JPH0587930A - Collision preventing apparatus - Google Patents

Abstract

PURPOSE:To make alignment of an optical axis easy and to remove outer disturbances by projecting a laser light to the other moving object, receiving the light reflected by a reflector, and measuring the distance between the moving objects from the phase difference of the projected light and the received reflecting light. CONSTITUTION:Two cranes A, B are set on a pair of rails 1 to be freely movable right and left. A wheel 2 is driven by a driving motor 3. An instruction from a remote controller 8 or 9 is transmitted to a controller 5 via an interface device 7, thereby controlling a transmitting/receiving part 4. A laser light is projected from a transmitting part 401 of the transmitting/receiving part 4 of the crane B towards a reflector 10 of the crane A. The reflecting light is received by a receiving part 402 of the crane B. The phase difference between the projected light and the reflected light is measured by the controller 5, so that the distance L between the cranes A and B is obtained. The distance L is compared with a set distance stored beforehand. If the distance L is within the set distance, the controller 5 instructs a driving circuit 6 to stop the motor 3, thereby making it possible to avoid a collision.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a collision preventing device for preventing collision of a plurality of cranes or hoists operating on the same rail.

[0002]

2. Description of the Related Art We often see scenes where heavy materials such as raw materials, products, and goods are transported by cranes and hoists in ironworks and warehouses. Cranes and hoists
Work is carried out by remote operation on rails installed on the ceiling. There are also large cranes that operate on rails laid on the ground. In any case, if the amount of work increases, multiple rails will be moved over the rails.
And hoists will operate. The plurality of cranes and the like do not move in the same direction at the same time, but move in the direction requested by the operator's intention, so that they may sometimes collide with each other. Therefore, these are equipped with devices that prevent collisions with each other.

A conventional collision prevention device has, for example, a first reflecting plate and a second reflecting plate provided in one lane, and the first reflecting plate in the other lane. A first sensor having a light emitting diode for emitting light toward the plate and a light receiving element for receiving the light reflected from the first reflecting plate; and emitting light for the second reflecting plate. A second sensor having a light emitting diode and a light receiving element for receiving the light reflected from the second reflecting plate, and the crane adjacent to the first sensor is in the distance measurable range. After confirming that the first sensor has both cranes within the distance measuring range, the distance between them is measured with the second sensor and the distance between them is determined. An alarm is issued when the set value is reached, and at the same time, the crane is stopped to an emergency to prevent a collision. Is configured urchin, such a device is described in JP-A-62-240296.

[0004]

The conventional device as described above is highly safe because it confirms the distance between the two cranes while confirming that both cranes are within the distance measuring range.
However, the configuration is complicated and the device is expensive, and since there are two sensors, alignment of the optical axis after installation is troublesome, and there is disturbance such as insertion of light from a flashlight or sunlight, or intrusion. It was vulnerable to temporary shading of animals such as birds, which could cause malfunctions.

The present invention is intended to improve the above-mentioned drawbacks, and an object of the present invention is to provide a collision preventing device capable of simplifying the optical axis alignment by using a single sensor system and removing disturbance. To do. Another object of the present invention is to obtain a collision prevention device that does not cause a malfunction even when the animal temporarily blocks light.

[0006]

In order to achieve the above-mentioned object of the present invention, the present invention uses a reflected light obtained by reflecting light emitted from one of the moving bodies by the other moving body between the moving bodies. In a collision prevention device for measuring an interval and generating an approach signal when the measured distance is within a predetermined value, a distance setting means for setting an approach distance of both moving bodies and a distance for storing the distance set by the distance setting means. The storage means, a calculation means for calculating the phase difference between the phase of the light emitted from one of the moving bodies and the phase of the reflected light, and the distance obtained from the phase difference calculated by the calculation means and the distance storage means are stored. It is an object of the present invention to provide a collision prevention device comprising: a signal generation unit that outputs a signal when the distance obtained by comparing the set distance with the calculation result of the calculation unit is within the set distance.

[0007]

The laser light is emitted to the other party, reflected by the reflector, the reflected light is received, the phase difference between the emitted light and the received reflected light is measured, and the distance between the moving objects is determined from the phase difference. Is calculated and an alarm is issued when the distance is within a set value.

