JPH0792266A - Photoelectric control device and automatic setting method for optimal gain thereof - Google Patents

Abstract

PURPOSE: To provide a photoelectron controlling unit which has a high degree of freedom for operation, and is resistant to noise, and in which the operating margin can be automatically decided. CONSTITUTION: An electron system 60 is controlled by a microprocessor 62 having an input key pad 24, and transmits a pulse from an photo-transmitter 64. The reflected wave is detected by a phototransmitter 70, and is entered into a main variable gain part 74, and the output is divided into two, so that one of them is entered into a margin variable amplifier 84. This includes a multiple D/A convertor 86 and an amplifier 88, the output of the same is supplied to a margin comparing unit 94, to be compared with a reference signal from a reference voltage generator 92, and a margin signal SMAR is outputted. The other output is compared with the standard signal similarly, through an amplifier 80. and the main optical pulse detecting signal SDET is outputted. These signals are controlled by the microprocessor 62, and the operation margin value is specified, so that the main variable gain part 74 is automatically controlled to obtain the optimum gain.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photoelectron detector, and more particularly, it relates to a photoelectron control unit which emits a light pulse at time intervals and synchronously detects the return pulse.

[0002]

2. Description of the Related Art Conventionally, optoelectronic control units have been manufactured within a plurality of molds, and each of the molds was suitable for a specific type of application environment. Moreover, optoelectronic control units have not been designed to provide the operator with sufficient useful information about the latest settings and conditions during operation. As a result, the optoelectronic control unit does not have the flexibility to be used in different types of application environments, and it also provides information according to the application classification, such as the information that the operator uses to position the unit. We couldn't provide enough.

Despite some optoelectronic control units operating under microprocessor control, these units provide the operator with a wide range of operating settings that are particularly user-friendly and suitable for different application classes. It was not designed like that.

Moreover, many optoelectronic control units are prone to providing false signals due to electrical or optical noise occurring at the same frequency as the pulse repetition rate of the optoelectronic control unit itself. Such noise may be due to other optoelectronic control units in the vicinity,
It may simply be due to other machines with comparable operating frequencies. Nevertheless, when the noise is at the frequency of the pulse repetition rate, conventional pulse counting and sync detection techniques could not eliminate this noise problem.

In addition, many conventional optoelectronic control units cannot accurately measure the operating margin, and do not display the reliability display indicating the stability of the entire operation. In general, it has been difficult to determine operating margins due to the narrow voltage range over which most optoelectronic control units operate, and due to amplification saturation problems that occur when such voltage ranges are exceeded. In other words, no satisfactory system has been developed so that the optoelectronic control unit can accurately determine its own operating margin over a wide range.

Further, even if the operation margin can be measured, it is difficult to determine the operation stability of the optoelectronic control unit. The optoelectronic control unit may be affected by high noise levels in the operating environment that may reduce operational stability despite being at the level of operating margin.

[0007]

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an optoelectronic control unit having a user friendly operator interface.
Here, the user-friendly operator interface means that the operator can control the operation settings over a wide range in an easy-to-use and easy-to-understand manner so that the optoelectronic control unit can be applied to many different usage patterns. Say.

Another object of the present invention is to provide an optoelectronic control unit with a target capture system that is resistant to electrical and optical noise generated at the same frequency as the repetition rate of the optoelectronic control unit itself.

Still another object of the present invention is, as a function relating to the operating margin and noise, an optoelectronic control capable of accurately measuring its own operating margin over a wide range of signal levels and providing a reliable display of its operational stability. To provide a unit.

Yet another object of the present invention is to provide an optoelectronic control unit in which the pulse repetition rate and operating range can be selected by the operator through the use of a user friendly operator interface.

Still another object of the present invention is an optoelectronic control which is flexible in operation, feeds back useful information to the operator, has other reliability regarding operation, and can be manufactured at a reasonable cost. To provide a unit.

[0012]

SUMMARY OF THE INVENTION The present invention comprises an optoelectronic control unit suitable for outputting a light pulse at time intervals and synchronously detecting a return pulse. This optoelectronic control unit has a variable gain part to determine the operating margin, an operator interface with multiple functions to allow the operator to control the entire electronic system of the unit, and a background obstacle with frequency. Nevertheless, a special system configuration including a target capture system with special pulse timing features for reliable target capture and a system that displays operational stability in terms of operational margin and noise activity is provided. I have it.

This system configuration includes two signal paths, each of which captures and amplifies the output from the photodetectors of the system, a comparison for separately comparing signal levels on both signal paths with a common reference level. Including vessels. But,
The second signal path includes a variable gain section capable of adjusting a gain on the signal path, and the adjustment can take several values among different values. The operating margin is to adjust the gain on the second signal path until the comparator mounted on this path switches the state, and the gain value at the time of adjustment is set to the gain value of the operating first signal path. Determined by comparing. In the preferred embodiment, the variable gain section is mounted on a single path leading from the photodetector to two signal paths. This is to reduce or suppress the main gain value and increase the range of the determined operation margin. In addition, the preferred embodiment includes a system for automatically setting system sensitivity for optimal motion utilizing motion margin measurements under background and target conditions.

The operator interface includes a plurality of display icons, each associated with one or more control functions. These icons are displayed in connection with the selection and operation of control functions. The interface also includes a numerical display means for displaying the numerical value associated with the icon and for assisting in the selection of control parameters. Further, in the preferred embodiment, this numerical value display means also operates to display the operating margin. This operational margin is displayed as an aid to the mechanical positioning of the optoelectronic control unit. In addition, the operator interface allows the user to select one of the optical pulse repetition rates, which allows the speed of the unit, or conversely the detection range, to be automatically adjusted according to the requirements of the operating environment. Can be adjusted.

To help overcome the background noise problem, the light pulses output during the target capture process must follow a pseudo-random jitter element. Such a jitter factor changes the inter-optical pulse time between selected optical pulses. Varying the time between pulses immunizes against electrical and optical noise on the frequency of the normal pulse repetition rate. Jitter techniques are applied to various algorithms in which different patterns of reception of successive pulses establish the criteria for target detection. For example, if four consecutive return pulses should be received to indicate the presence of a target, the next (ie, second, third and third) transmitted after the first return pulse is detected. The (fourth) light pulse is delayed by the pseudo-random type element. This is to avoid noise generated at the regular pulse repetition rate frequency in accordance with the synchronization detection process.

