the timing t _o of the rising edge of the clock pulse CP that occurs first after t _c is written into the nth data buffer. Thereafter, the profile measurement values are sequentially written to the adjacent data buffer at each rising timing of CP.

On the other hand, the head travel control device 8 counts clock pulses from the timing _tc when it receives the center position signal _Ec , and transmits a stop/reverse operation signal MV to the head travel mechanism 4 when a predetermined count number m is reached. After stopping the head, start scanning in the opposite direction.

Regarding the profile data in the opposite direction, similarly, the measured values of the profile are sequentially written into the data buffer using the rising timing of the clock pulse, but the first rising timing t _o- after the timing t _c of point C is used. ₁ the measurement signal
e _pf ' is forcibly written to the (n-1)th data buffer.

If the stop/reversal position of the head is always at point d immediately after the rise of the clock pulse as shown in the figure during each reciprocation, the continuity of the buffer data PF will be maintained.

<Problems to be solved by the invention> However, in reality, it is difficult to regulate with high precision the positional relationship between the stop/reversal position of each reciprocating scan and the rising or falling point of the clock pulse due to the inertia of the bed. In a certain reciprocating cycle, as shown in FIG. 3, the clock pulse may be reversed at a point d immediately after the rising edge of the clock pulse, and in a certain reciprocating cycle, it may be reversed at a point d' immediately before the rising edge of the clock pulse.

Due to these variations in the reversal position, the contents of the data buffer when reversing at point d' will be shifted by one section compared to when reversing at point _d . If the configuration is such that the rising edge of the clock pulse is forcibly written into the (n-1)th data buffer, there is a problem that writing to the nth data buffer is lost, resulting in a loss of continuity in profile measurement.

The present invention aims to provide a profile measuring device that can solve these problems.

<Means for Solving the Problems> The structural feature of the present invention is that the profile measuring device measures the profile of the traveling body using a head that scans back and forth in a direction orthogonal to the traveling direction of the sheet-like traveling body. a pulse generator that transmits clock pulses of a constant period to regulate data division; and a head running control means that controls stop/reversal of the head based on the count of the clock pulses based on the scanning center position signal of the head. In a profile measuring device having a profile creation means for creating/updating profile data divided into a plurality of sections by inputting the measured value of the head, the clock pulse, and the center position signal, the head travel control means stops the head. /inversion timing is determined by adding a correction amount due to the inertia of the head to the count number of the clock pulses.

<Function> According to the present invention, in addition to the conventional number of pulses, a tuning constant that takes into account the inertia of the head is given to the timing of generating the stop/reverse operation signal, and the stop position of the head is set at approximately the center of the duty of the clock pulse. regulated by.

<Example> An example of the present invention will be described based on FIG.
Descriptions of components that are the same as those described in the prior art will be omitted, and descriptions of characteristic parts will be added.

The feature of the present invention is that in addition to the count number m of clock pulses that give the stop/reversal timing to the head travel control device 8, a tuning constant τ that takes into account the inertia of the head is provided, and the operation output MV for stop/reversal is generated. By delaying the timing by τ from the conventional timing, the stop position of the head is regulated to approximately the center of the duty of the clock pulse.

FIG. 4 is an explanatory diagram of the operation of the stop control of the present invention in comparison with the conventional stop control. Conventionally, in response to the clock pulse CP shown in A, the operation output MV is transmitted at the m-th pulse timing t _n from the timing signal t c at the center position as shown in _B , and the stop position of the head is determined by the clock pulse as shown in C. These are positions d and d' near the rising or falling edge of CP.

According to the present invention, as shown in B', the timing of the operation output MV is delayed by a certain amount due to the tuning constant τ, and therefore the stop position of the head is
As shown in C', the clock pulse CP is shifted to a position f, f' approximately at the center of the duty cycle.

The value of the tuning constant τ may be set empirically in consideration of the inertia of the head, etc., and may be adjusted so that stopping/reversal is performed at positions f and f'.

Furthermore, if the duty cycle of the clock pulse is constant at approximately 50%, the timing
It is also possible to calculate the correction time from t _n to t _n ′ so that the stop position is at the center of the duty.

In other words, as shown in FIG. 5, if you want to generate a manipulated output with clock pulse N and then stop it, first generate the manipulated output with clock pulse N-1 and then change the correction time τ continuously from 0. Find the time τ _N for detecting N. Furthermore, time τ _N+1 for detecting clock pulse N+1 is determined by continuously changing τ. From these, the correction time τ is determined by τ=τ _N +3(τ _N+1 +τ _N )/4.

<Effects of the invention> As explained above, according to the invention, it is possible to control the stop/reversal position of the scanning head to always be maintained at approximately the center of the clock pulse duty, which eliminates the need for conventional control devices that lack continuous control of profile data. This problem can be solved, and it becomes possible to measure the profile more accurately and improve the controllability of basis weight control and thickness control using this data.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram showing an embodiment of the present invention, Fig. 2 is an explanatory diagram of the operation of creating profile data, Fig. 3 is an explanatory diagram of the operation of creating profile data in the case of the conventional configuration, Figs. 4 and 5 FIG. 2 is an explanatory diagram of the operation of the stop control of the present invention. 1...Sheet-like traveling body, 2...Head support frame,
301, 302...Scanning head, 4...Head traveling mechanism, 5...Arithmetic unit, 6...Pulse generator,
7... Profile creation device, 8... Head travel control device, 9... Center detector, 10... Man-machine device, 11... Control device.

Claims (1)

[Scope of utility model registration request] A profile measuring device that measures the profile of the traveling body using a head that scans reciprocatingly in a direction orthogonal to the traveling direction of the sheet-like traveling body, comprising: a pulse generator that transmits a clock pulse of a constant period to regulate the separation of profile data; head running control means for controlling the stop/reversal of the head according to the count number of the clock pulses based on the scanning center position signal of the head; In a profile measuring device having a profile creation means for creating/renewing profile data divided into sections, the stop/reversal timing of the head by the head travel control means is adjusted by the amount of correction due to the inertia of the head based on the count number of the clock pulses. A profile measuring device characterized by determining the profile by adding.