JP3419032B2 - Laser ranging sensor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laser distance sensor capable of outputting a distance measurement value of a displacement amount of an object to be measured. [0002] Light is projected from an optical head onto an object to be measured, and
2. Description of the Related Art A laser ranging sensor that receives reflected light from a distance measurement target object and obtains a displacement amount of the distance measurement target object from a position of the received reflected light has been used. Since the laser distance measuring sensor obtains the displacement amount based on the position of the reflected light from the object to be measured, the distance measuring accuracy changes depending on the light reflectance of the object to be measured. For example, a distance measuring object having a high reflectance, such as a blank sheet, has a large amount of reflected light and a small amplification factor of a signal component. A signal with sufficient amplitude can be obtained for the noise. Conversely, a distance measurement target object with a low reflectance, such as black paper, has a small amount of reflected light, so if the amplification rate of the signal component is not increased, the noise of the circuit of the laser distance sensor will be reduced. A signal with sufficient amplitude cannot be obtained. [0006] Therefore, the laser distance measuring sensor is configured to be capable of measuring a distance even if there is a change in reflectance by switching a plurality of amplification factors. Here, there arises a problem that it is necessary to determine which amplification factor should be selected for a certain distance measurement target object to obtain the optimum amplification factor. To solve this problem, the laser ranging sensor has two modes: a manual mode in which the operator determines and determines the amplification factor, and a semi-auto mode in which the operator searches for the optimal amplification factor for the object to be measured at a certain point in time. There is an auto mode for automatically adjusting the amplification factor following a change in the reflectance of the object to be measured. In the semi-auto mode, the amount of light received is determined by the CPU in accordance with the amount of light received by the optical head at the stage of operation by the operator. In the auto mode, the CPU monitors the amount of received light for each distance measurement and sets the optimum amplification factor. [0006] The laser distance measuring sensor adjusts the amplification factor according to the reflectance of the object to be measured. Depending on the application, distance measurement is performed by changing the amplification mode and amplification rate. It is the CPU that calculates the distance measurement value. Since the laser ranging sensor performs high-speed ranging, C
The PU must perform high-speed operations. For this reason,
The routine for calculating the distance measurement value is a permanent loop, and cannot monitor the mode of the amplification factor or the like for each distance measurement. Therefore, when the operator changes the amplification mode or the amplification factor, the CPU is reset and the initialization routine is activated. Initialize the amplification mode and amplification rate inside the initialization routine. The conventional laser ranging sensor has one operation unit for one optical head. That is, when the operator operates the amplification mode and the amplification factor, the amplification mode and the amplification factor need only be initialized. Here, one CPU is provided for one optical head.
And a distance measuring sensor with an operation unit are disclosed in
As described in Japanese Patent No. 313532, there are many problems when distance measurement is performed using two optical heads. For this reason, one CP
A laser ranging sensor has been devised in which two optical heads are connected to the U and the operation unit, and each optical head is alternately measured. This laser distance measuring sensor has one CPU and one operation system for two optical heads.
When executing the initialization routine, the operation information transmitted from the operation unit to the CPU includes only information on the operation of one optical head, and includes information on the amplification mode and amplification factor for both the two optical heads. Insufficient information to make a decision. Therefore, the two optical heads are completely independent of the amplification mode and the amplification factor (even if the amplification mode and the amplification factor for one optical head are changed, the amplification mode and the amplification mode for the other optical head are changed). (A state in which the amplification rate is not affected). An object of the present invention is to provide a laser measuring system having two independent optical heads, a single CPU, and a single operation unit, having a completely independent amplification mode and amplification factor for the two optical heads. It is to provide a distance sensor. According to the present invention, a position signal is projected on an object to be measured, the reflected light from the object is detected, and the center of gravity of the received reflected light is detected. Two optical heads for outputting the signals, a signal amplifying unit for amplifying the position signal from each of these optical heads, an A / D converter for A / D converting the signal from the signal amplifying unit, and an A / D converter A CPU for determining an amplification factor of a signal amplifying unit or calculating a displacement position of an object to be measured based on a digitized ranging signal from a measuring device;
A CPU memory for storing U programs and data; and an operation unit for receiving an operation from outside and transmitting the operation content to the CPU as information, and amplifies an amplification factor determined by the CPU to a signal amplification unit. in Relais Za ranging sensor is configured to send a rate adjustment signal, when the external operation is made to one of the optical head, whereas
For the optical head, the amplification factor is determined according to the operation.