The operational stability of this optoelectronic control unit is
Determined by optoelectronic operational margin measurements and background noise measurements, the operational stability index is generated as a function of these quantities.
In the preferred embodiment, the operating margin is generated using a dual path system structure, and noise is measured by counting the noise pulses generated during the interpulse period. The stability index is determined according to a fuzzy logic element function of operation margin and background noise, and is determined according to a fuzzy logic rule relating to photoelectric operation margin and stability against background noise. This fuzzy logic technique allows the operational stability index to reflect empirical facts.
A desirable indication of steady state can be provided that corresponds to experience in the real world.

[0017]

EXAMPLE Referring to FIG. In the figure, an optoelectronic control unit 10 includes an electric element and an optical element, and a set of lenses 1 for guiding an optical output and collecting an optical input.
It is shown as having a housing 12 on which 4, 16 are mounted. The optoelectronic control unit 10 includes the information display means 2
2 also includes an operator interface panel 20 having an input keypad 24.

Referring to FIG. Optoelectronic control unit 10
Has a structure for transmitting a light beam 30 of a light pulse output from the lens 14 and reaching the mirror 18. Mirror 18
Directs a light beam 32 of reflected light pulses onto lens 16 for synchronous detection of reflected light pulses by the electronic components of unit 10. The light beams 30 and 32 clearly define the light path between the optoelectronic control unit 10 and the mirror 18. When the target 34 to be detected passes between the optoelectronic control unit 10 and the mirror 18, this light path is blocked, and the optoelectronic control unit 10 detects the presence of the target 24 and detects the presence of the target. Is generated. However, it should be understood that the optoelectronic control unit 10 can operate in a variety of forms. Here, various formats include, in addition to the case of detecting the backward reflection as described above, for example, “transmitted light” detection or “close proximity scattering” detection of light reflected by a target to be detected. There is.

An operator interface panel 20 is shown in FIG. Operator interface panel 2
The numeral 0 includes a transflective TNFT liquid crystal display means 22 characterized by a three-digit numerical value display means 40 and twelve kinds of display icons 41 to 52. Display icons 41 to 52
Provides a visual interface for displaying control information. The display means 22 includes a light emitting diode (LED) for illuminating from behind. The keypad 24 includes three separate input keys 24a, 24b, 24 for up, down and input, respectively.
Including c. The display means 26 includes three separate LEDs 26.
a, 26b, 26c are included. The LED 26a is displayed when power is applied to the optoelectronic control unit 10,
The ED 26b is displayed when the optoelectronic control unit 10 is producing an output signal, and the ED 26b is that the optoelectronic stability index of the optoelectronic control unit 10 (detailed later with FIG. 14) is greater than a fixed threshold value. Sometimes displayed. The icons 41-52 operate in conjunction with the keys 24a-24c, which allow the operator to preselect many different control options associated with the optoelectronic control unit 10. The icons 41 to 52 and their associated operation functions and menu classifications are shown in the icon display list in Table 1.

[0020]

[Table 1]

The icons 41 to 52 and the operations associated with them during visual display during the execution mode and the program mode are shown in the icon operation list of Table 2.

[0022]

[Table 2]

Whenever the optoelectronic control unit 10 is in the "program mode", the icons 41-52 correspond to two levels of menu items after the input key 24c is first pressed. The upper level is SEN, LO / D when the arrow keys 24a and 24b are pressed.
O, LRN, HY, ON / DLY, OFF / DLY, O
PT, OPT, MAR icons 45, 41/42,
43,44,46 / 52,47 / 52,48 / 52,4
It circulates between 9,50. When the input key 24c is pressed, the function corresponding to the displayed icon is input to select a different type of mode or set parameters. Pressing the arrow keys 24a and 24b advances the menu system to the next or previous menu item, either leaving the set value or mode unchanged or with no value. On the other hand, when a specific function is achieved,
The menu system automatically advances to the next displayed menu item without any other settings.

More specifically, when the sensitivity setting function corresponding to the SEN icon 45 is input,
Numerical display means 40 operates to display the main gain level setting for the amplification system. This display is made on an arbitrarily defined scale of 1-250 for the amplification system associated with the pulse detection electronics of unit 10. The arrow keys 24a and 24b can also be used to manually set a new gain level for the pulse detection signal amplification system. The gain value displayed on the display means 40 is selected for use as a new gain level when the input key 24c is pressed again.

When the bright operation selection function or the dark operation selection function corresponding to the LO / DO icon 41 or 42 is input, the unit 10 switches between the conflicting modes each time the input key 24c is pressed. Done. If the optoelectronic control unit 10 is in the bright operating mode,
When the input key 24c is pressed, the dark operation mode is switched. On the contrary, when the optoelectronic control unit 10 is pressed in the dark operation mode with the input key 24c, the optoelectronic control unit 10 is switched to the bright operation mode. LO icon 4 each time the bright mode is selected
1 is displayed.

When the learning function corresponding to the LRN icon 43 is inputted, the optoelectronic control unit 10 "learns" both the "non-light" state and the "light" state, and then the pulse detection to obtain the optimum system sensitivity. Set the gain setting for the amplification system. This learning will be described in more detail with reference to FIG. It should be noted that the learning function is independent of the user's choice of light or dark motion. The optoelectronic control unit 10 must first be set to the "no light" state. At this time,
In the bright mode of operation, everything that is intended to be turned off is initially provided to the detector, and in the dark mode of operation everything that is intended to be turned on is first provided to the detector. At the end of the learning function, the optoelectronic control unit 10 returns to the execution mode with the numerical display of the operational margin and the display of the MAR icon 50. LRN icon 4
3 is displayed until the gain setting value is obtained by learning while the learning function is being manually changed according to the sensitivity setting function.