[0008]

Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram of a crane to which a collision prevention device according to the present invention is applied, and in the figure, reference numeral 1 is two rails linearly laid on the ceiling of a warehouse or the like. Two cranes A and B are placed on the rail so that they can move left and right. Reference numeral 2 is a wheel provided on each crane and placed on the rail 1. An electric motor 3 for driving is connected to the wheel 2, and the cranes A and B can move by driving the electric motor 3. Reference numeral 4 denotes a light transmitting / receiving unit, and the light transmitting / receiving unit 4 is provided with a light transmitting unit 401 and a light receiving unit 402.
A light emitting element made of a laser and a semiconductor light receiving device are provided inside the light transmitting / receiving section 4, the details of which will be described later. Reference numeral 5 denotes a controller, which issues an operation command for the light transmitting / receiving unit 4 and processes an optical signal received by the controller,
The distance between the two cranes is measured and the signals for controlling the operation of the crane are created. The detailed configuration will be described later. 6
Is a high-power circuit 6 that receives a signal from the controller 5 and controls the electric motor 3. 7 is an interface device,
It is connected to the remote controller 8 by a conductive wire, transmits a command from the ground to the controller 5, and receives a signal from the remote controller 9 coupled by light. Reference numeral 10 denotes a reflector that reflects the light emitted from the light transmitting / receiving unit 4.

FIG. 2 is a block diagram showing details of the light transmitting / receiving unit 4 and the controller 5. A light transmitting unit 40 is provided in the light transmitting / receiving unit 4.
The laser light emitter 403 is placed at the focal position of 1.
This laser emitter 403 is 1.8M from the oscillator 404.
The light which is driven by the drive circuit 405 which amplifies the high frequency signal of Hz and continuously emits light is modulated by this high frequency signal. A semiconductor light receiving element 406 is placed at the focal position of the light receiving section 402. In addition, the transmitter / receiver 4 has
Another semiconductor light receiving element 407 is placed, and this semiconductor light receiving element 407 is spectrally separated from the laser light emitting body 403 and is a spectroscope 4 such as a half mirror or an optical fiber.
The reference light guided by 08 is received.

Next, the inside of the controller 5 will be described in detail. In FIG. 2, reference numeral 501 is a high frequency amplifier circuit, which converts the reference light received by the semiconductor light receiving element 407 into a high frequency electric signal and then amplifies it to a predetermined size. The high frequency variable amplifier circuit 502 is the semiconductor light receiving element 40.
After converting the reflected light received by 6 into a high-frequency electric signal, this is amplified to a predetermined size and the AGC described later is used.
The amplification factor is changed by the signal. High frequency amplifier circuit 50
The respective signals amplified by 1 and 502 are mixed circuits 50.
4, 505 is input. 503 is a local oscillator,
The local oscillation signal transmitted here is generated by the two mixing circuits 50.
4 and 505, frequency mixing is performed in mixing circuits 504 and 505 to extract intermediate frequencies, these intermediate frequency signals pass through band pass filters 506 and 507, and are further amplified by intermediate frequency amplifiers 508 and 509. After that, the two intermediate frequency signals are input to the comparator 510, respectively.

Since the light emitted from the laser emitter 403 is coherent light, the signals output from the intermediate frequency amplifiers 508 and 509 are sine waves. Then, the comparator 510
Then, the phase difference between the sine waves output from the two intermediate frequency amplifiers 508 and 509 is detected, the difference is input to the next phase difference calculating circuit 511, and the number of pulses commensurate with the phase difference is calculated. The circuit 511 outputs. In addition, the comparator 5
When comparing the phase differences of the signals at 10, it is necessary that the crest values of the two signals be the same. Therefore, in the present invention,
An AGC circuit 512 is provided. AGC circuit 512
Then, the signal from the intermediate frequency amplifier 508 is input, the peak value of the signal is determined as a reference value, the peak value of the signal input from the intermediate frequency amplifier 509 is compared, and the peak value output from the intermediate frequency amplifier 509 is set as the reference value. AGC less than the value
The signal increases the gain of the high frequency variable amplification circuit 502, and when the gain is opposite, the gain of the high frequency variable amplification circuit 502 is reduced by the AGC signal so that the peak values output from the intermediate frequency amplifiers 508 and 509 are always equal. Negative feedback control. The AGC signal is converted into a digital value by an A / D (analog / digital) converter 513 and input to the signal processing device 514. Due to the non-linear characteristic of the circuit that amplifies the semiconductor light receiving element 406 and performs frequency conversion, the phase characteristic also changes due to the change of the AGC voltage. Therefore, the detected phase difference is corrected by the CPU by this signal. This signal is also input to the CPU and is also used as a signal for confirming the operation during the diagnostic operation.