The amplification factor is used, and the CPU
Using the amplification factor determination method and the amplification factor of the previous operation and stored in the memory
To initialize the two optical heads and decide after initialization
Determination method and amplification for two optical heads
Control means for controlling the rate to be stored in the CPU memory is provided. According to the present invention, even if the amplification mode and amplification factor for two optical heads are initialized, the optical head which is not operated is initialized with the previous amplification mode and amplification factor. Therefore, it can be said that the two optical heads are independent, without being affected by changes in the amplification mode or amplification factor for the operated optical head. Embodiments of the present invention will be described below with reference to the drawings. Although the laser ranging sensor of the present invention has two optical heads, it has only one operation system, so that the amplification mode and amplification factor for the two optical heads are not simultaneously operated. For this reason, from the operation unit,
The information on the operation content sent to U is operation information on the amplification mode and the amplification factor of the optical head that can be operated at present. As for the amplification mode and amplification factor for the optical head that has not been operated, the CPU reads out data stored before the operation currently being performed and uses the data. The non-operated optical head is the information of the amplification mode and the amplification factor before the operation stored in the memory for CPU, and the operated optical head is the amplification mode and the amplification factor sent from the operation unit to the CPU. The two optical heads are initialized using the information of (1). After the initialization is completed, the amplification mode and amplification factor of each optical head are stored in the CPU memory. If the CPU operates in this manner, even if the amplification mode and amplification factor for the two optical heads are initialized, the optical head that is not operated is initialized with the previous amplification mode and amplification factor. It can be said that the two optical heads are independent without being affected by changes in the amplification mode or amplification factor for the operated optical head. The details will be described below. FIG. 1 is a system configuration diagram. Light is projected from the two optical heads 1 and 2 to the distance measurement target objects 3 and 4, and each of the optical heads 1 and 2 sends a distance measurement value signal to the signal amplifier 6. Optical heads 1 and 2 and signal amplifier 6
The signal amplifying unit 6 selects the optical heads 1 and 2 that receive the position signal by the changeover switch 5 located between the two. The signal amplifying section 6 amplifies the position signals obtained from the optical heads 1 and 2. There are 7 stages of amplification rate and C
In accordance with the amplification factor adjustment signal from the PU 8, the optical heads 1 and
2 is amplified. Since the position signal amplified by the signal amplifier 6 is an analog signal, the A / D converter 7
A / D conversion into digital data. The digitized position signal is passed to the CPU 8. The CPU 8 reads the digitized ranging signals and calculates the ranging values of the optical heads 1 and 2. Further, it determines an amplification factor corresponding to each of the optical heads 1 and 2 and outputs an amplification factor adjustment signal to the signal amplification unit 6. The CPU memory 9 stores the execution procedure of the CPU 8 and data. The operation unit 10 receives the operation of the operator.