When the hysteresis function corresponding to the HY icon 44 is input, when the input key 24c is pressed, the system has a large hysteresis amount (for example, 20%) and a small hysteresis amount (for example, 5%).
Switch between. During the set value selection process, the numerical display means 40 is a symbol "h" that displays the targeted selection.
Display either "i" or "lo". When the smaller hysteresis amount is selected, the HY icon 4
4 is illuminated to indicate that the system is operating with a small hysteresis.

When the output time delay setting function corresponding to the DLY icon 52 is input, the display means 20 is displayed.
Is ON icon 46, OFF icon 47 or ON
When the S icon 48 is lit, it is selected at that time,
Or the form of the default delay,
Display (ON delay, OFF delay, or one shot). On the other hand, the numerical value display means 40 displays the setting of the delay time. The arrow keys 24a and 24b are the input keys 2
It is used to change the delay function selected by 4c. The arrow keys 24a and 24b then control the numerical display means 40 to sequentially repeat different amounts of delay time. The desired delay time value is selected by pressing the input key 24c. The delay time selection process according to this delay function is continued until all delay related items are executed or passed.

When the option function corresponding to the OPT icon 49 is inputted, the numerical value display means 40 indicates that the optical pulse repetition rate selected at that time or not is selected. The arrow keys 24a and 24b are used to control the numerical display means 40 so that different numerical values (1, 2 or 3) giving different repetition rates when the optoelectronic control unit 10 operates are displayed in sequence. The desired repetition rate can be selected by pressing the input key 24c.

It should be noted that the optoelectronic control unit 10 operates effectively in transmitting and detecting light pulses and in providing output signals, except when the learning and selecting functions are performed. is there. In addition, the optoelectronic control unit 10 automatically returns to the "run mode", and after 6 seconds of keypad inactivity, the MA
The R icon 50 is displayed. However, the inactive state for 6 seconds is required in addition to the inactive state in the learning function. The learning function is required to return the run mode to the long inactivity state of 45 seconds. Optoelectronic control unit 1
When 0 is in the execution mode together with the MAR icon 50 indicating that the margin determining function corresponding to the routine 200 of FIG. 10 is effective, the numerical value display means 40 sets the operation margin at that time to 0.2 to 96. Display on the scale up to. This operational margin allows the optoelectronic control unit 10 to be mechanically positioned in order to obtain an optimum detection result.

Reference is now made to FIG. The electronic system 60 of the optoelectronic control unit 10 of the present invention is a microprocessor system 6 for executing a software program that controls all the functions of the optoelectronic control unit 10.
Including 2. The system 60 also comprises an LED (light emitting diode) 64 which produces a temporally separated light pulse which is collimated by the lens 14 for output from the optoelectronic control unit 10. This light pulse is generated corresponding to the current pulse supplied from the current driver 66 to the LED 64. Current driver 66
Operates under the control of the microprocessor system 62. The light output by the light emitting diode 64 and returned to the optoelectronic control unit 10 is condensed by the lens 16, and thus the light is received by the photodiode 70 so as to be captured. Microprocessor system 62
Controls both the repetition rate and the current amplitude, resulting in a light pulse depending on the repetition rate selected by the operator. The repetition rate is selected according to the selection function corresponding to the OPT icon 49 with respect to the repetition rate shown in Table 3.

[0032]

[Table 3]

The repeat speed is determined by the control routine 17 of FIG.
It is controlled by setting a basic value for the re-plate counter used in 0. The control routine 170 controls the signal interval time of the pulse control signal supplied to the drive unit 66 on the line 65. The gain of driver 66 is regulated by controlling the signal on line 67 to control the pulse current value.
The peak current must be controlled in harmony with the pulse repetition rate or otherwise to avoid overloading the LED 64. The overload on the LED 64 is caused by a given duty cycle.
Is the result of the increased peak current at.
It should be noted that there is generally a trade-off between system response time and detection range. That is, as the repetition rate increases, the response time improves but the detection range narrows. The optoelectronic control unit 10
Give the user the flexibility to select the repetition rate that best suits the response time and detection range that the user requires. FIG. 5 shows graphs 71 and 73, which show pulse trains 75 and 77 at repetition rates 1 and 2, respectively. Pulse 75a ~
75c and 77a-77e have the same pulse duration, but pulses 77a-77e have a half amplitude and
It has twice the frequency of occurrence and half the period.

The photodiode 70 is connected to a fixed gain transimpedance amplifier 72. The amplifier 72 has a low input impedance and converts the current signal of the photodiode 70 into a voltage supplied to the main variable gain section 74. The main variable gain section 74 includes a multiplex D / A converter 76 that adjusts the gain according to a control signal from the microprocessor system 62, and a fixed gain amplifier 78 that further increases the signal gain amount. The output of the main variable gain section 74 is given to the fixed gain amplifier 80 via the first path A, and is also given to the margin variable gain section 84 via the second path B.

Fixed gain amplifier 80 provides its output to detection comparator 90. The detection comparator 90, under the control of the microprocessor system 62, compares the output amplitude of the amplifier 80 with the amplitude of the reference voltage provided by the reference voltage generator 92. The detection comparator 90 produces a main light pulse detection signal S _DET which is supplied to the microprocessor system 62 as an indicator of the reflected light received by the unit 10 in synchronization with the light pulse output by the LED 64.

The comparison voltage generator 92 is controlled by the microprocessor system 62 to provide four reference outputs. These four reference values define the size of the hysteresis selected by the operator according to the hysteresis setting function. The variable margin gain unit 84 includes a multiplex D / A converter 86 that adjusts the gain according to a control signal from the microprocessor system 62, and a fixed gain amplifier 88. The variable margin gain unit 84 supplies the output to the margin comparator 94. The margin comparator 94 compares the amplitude of the signal from the margin variable gain unit 84 with the reference voltage generator 9.
2 is compared with the amplitude of the reference signal supplied from the device 2. The margin comparator 94 provides the microprocessor system 62 with a margin signal S _MAR useful for determining the operating margin level.