The signal processing unit 514 is a central processing unit (C
PU), ROM, RAM, PIO, SIO, CTC, and other hardware as a Mycoro computer. Various work programs are stored in the ROM, and depending on the environment of the collision prevention device at that time, appropriate input signal processing, output signal processing and the like are executed in accordance with the work program. In addition, 515 is
A rotary dip switch 515 that sets an interval "L" at which both cranes stop before a collision.

Next, an example of work performed by the signal processing device 514 will be described. 1. Distance "L" by rotary dip switch 515
2. Setting of the distance “L” visually from the remote controllers 8 and 9 (setting by remote operation) 3. Setting by the rotary dip switch 515 and setting by remote operation can be performed in two steps. (It is also possible to temporarily stop at the distance set by the rotary dip switch 515, release the stopping operation, and then slowly move to the set position by remote operation.) 4. Within the set distance (interval) "L" At this time, the relay 516 for controlling the electric motor 3 in the high voltage circuit 6 is turned on. 5. When the CPU determines that the distance can be measured because the AGC signal is within the predetermined range.
Outputs an enable signal to all circuits. 6. When the relay 516 is in the non-excited state, the CPU checks the operation of the internal circuit and diagnoses whether there is any failure (diagnose function). 7. If the distance between the cranes is within "L" and the light-shielding operation is performed for a predetermined time, for example, 1 second or more, it is determined that some failure has occurred. However, in the case of instantaneous light blocking, it is determined that an animal such as a bird has blocked the optical path, and the failure is not determined. 8. Give a warning when the set value of the distance "L" by the rotary dip switch or remote controller deviates from the distance measurable distance, and prohibit any operation. 9. If the distance cannot be measured due to external noise or the like even though the distance is within the measurable distance, the measurement result is discarded.

Next, the outline of the operation of the present invention will be described using a flow chart. In step S1 of FIG.
When the operation switch is turned on from the remote controller 8 or 9, all setting values of the signal processing device 514 and the like are initialized. In step S2, the designated mode of the mode switch of the remote controller 8 or 9 is read. In step S3, if the mode 1 or the distance set by the rotary dip switch 515 is read, the process proceeds to step S4. If the mode 2 or the distance set by the remote controller 8 or 9 is read, the step S3 is performed.
If the distance is set by the remote controller 8 or 9 in mode 3, the process proceeds to step S6.

When the process proceeds to step S6, the distance "L" is set by using the ten keys of the remote controller 8 or 9.
Is input and stored in the ROM of the signal processing device 514 (step S7). When the process proceeds to step S4, the distance "L" set by the rotary dip switch 515 is set.
Is read into the RAM of the signal processing device 514, and when the process proceeds to step S5, the distance “L” previously set from the remote controller 8 or 9 is set to the signal processing device 51.
Read in RAM of No.4.

When the work of step S5 or step S6 is completed, the process proceeds to step S8, and the laser light emitter 40
3 is turned on, and all circuits are inspected in step S9. When a failure is found in step S10, step S
A failure signal is output at 11 to end the operation. When no failure is found in the circuit, distance measurement is performed in step S12, the circuit is checked in step S13, and when no failure is found in the circuit in step S14, the distance between adjacent cranes is measured. If the distance is within the predetermined distance "L", the distance is output (step S15).