Front panel key operation, RS-232C command,
The mode of amplification and the amplification factor can be controlled by the GPIB command and the parallel interface command. FIG. 2 is a flowchart showing the operation procedure of the embodiment of the present invention. First, the CPU 8 receives information from the operation unit 10. The CPU 8 resets the amplification mode and amplification factor information for the operating optical heads 1 and 2, the information about which optical head 1 or 2 is being operated, and the semi-auto mode. It receives semi-automatic information to know whether or not it has been performed (step S1). Next, the amplification mode and amplification factor information for the optical head 2 or 1 which is not the operation target is determined based on the information on which optical head 1 or 2 the operation is received from the operation unit 10. The CPU 8 reads from the CPU memory 9 (step S2). Next, the CPU 8 initializes the amplification mode and the amplification factor for the two optical heads 1 and 2 from all information obtained so far (step S3). Finally, the CPU 8 sets the amplification mode and amplification rate for the two optical heads 1 and 2 determined after initialization, such as the amplification rate determined by initialization of the semi-auto mode, to C
It is stored in the PU memory 9 (step S4). It is the CPU memory 9 that stores the execution procedure and data for the calculation. FIG. 3 is a diagram showing amplification factor data in each amplification mode. In FIG. 3, the two optical heads 1 and 2 are head1 and head2 for convenience. The numbers in FIG. 3 represent amplification factors. Since the amplification rate of the present embodiment is 7 stages, it is 0, 1,
2, 3, 4, 5, and 6. By the way, it is better to measure the distance as the amplification factor becomes higher as long as the signal processing circuit is not saturated. This is because the higher the amplification rate, the greater the value of the digitized position signal data and the smaller the displacement of the object to be measured with respect to a change per bit, even for the same amount of received light. In other words, the greater the amplification factor, the better the distance measurement resolution. As described above, according to the present invention, a light is projected onto an object to be measured, the light reflected from the object is received, the center of gravity of the received light is detected, and the position signal is detected. Two optical heads for outputting the signals, a signal amplifying unit for amplifying the position signal from each of these optical heads, an A / D converter for A / D converting the signal from the signal amplifying unit, and an A / D converter A CPU for determining an amplification factor of a signal amplifying unit or calculating a displacement position of an object to be measured based on a digitized ranging signal from a measuring device;
A memory for the CPU for storing the program and data, and an operation unit for receiving an operation from the outside and transmitting the operation content to the CPU as information. The amplification factor determined by the CPU is supplied to the signal amplification unit. in Relais Za ranging sensor is configured to send as an adjustment signal, when the external operation is made to one of the optical head, the one
For the optical head, the amplification factor determination method and increase
Use the width factor and write the CPU
Using the operation previous amplification factor determination method and amplification factor stored in Li
Initialize the two optical heads and determine after initialization.
Method and gain for two optical heads
The control means for controlling the optical head to store it in the CPU memory is provided, so that even if the amplification mode and amplification factor for the two optical heads are initialized, Since the head is initialized with the previous amplification mode and amplification factor, the two optical heads can be said to be independent, without being affected by changes in the amplification mode or amplification factor for the operated optical head. . Therefore, the operations of the two optical heads of the laser distance measuring sensor having two optical heads and having one signal processing section and an operation section can be made independent. As a result, this type of laser ranging sensor can function as two laser ranging sensors that process ranging signals from one optical head with one system of signal processing unit and operating unit.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a system configuration diagram of an embodiment of the present invention. FIG. 2 is a diagram showing an operation procedure of the above. FIG. 3 is a diagram showing data of an amplification factor in each amplification mode according to the first embodiment. [Description of Signs] 1 optical head 2 optical head 3 object to be measured 4 object to be measured 5 switch 6 signal amplifying unit 7 A / D converter 8 CPU 9 CPU memory 10 operation unit

Claims (1)

(57) [Claims 1] A light is projected on an object to be measured, a light reflected by the object is received, and a center of gravity of the received reflected light is detected.
Two optical heads for outputting a position signal, a signal amplifying unit for amplifying a position signal from each of these optical heads, and an A / D converter for A / D converting a signal from the signal amplifying unit. Vessel and A
Based on the digitized ranging signal from the / D converter,
A CPU that determines the amplification factor of the signal amplification unit and calculates the displacement of the object to be measured, a memory for the CPU for storing programs and data of the CPU, and accepts an external operation and operates the CPU. comprising an operation section for transmitting the content as the information, in Relais chromatography the <br/> over ranging sensor is configured to send as an amplification factor adjustment signal amplification factor to the signal amplification unit CPU determines, from the outside when the operation has been performed on one of the optical head, Misao for one optical head
The two optical heads are used for the other optical head by using the gain determination method and the gain before the operation stored in the memory for the CPU. Head
Initialize, two optical heads determined after initialization
The method for determining the amplification factor and the amplification factor are stored in the CPU memory.
A distance measuring sensor provided with control means for controlling the distance measurement.