Path A (Amplifier 80 and Detection Comparator 90
,), Path B (including margin variable gain section 84 and margin comparator 94), and main variable gain section 74 provide one configuration controlled by microprocessor 62 under software control. This configuration is for specifying an operation margin value over a wide range and then automatically setting the gain of the system (main variable gain unit 74) in order to obtain the optimum detection result. The operation of system 60 in determining the operating margin value and automatically setting the gain value is described in detail below in connection with FIGS. 11, 12 and 13. The system 60 also includes the electronic components associated with the LCD display means 22, the keypad 24 and the LED display means 26. The LCD display means 22 includes the icon,
In order to display the output from the microprocessor system 62 according to the numerical values and their associated functions, L
It is driven by the CD drive circuit 96. Keypad 24
Provides input to the microprocessor system 62 in harmony with the icons displayed by the LED display means 26 and their associated functions. The LED display means 26 displays the characteristics of the basic operation as described above, and provides the visual output from the microprocessor system 62.

Next, referring to FIG. Routine 100
Shows the highest level menu control related to the LCD display means 22, the icons 41-52 and the keypad 24, whereby the functions related to the icons 41 to 52 are for selecting the operation mode and parameter setting. Entered in. In the first step 102, the SEN icon 45
Is displayed, and the function related to this is ready for input. Then, the program 100 executes steps 104 and 10.
Since it has 6, 108, 110, 112, 114 and 116, the upper arrow key 24a is repeatedly pressed,
Alternatively (in reverse order), in response to repeatedly pressing the down arrow key 24b, the SEN icon 45,
LO / DO icons 41, 42, LRN icon 43,
The HY icon 44, the DLY icon 52, and the OPT icon 49 are continuously displayed, and the functions associated with them are ready for input. When each icon is displayed, the program follows the input key 2 according to step 118.
4c is pressed, and when the input key 24c is pressed, the related function is input according to step 120.

Referring to FIG. Since the program 130 has steps 132, 134, 136 and 138, the value displayed on the numerical value display means 40 is changed to step 132.
The amount is increased or decreased by a fixed amount corresponding to the up arrow key 24a in step 1 or the down arrow key 24b in step 136. At the same time, step 1 of program 130
By means of 40 and 142, display values which take various values are specified for the function execution in connection with the depression of the input key 24c.

Referring to FIG. Here, a pulse control and detection control routine 170 is shown, and this routine 170 controls the operation of the optoelectronic control unit 10 when transmitting an optical pulse and detecting a response pulse in synchronization therewith and when capturing a target. It controls the display. Regarding the first step 172,
The rate counter is set to a basic value, for example 500 or more, while the pulse counter is set to a value of zero. Then the program proceeds to step 174 where
Here, the value of the replate counter is decremented by 1 to provide the new replate value. Then, in step 176, the program asks if the replate counter is now zero. If the replate counter is not zero, the program returns to step 174 to decrement the replate counter again. If, on the contrary, the replate counter is then zero, the program proceeds to step 178 and outputs one light pulse. It should be noted here that if the replate counter function of steps 174 and 176 is implemented in hardware using a counter associated with the microprocessor of system 62, then no microprocessor time is wasted. .

Next, in step 180, the program inquires whether the response pulse of the reflected light is synchronously received within the transmission time. If a return light pulse has been received, the program proceeds to step 182 where the pulse counter value is incremented by 1 to provide a new pulse count value. Steps 184, 185 and 18
6 is a different pulse count value.
events) are operated in conjunction with each other to guide steps 194, 195 and 196, respectively. The selection of steps 194, 195 and 196 depends on the number of consecutive pulses counted. If one of the continuous pulses is received, the program moves to step 194.
If two consecutive pulses are received, the program goes to step 195. If three consecutive pulses are received, the program moves to step 196. Steps 194, 195 and 196 set the replate counter to three different values, thereby avoiding interference with nearby optoelectronic control units and devices with other frequencies. “Dwelling (d) between light pulses
"well)" intervals are controlled for "jitter".

In step 194, the replate counter is set by adding the value of the pseudo random code A smaller than the basic value to the basic value. Step 195
In, the re-plate counter is smaller than the basic value, and different pseudo random code B values are added and set. In step 196,
The replate counter is set by adding the sum of the pseudo random codes A and B to the nominal value. Step 19
Following 4, 195 and 196, the program returns to step 174 to execute the loop defined in steps 174 and 176. This loop determines the time interval between light pulses. Since the replate counter is set to different values in steps 194, 195 and 196, this loop including steps 174 and 176
Take different execution times. As a result, in step 178, light pulses will be transmitted at slightly different, but non-standardized intervals.

Upon receipt of the fourth and subsequent light pulse, the program proceeds to steps 184, 185 and 186.
After passing through, the process proceeds to step 188, the output according to the hysteresis setting value is performed, and the threshold value becomes low. afterwards,
In step 190, the replate counter is reset to the base value, while the pulse counter is set to a value of 3 to ensure that step 188 is reached each time more successive pulses are received.

When returning to step 180, if no return light pulse is received, the program proceeds to step 160 and the replate counter is set to the base value again,
The pulse counter is set to zero. Then, in step 162, the output is turned off (if the output is on) and the detection threshold is reset (if the detection threshold is low) according to the hysteresis setting. After step 162, the program proceeds to step 1
Return to 74. This is to perform another standard "dwelling" interval and to send another light pulse according to step 178. Routine 170 only after receiving a return of light pulses that are repeatedly and continuously output,
The output of the optoelectronic control unit 10 is controlled so that the target can be captured. In addition, the routine 170 shifts the spacing between light pulses according to a plurality of random codes.
The random code is set to have different values for different control units installed in one factory. It does so to provide different jitter components, which help ensure that nearby optoelectronic control units do not interfere with each other.

FIG. 6 shows a graph of pulse train 163 during successful capture of a target over four consecutive pulses. The pulse 165b has a delay time due to the jitter element 167a of the random code A. The pulse 165c has a delay time due to the jitter element 167b of the random code B. The pulse 165d has a delay time due to the jitter element 167c of the random code A + B.
The time delay elements 167a-c provide an aperiodic timing format, which outputs pulses with close repetition rates when the unit 10 uses synchronous detection techniques. It avoids interference from other optoelectronic control units installed nearby and other sources of frequency noise.

