| 摘要 |
1. Apparatus for determination, using the correlation method, of the going-past rate, of a lengthwise product, said apparatus including : - two sensors (1 and 2) offset in space in the direction the product (3) is moving, - a first delay-controlled correlation device (14) with a dual input, the said inputs being respectively connected to sensors (1 and 2), said first correlation device calculating two offset values of the correlation function of two signals incoming at both inputs of said first correlation device and comprising successively : a shift register (8) with two outputs offset with one another, a dual multiplier stage (10), a dual integrating stage (11) and a differential amplification stage (12), the said delay being controlled, through a first voltage period converter (9) to an error signal generated by a first adder (13) of which a first input is connected to the output of the differential-amplification stage (12) and a second output receives a set value (Vo), representative of the initial goingpast rate of the product, and - an indicator (15) showing the going-past rate of the product and the input of which may be connected to the output of the first converter (9), apparatus in which each sensor (1, 2) is connected to the first correlation device (14) through a shaping unit, said unit comprising successively a high-pass filter (4) and a comparator and characterized in that a low-pass filter (5) is located between the high-pass filter (4) and the comparator (7), in that said apparatus also includes a second delay-controlled correlation device (14') comprising the same components (8', 10', 11' and 12') arranged in the same way as the first correlation device (14) the delay of which is also controlled, through a second voltageperiod converter (9'), to an error signal generated by a second adder (13') of which the first input is connected in the same way as the first input of the first adder (13) and the second input of which is connected to the output of the first adder (13), both inputs of the second correlation device (14') being connected to the output of the high-pass filters (4) through comparators (7') and in that the input of the indicator (15), denoting the speed of the product, may be connected to the output of the second converter (9'). |