Next, the distance between adjacent cranes is
The operation when the distance is within the measurable range will be described with reference to the flowchart shown in FIG. In step S20, when the light receiving unit 402 emits light from the light transmitting unit 401 and receives the light reflected by the reflector 10, distance measurement is performed in step S21, and if the distance is closer than 2 meters and farther than 30 meters. , Step S22
Go to and determine that distance measurement is impossible. If the distance is within the range of 2 to 30 meters, step S2
If the distance can be measured in step 3, the process proceeds to step S24, and it is determined whether the measured distance is farther than, or equal to, the preset distance "L", and if it is farther than that distance, the process proceeds to step S25. And do nothing. When the distance is equal to or shorter than the distance L, the process proceeds to step S26, the ON output is generated, the signal is sent to the high voltage circuit 6, and the electric motor 3 is stopped.

In step S20, when the light from the light transmitting section 401 does not enter the light receiving section 402, the step S20 is performed.
Proceeding to 27, it is determined whether the light-shielding time exceeds or does not exceed 1 second. When it exceeds 1 second, it is determined in step S28 that the device is out of order.

In the above embodiment, when the mutual cranes reach the set distance, only the own crane is stopped. However, for example, the crane B in FIG. When the crane A approaches, there is no way to stop it. The equipment according to the present invention may be installed before and after the crane, but the equipment cost increases. Therefore, in another embodiment of the present invention, a light receiving device and a light emitting device for emergency stop are provided in the interface device 7 and the like,
When the signal processing device 514 determines that another crane has approached beyond the set distance on the side of the crane that is stopped, an emergency stop signal is issued from the light emitting device and the light receiving device of the approaching crane receives a warning. It can also be configured to stop the approaching crane.

As described in detail above, according to the present invention, since there is only one optical system for distance measurement, the operation of optical axis alignment is extremely simple as compared with the conventional device. And the cost will be lower. Also, since the modulation frequencies of the emitted light and the reflected light are converted to lower ones and the phases of the two are compared, a malfunction due to disturbance is eliminated. Also, as an accessory effect, no malfunction occurs even if the animal is shielded from light for a short time.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a crane to which a collision prevention device according to the present invention is applied.

FIG. 2 is a block diagram showing details of a light transmitting / receiving unit 4 and a controller 5.

FIG. 3 is a flowchart for explaining the operation of the embodiment of the present invention.

FIG. 4 is a flowchart for explaining the operation of another embodiment of the present invention.

[Explanation of symbols]

 1 ... Rail 2 ... Wheels 3 ... Electric motor 4 ... Transmitting / receiving unit 5 ... Controller 6 ... High-power circuit 7 ... Interface device 8 ... Remote controller 10 ... Reflector 401, light transmitting unit 402, light receiving unit 510, comparator 511, phase difference calculation circuit 511 514, signal processing device 515, rotary dip switch

Claims (6)

[Claims] 1. A collision in which light emitted from one of the moving bodies is reflected by the other moving body to measure an interval between the moving bodies, and an approach signal is generated when the measured distance is within a predetermined value. In the prevention device, distance setting means for setting the approach distance of both moving bodies, distance storing means for storing the distance set by the distance setting means, phase of light emitted from one of the moving bodies and phase of reflected light And a distance calculated from the phase difference calculated by the calculating means and a set distance stored in the distance storage means, and the distance calculated from the calculation result of the calculating means is the set distance. And a signal generating means for outputting a signal when the time is within the range. 2. The phase of a signal obtained by reducing the modulation frequency of the light emitted from one of the moving bodies and the frequency of the received reflected light to a predetermined value is compared by a calculating means.
The described collision prevention device. 3. The collision prevention device according to claim 1, further comprising means for determining that an accident has occurred when light emitted from one of the moving bodies is blocked for a predetermined time or longer. 4. The collision prevention device according to claim 1, wherein the light transmitting section provided on one of the moving bodies has a laser emitting body. 5. The collision prevention device according to claim 1, wherein the distance setting means for setting the approach distance between the two moving bodies includes a numerical value setting means arranged in the device. 6. The collision prevention device according to claim 1, wherein the distance setting means for setting the approach distance between the two moving bodies includes a numerical value setting means arranged in a remote controller outside the apparatus.