Referring to FIG. Operation allowance routine 20
0 operates to detect the operational margin of the optoelectronic control unit 10. The detection of the operation margin is performed by adjusting the gains of the variable gain units 74 and 84 and using the output of the margin comparator 94. Step 20 of this program
In 2, it is asked whether or not the target object aimed at by the optoelectronic control unit 10 has been detected, and the branch here is determined depending on the result. Whether or not the target is detected is indicated by the output S _DET of the detection comparator 90.

If no target is detected, the gain of the variable margin gain section 84 ("margin gain") is set to 3 according to step 204. The gain is set by adjusting the amount of attenuation of the multiplex D / A converter 86. The program then proceeds to step 206, where the gain of the variable gain section 84 is increased by an amount that varies according to the gain value. Since this amount gives a linear scale to the operation margin value of 1 or less, it changes according to the gain value as shown in the gain / margin table shown in Table 4.

[0048]

[Table 4]

In step 208, the program asks if the margin comparator 94 is on. Whether it is in the ON state or not is indicated by the output signal S _MAR . If the margin comparator 94 is in the ON state (the output signal S _MAR is low level), the program proceeds to step 210, where the current value of the margin gain is used as an index for checking the value of the operation margin. . The program ends according to block 21.

On the other hand, if the margin comparator 94 is not on, the program asks whether the margin gain is at a maximum value to determine the branch there according to step 214. If the gain of the variable margin gain unit 84 is not the maximum value, the program returns to step 206. On the other hand, if the gain of the variable margin gain unit 84 is the maximum value, the program
In step 216, the operation allowance value is set to zero, and block 2
Terminate according to 18. Steps 206, 208 and 214 form a loop by means of repeatedly increasing the margin gain until the margin comparator 94 switches to the ON state. The gain value of the variable margin gain section 84 required to switch the margin comparator 94 to the ON state provides a criterion for determining the operational margin of the optoelectronic control unit 10.

Here, the process returns to step 202. If a target is detected, the program proceeds to steps 220 and 2
Proceed to 22. Here, the "suppression element" counter is set to zero and the margin gain is set to 3 by adjusting the attenuation amount of the multiplex D / A converter 86. The suppression element is the main variable gain unit 7
4, which is related to the gain value of 4 (main gain), and the main variable gain unit 74 can be adjusted in 5 steps according to step 238. The 5 steps are shown in the suppression margin table of Table 5. ing.

[0052]

[Table 5]

Thereafter, the program proceeds to step 224, where the gain of the allowance variable gain section 84 is decreased by a certain amount which changes according to the gain value. This reduction is done to provide a non-linear scale, as shown in the gain and margin table (Table 4) above. In step 226, the program asks if the margin comparator 94 is off. Whether it is in the off state or not is indicated by the output signal S _MAR . If the margin comparator 94 is off (the output signal S _MAR is high level), the program proceeds to step 228, where the current value of the margin gain and the current time of the suppression element are examined to check the operating margin value. The value of is used. The program then ends according to block 230.

On the contrary, if the margin comparator 94 is on, the program asks whether the margin gain value is 1/2 (ie, 0.5). This is a saturated system 6
This is done so that the gain does not decrease to a level that affects the amplifier circuit of 0. If the margin gain value is not 1/2 (ie, 0.5), the program returns to step 224 and the margin gain is reduced again. On the contrary, if the margin gain has been halved, the program proceeds to step 234 to increase the suppression factor in relation to different levels of main gain. Then step 2
At 36, the program asks if the suppressor value is 5 for a branch decision. If the suppression factor is not 5, the program proceeds to step 238, and the gain of the main variable gain section 74 is reduced to 1/2 of the value at that time by adjusting the attenuation amount of the multiplex D / A converter 76. The program then returns to step 222 and subsequent steps to adjust the gain level of the margin variable gain section 84. This adjustment is made in three steps related to the last three on-gain steps in the gain and margin table in an attempt to turn off margin comparator 94 again. However, if it is determined in step 236 that the suppression factor is equal to 5, the program sets the motion allowance value in step 24.
Set to a maximum value of 0 and terminate according to step 242.

Steps 234, 236 and 238 include
A first loop is provided to reduce the main gain of the system 60, which is done in five steps to avoid the effects of saturation affecting the amplification circuitry of the system.
On the other hand, steps 222, 224, 226 and 232
Repeats until the margin comparator 94 turns off and provides a second loop for reducing the margin gain. The main gain level (or suppression factor) and the margin gain are used as indexes for obtaining the value of the operation margin of the optoelectronic control unit 10.

Referring to FIG. The automatic gain setting routine 300 provides a learning function corresponding to the LRN icon, and in order to ensure reliable target detection, the optoelectronic control unit 10 observes the background situation, the target situation, and, Determine the optimum main gain setting for system 60. In step 302, the LO code is displayed.
Then, in step 304, the program queries whether the input key 24c has been pressed. This asks whether the optoelectronic control unit 10 has been properly set up to perform the background learning routine. Routine 306 is shown in FIG.
It is for adjusting the main gain of the optoelectronic control unit 10 in order to achieve an operating margin of less than three. This will be described in detail later. The program then proceeds to step 308 and the IH code is displayed. Then, in step 310, the program queries whether the input key 24c has been pressed. This asks whether the optoelectronic control unit 10 has been correctly set to the execution state of the target learning routine 312. Routine 312
Is shown in FIG. 13 and adjusts the main gain of system 60 to provide the optimum setting in the target situation. The program proceeds to step 314, the operation allowance is displayed on the numerical display means 40, the allowance icon 38 is lit according to the normal execution mode operation condition, and the routine 300 is executed.
Ends according to block 316.

Referring to FIG. Background learning routine 30
6 begins with the optoelectronic control unit tuned for background observation indicated by step 320. Next, according to step 322, the main gain (of the variable gain section 74) is set to one half of the maximum level by adjusting the attenuation amount of the D / A converter 76. The program further proceeds to step 324, counts the motion allowance according to the routine 200, and inquires whether the motion allowance is larger than 0.3 for the branch judgment. If the operating margin is greater than 0.3, the program proceeds to step 323 and the main gain is 1
(Counter) Only steps are lowered. The program further proceeds to step 325, counts new motion margins according to routine 200, and further determines the branch.
Ask if the operational margin is less than 0.3. If the operating margin is not less than 0.3, the program proceeds to step 328. In step 328, the program asks if the main gain is still greater than the default minimum required for proper operation of optoelectronic control unit 10. If the main gain is greater than the dead minimum, the program returns to step 323, else this routine 306 returns to block 3
Terminate at 30. Returning to step 325, if the operating margin is less than 0.3, the program proceeds to block 3
At 32, the routine 306 is exited and the routine 300 proceeds to step 308.

Returning to step 324, if the operating margin is not greater than 0.3, the program proceeds to step 32.
The main gain is set to the maximum level by advancing to 1 and adjusting the attenuation amount of the D / A converter 76. Next, the program proceeds to step 327, counts the new motion margin according to the routine 200, and the value is 0.3 for branch judgment.
Ask if it is less than. If the operating margin is 0.
If it is not less than 3, the program proceeds to step 326, the main gain is reduced by one (counter) step, and then returns to step 327. If, on the contrary, the operating margin is less than 0.3, the program exits routine 306 at block 332 and routine 3
00 to step 308. Background learning routine 3
06 is to repeatedly lower the main gain from its maximum level until the operational margin is less than 0.3 under background conditions.

Referring to FIG. Target learning routine 31
2 begins with the optoelectronic control unit tuned for target observation indicated by step 340. In step 342, the program calculates the motion allowance and asks if the motion allowance is greater than 2.0. if,
If the operating margin is greater than 2.0, then the detection operation is satisfied and the program transitions out of this routine 312 at block 344, step 31.
At 4 the routine 300 is re-entered. If the operation margin is 2.
If it is less than 0, the program proceeds to step 346 and asks if the operational margin is less than 0.6. If the operating margin is less than 0.6, it is not possible to obtain sufficient operating margin to satisfy the control operation, so the program blocks the routine 300 to terminate the routine 300.
Go to 8. If, on the other hand, the operating margin is not less than 0.6, the program proceeds to step 350 and asks if the operating margin is less than 2.0 and greater than 0.6. If the operating margin is not between 0.6 and 2.0, then the program goes to exit block 348 again because an error has occurred in the counting for routines 300, 306 and 312. If, on the contrary, the operating margin is a value between 0.6 and 2.0, the program proceeds to step 352 and increases the main gain by one step. Then, in step 354, the program queries whether the operational margin is equal to 2.0. If the operating margin is not 2.0, the program proceeds to step 356 and asks if the main gain is at the maximum level. If the main gain is not at the maximum level, the program returns to step 352 to increase the gain by one more step. If, on the contrary, the main gain has reached the maximum level, the program proceeds to block 348 to end the automatic gain setting routine 300. Returning to step 354,
If the operating margin is equal to 2.0, the program proceeds to step 360 and calculates the ideal gain setting for these conditions according to Equation 1 below.

Ideal sensitivity (optimal gain setting value) = (2 × gain value 1 × gain value 2) / ((2 × gain value 3) + (off margin × gain value 1)) (1) where: Value 1 = 2.0 maximum in "target learning" routine
Gain required to obtain ON operation margin of, OFF margin = minimum OFF operation margin value measured in "background learning" routine, gain value 3 = OFF operation margin value of 0.3 in "background learning" routine Is the gain, when is generated.

The main gain is then adjusted by proportionately reducing the digital control input to the D / A converter 76.

The program then exits routine 312 at block 362 and routine 3 at step 314.
Return to 00. Routine 312 can be used in different operating situations because the main gain is optimized in terms of the target situation and when the light / dark difference is small (eg, the operating margin is between 0.6 and 2.0). It is provided to set the optimum value of the main gain of.

Referring to FIG. The present invention also provides a display function of the stability of photoelectric conversion operation based on fuzzy logic technology. This display is based on the operation of routine 400.
The routine 400, which is performed via the ED display means 26, is executed in the background and provides information about the operating environment in which the optoelectronic control unit 10 is available. In step 402, the program executes a margin routine 200 to determine the motion margin. The program then proceeds to step 404
The level of optical or electrical noise is detected by counting the number of noise pulses that pass through the detection comparator 90 during the interpulse period. The interpulse period is, for example,
The time interval when no optical pulse signal is output and no return pulse is received. The number of noise pulses that activate the comparator 90 during the inter-pulse period provides a measure of the noise in its environment, yet that measurement is previously obtained by the electronic system 60 without interfering with other operations. It is a thing. The program uses the motion margin and the noise level value to derive the motion stability index using the look-up table in step 406. In step 408, the program compares the stability index obtained from the look-up table with the current threshold value (eg, 2.0), and if the motion index is greater than the threshold value, turns on the LED 26c.

The motion index look-up table is generated in accordance with the well-known fuzzy logic technique, and is given the belonging function and rule described later. Each belonging function for operation margin, noise, and stability is defined according to the fuzzy logic function list shown below.

[0065]

[Table 6]

Seven affiliation functions (membership
functions) are defined for operating margins, while three belonging functions are defined for noise,
Four affiliation functions are defined for stability. Numerical values in the fuzzy logic table are 0 to 5 when there is a motion margin.
From 0 to 15 for noise, and from 15 to 109 for stability. The four normalized numbers represent a trapezoid (or triangle) that defines the degree of belonging of each function.
The number in the first column (under "0 Start" in the table) indicates the point at which the affiliation function first starts increasing from 0 (0% certainty of affiliation). The number in the second column (under "1.0 up" in the table) corresponds to the point at which the affiliation function first obtains a value of 1.0, linearly above 0. ("1.
The number in the third column (under "0 down") is that the affiliated function first
Indicates the point where the value starts to decrease. The number in the fourth column (under "0 Stops" in the table) indicates the point where the value of the affiliated function reached 0 after linearly decreasing from 1. The values of affiliation functions are compounded according to the conventional weighted average technique, and
It follows the fuzzy logic rules shown in.

[0067]

[Table 7]

The affiliation function and its rule determine registration in the lookup table, as shown in the three-dimensional graph of FIG. The look-up table is associated with some discrete values for noise against motion margin and stability index. The stability index is related to the degree of accuracy required. These stability indices are used to provide a visual display or, alternatively, are output as analog signals from the optoelectronic control unit 10 so that the operational status of the optoelectronic control unit 10 can be displayed remotely.

While a particular embodiment of the invention has been shown and described, it goes without saying that the embodiment can be altered and modified without departing from the spirit and essence of the invention. It is believed that the appended claims include all such changes and modifications.

[0070]

As described above, according to the optoelectronic control unit of the present invention, the optoelectronic control unit can be applied to a large number of different usage forms, and the operation setting can be widened by a method easy to use and easy to understand. Operator control over the range. Further, the optoelectronic control unit of the present invention is resistant to electrical noise and optical noise generated at the same frequency as its own repetition rate. Furthermore, as a function related to the operation margin and noise, the own operation margin can be accurately measured over a wide range of signal levels, and reliable display of the operation stability can be performed.

[Brief description of drawings]

FIG. 1 is a perspective view from above of an optoelectronic control unit showing an operator interface on the top of the unit.

FIG. 2 is a block diagram showing the operation of the optoelectronic control unit in the back reflection mode.

FIG. 3 is a plan view showing an operator interface of the present invention used in an optoelectronic control unit.

FIG. 4 is a block diagram of an electronic system for use in an optoelectronic control unit according to the principles of the present invention.

FIG. 5 is a pair of graphs illustrating different pulse repetition rates selected for operation of an optoelectronic control unit according to the principles of the present invention.

FIG. 6 is a graph showing how pseudo random jitter affects pulse timing in accordance with the principles of the present invention.

FIG. 7 is a flowchart showing a function selection process related to the operator interface of the present invention.

FIG. 8 is a flowchart showing a variable setting process related to the operator interface of the present invention.

FIG. 9 is a flow chart illustrating a target capture process according to the principles of the present invention, where jitter is used to vary the spacing between pulses.

FIG. 10 is a flow chart showing a process for determining an operational margin in the context of the dual path structure of the present invention.

FIG. 11 is a flowchart illustrating a process for automatically determining a gain setting for an optoelectronic control unit in accordance with the principles of the present invention.

FIG. 12 is a flowchart showing a process used in an automatic gain setting routine of the present invention, which is a process of determining an operation margin in a background situation.

FIG. 13 is a flowchart showing a process used in an automatic gain setting routine of the present invention, which is a process of determining an operation margin under a target situation.

FIG. 14 is a flowchart showing a process of determining a motion stability index according to the principles of the present invention.

FIG. 15 is a three-dimensional mesh graph showing the stability of photoelectric conversion operation as a function of operational margin and background noise according to fuzzy logic techniques.

[Explanation of symbols]

10 ... Photoelectric control unit, 14, 16 ... Lens, 18
... mirror, 20 ... operator interface panel, 22 ... information display means, 24 ... input keypad, 26 ... display means,
40 ... 3-digit numerical value display means, 41-52 ... Icon, 60
… Electronic system, 62… Microprocessor system,
64 ... LED, 66 ... Current drive section, 70 ... Light emitting diode, 74 ... Main variable gain amplification section, 76, 86 ... Multiplex D / A
Converter, 78, 80, 88 ... Amplifier, 84 ... Margin variable gain amplification section, 90 ... Detection comparator, 92 ... Reference voltage generator,
94 ... Margin comparator.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Patrick Jay. Delaney Boston Post Road, Sudbury, 01776, Massachusetts, USA 206 (72) Inventor Philip E. Johnson, United States 01606 Massachusetts, Worcester, West Boilston Street 1137

Claims (23)

[Claims] 1. An optoelectronic control unit for detecting the presence of an object by outputting a light pulse in a delimited period and detecting a return light pulse in synchronization with this, and outputting a light pulse in a delimited period. And an electronic system for detecting a return light pulse in synchronism with the electronic system, and an operator interface for allowing an operator to control the electronic system and demonstrating its control function. System operating characteristics (operat
ional features) are standardized to include a microprocessor control system having a plurality of different control functions, the operator interface includes: a) the electronic system of the electronic system displayed in association with the selection and operation of the control functions. A plurality of display icons corresponding to each of the one or more control functions, and b) a numerical display means for displaying a numerical value in relation to the display of the icons according to the operation of the control function in the selection of control parameters. And c) an optoelectronic control unit comprising: a keypad for allowing an operator to input in association with the display of the icon for selecting the function and selecting a numerical value according to the function. 2. The optoelectronic control unit according to claim 1, wherein the numerical value display means also displays an operating margin value as an assisting element during mechanical alignment of the optoelectronic control unit. An optoelectronic control unit that operates. 3. The optoelectronic control unit according to claim 2, wherein the plurality of icons and control functions associated therewith are: a) a first icon for displaying a feature of motion margin determination and a motion margin determination function; and b) time. A second icon for displaying delay characteristics and a function for setting an output time delay, and c) Third and fourth icons respectively displaying characteristics of light environment operation and dark environment operation, and light environment mode or dark. An optoelectronic control unit that includes a function to select the environmental mode. 4. The optoelectronic control unit according to claim 3, wherein the plurality of icons and control functions associated therewith are: d) a fifth icon for displaying characteristics of pulse repetition rate; and a pulse repetition rate selection function, and E) An optoelectronic control unit including a sixth icon for displaying the characteristics of hysteresis selection and a hysteresis selection function. 5. An optoelectronic control unit for detecting the presence of an object by outputting a light pulse in a delimited period and detecting a return light pulse in synchronization with this, wherein: a) the photodetector. Comparing the amplitude value of the output from the with the amplitude value of the fixed reference signal on the first signal path, b) the amplitude value of the output from the photodetector and the amplitude value of the fixed reference signal match. Changing the gain value on the second variable gain signal path to determine a specific gain value when performing, and c) examining the value of the operational margin of the optoelectronic control unit based on the specific gain value. An optoelectronic control unit having means for numerically displaying an operation margin value generated by the. 6. The optoelectronic control unit according to claim 5, wherein the step of displaying a numerical value of the operating margin is: d) The amplitude value of the output from the photodetector is on the second signal path. Optoelectronic control unit, further comprising: suppressing the gain affecting the output from the photodetector on both signal paths until it falls within a range corresponding to an amplitude value of a reference signal. 7. The optoelectronic control unit according to claim 5, wherein the step of changing the gain value in the process of numerically displaying the operating margin includes: adjusting the signal attenuation to the second signal path. An optoelectronic control unit including the step of varying a digital signal input and thereby varying a gain value for a multiple D / A converter disposed above. 8. The optoelectronic control unit according to claim 5, wherein the process for displaying the numerical value of the operating margin is controlled by a microprocessor system, and the microprocessor is software for changing a gain value. It operates under control and its gain value is changed by controlling the multiple A / D converter and by tracking the output of a comparator arranged on the signal path. The tracking is performed by comparing a signal amplitude value on the path with an amplitude value of the reference signal and checking the operation margin value from a look-up table based on the specific gain value. 9. An optoelectronic control unit for detecting the presence of an object, said unit being suitable for allowing an operator to select a different light pulse repetition rate, the light pulses being generated in a time-delimited manner. Means, an operator interface means for allowing the operator to select one of a plurality of different optical pulse repetition rate settings, and the operator interface means corresponding to the plurality of repetition rate settings selected by the operator. An optoelectronic control unit comprising: means for controlling the repetition rate of the light pulse; and current value control means for the pulse generation means as a function of setting the repetition rate selected by the operator. 10. The optoelectronic control unit according to claim 9, wherein the light generating means comprises a light emitting diode. 11. The optoelectronic control unit according to claim 9, wherein the operator interface means shows an icon display portion displayed when a repetition rate is selected and a setting of the selected repetition rate. Optoelectronic control unit including numerical display. 12. A microprocessor control unit, a light source connected to the control unit to generate a light pulse, and arranged to detect a return light pulse generated from the light source, and outputting a light detection output signal. And a first variable gain amplifier for amplifying the output signal from the photodetector according to a gain setting value provided by the control unit to generate a main output signal, A second variable gain amplifier for amplifying the main output signal from the first variable gain amplifier according to a gain setting value given by the control unit to generate a margin output signal; Comparing means for comparing the main output signal from the first variable gain amplifier and the margin output signal from the second variable gain amplifier with a common basic level, respectively.
The comparison is made to generate two comparison signals for feeding to the control unit, the generation of the comparison signal being based on two gain values provided by the control unit for the two amplifier sections. Optoelectronic control unit comprising: comparator means for enabling the microprocessor control unit to determine an operating margin level. 13. The optoelectronic control unit according to claim 12, wherein each of the first variable gain amplifying unit and the second variable gain amplifying unit is a fixed amplifier, and the microprocessor is used to adjust a gain level. An optoelectronic control unit, comprising: a multiple D / A converter as an attenuator that operates under the control of the control unit. 14. The optoelectronic control unit according to claim 12, wherein the microprocessor control unit includes a storage unit having a software program therein, and the software program operates a gain setting of the variable gain amplification unit. And an optoelectronic control unit for determining an operating margin by using a comparison signal to identify the resulting output level. 15. The optoelectronic control unit according to claim 12, wherein the light source comprises a light emitting diode and the photodetector comprises a photodiode. 16. A light source that produces a light pulse directed across a target area where a target will be present, and a return light pulse from the target area is detected to target the target area. And a photodetector that outputs a photodetection output signal that indicates the presence or absence of the pulse that indicates the presence or absence of the pulse, amplifies the output signal from the photodetector, and compares this signal with a reference level And a second variable gain amplification path for amplifying the output signal from the photodetector and comparing this signal with a reference level to generate a margin level specifying signal. An optoelectronic control unit comprising: control means for changing the gain of the second variable gain amplification path and tracking the pulse detection signal and the margin level specifying signal to determine an operation margin. 17. The optoelectronic control unit according to claim 16, further comprising a main variable gain section for amplifying the photodetector output signal before being supplied to the first and second paths, the control means. Is suitable for changing the gain of the main variable gain section, whereby each gain level of the two paths can be suppressed. 18. The optoelectronic control unit according to claim 16, wherein the second variable gain amplification path is a first attenuator placed under the control of the control means to change the gain, and a first fixed. An optoelectronic control unit comprising a gain amplifier and a comparator for comparing an output signal from the first fixed gain amplifier with a reference level. 19. The optoelectronic control unit according to claim 18, wherein the attenuator comprises a multiplex D / A converter and the control means comprises a microprocessor system operating under software control. And optoelectronic control unit. 20. A light pulse from a light source is temporally delimited to generate a detection signal that is amplified by a variable gain amplifier and used to provide an indication of the presence or absence of a target in a target area. It is output so that it crosses the target range,
In an optoelectronic control unit in which synchronous detection is performed by a photodetector, a process of generating a first detection signal using the optoelectronic control unit under a background situation and an operation margin value of the optoelectronic control unit are fixed off margin threshold Value (fixedOFF margin thres
hold) to reduce the gain of the amplification unit, and a fixed ON margin threshold for the initial operation margin value of the system under the target condition.
and a step of setting the gain setting value to a current gain value of the amplifying section if the initial operation margin value exceeds the on-margin threshold value. A method of automatically setting the optimum gain setting value of. 21. The optimum gain automatic setting method for an optoelectronic control unit according to claim 20, wherein if the initial operation margin value of the system does not exceed the ON margin threshold value, the operation margin of the system is A step of increasing the gain of the amplification section until reaching an on-margin threshold; and, based on the gain of the amplification system when reaching the off-margin threshold, and when reaching the on-margin threshold. And a step of setting the gain setting value to an optimum value. 22. The optimum gain automatic setting method for an optoelectronic control unit according to claim 21, wherein the optimum value is the following formula: optimum gain setting value = (2 × gain value 1 × gain value 3) / ((2
× gain value 3) + (off margin × gain value 1)) where gain value 1 = (maximum on-operation margin is 2.0 under the target situation)
Gain required to be: OFF margin = (minimum OFF margin value measured during background situation) Gain value 3 = (OFF margin value of 0.3 was generated under background situation) The automatic gain automatic setting method is characterized by being calculated according to 23. The optimum gain automatic setting method for an optoelectronic control unit according to claim 20, wherein the step of increasing and decreasing the gain controls the attenuation provided by one or more multiple D / A converters. An automatic gain automatic setting method characterized by being achieved by the following.