JPS6030319Y2 - Baggage detection device - Google Patents

Description

[Detailed explanation of the idea] The present invention relates to a load detection device for an unmanned forklift.

When loading cargo into a warehouse with an unmanned forklift, it is necessary to accurately detect the position of the cargo (placed on a pallet).

Conventionally, there are detectors that use light, ultrasonic waves, or the like as detectors for such baggage.

However, the conventional detector described above has the disadvantage that it is difficult to accurately detect the position because it is easily influenced by the environment.

The present invention has been made for the purpose of eliminating the above-mentioned conventional drawbacks, and provides a cargo detection device that determines when an unmanned forklift has hit the lowest cargo and obtains a cargo detection signal.

Hereinafter, the present invention will be described in detail based on an embodiment of the present invention with reference to the accompanying drawings.

In FIG. 1, an unmanned forklift 1 performs cargo handling work by automatically traveling along a guide cable (not shown) laid in a travel path, lane, etc. This forklift 1 is equipped with a travel pulse generator 3. It is arranged.

This running pulse generator 3 has a certain running distance, for example, 1 m.
One pulse signal Ps is output every m.

Therefore, by measuring the number of pulses, the traveling distance of the forklift 1 can be detected.

The period of the pulse signal Ps is the forklift 1
It changes depending on the vehicle speed.

This traveling pulse signal Ps is transmitted to the baggage detection device 1 shown in FIG.
It is added to the running pulse counter 15 of 0 as a down pulse signal.

The time pulse generator 12 generates a pulse signal p at regular intervals.
t is output and added to the time counter 16 as a down pulse signal.

On the other hand, as shown in FIG. 1, the lift position of the fork 2 of the unmanned forklift 1 carrying the cargo is set to a height that is just above the ground, that is, the pallet 5a on which the cargo 6a is placed is not dragged and this pallet 5a is in the lane. The vehicle is made to travel forward at a constant speed along a predetermined travel path at a height that hits the pallet placed on the vehicle.

At this time, the running pulse counter 15 and the time counter 16 do not operate even if pulses Ps and Pt are applied from the running pulse generator 3 and the time pulse generator.

When the forklift 1 enters a predetermined lane 4, the sequence control circuit 11 (FIG. 2) outputs preset data Da and Db.

Data Da is added to multiplier 13. This multiplier 13
multiplies the data Da by an appropriate coefficient K according to the vehicle speed of the forklift 1.

That is, when the vehicle speed is fast, it is multiplied by a large value K, and when it is slow, it is multiplied by a small value K.

During normal driving, the driving pulse counter 15
This is to change the value of the data Da according to the vehicle speed of the forklift 1 so that the content of the data Da becomes 0 before the time counter 16 does.

The frequency-voltage converter 14 outputs a signal es according to the frequency of the pulse signal Ps, and adds it to the multiplier 13.

The multiplier 13 multiplies the data Da by a predetermined coefficient in accordance with the input signal es, outputs the data as data Da', and presets the data in the running pulse counter 15.

Further, the data Db is preset in the time counter 16 as is.

The running pulse counter 15 and the time counter 16 are counted down each time the running pulse Ps and the time pulse pt are added.

While the vehicle is running at a constant speed, the content of the running pulse counter 15 becomes 0 before the time counter 16, and the NAND circuit N1
A reset signal is outputted from , and applied to the running pulse counter 15 and time counter 16 via the OR circuit OR to reset these counters.

Then, data Da' and Db are preset again.

Such operations are repeatedly performed while the forklift 1 is traveling at a constant speed.

When the pallet 5a of the forklift 1 hits the pallet 5b on which the load 6b is placed in the lane 4, the vehicle speed of the forklift 1 decreases.

Then, the period of the output pulse Ps of the running pulse generator 3 becomes longer, and the countdown of the running pulse counter 15 becomes slower.

On the other hand, the time pulse generator 12 outputs a pulse signal pt at the constant time interval t.

Therefore, the content of the time counter 16 becomes 0 before the running pulse counter 15.

The NAND circuit N2 outputs a signal when the content of the time counter 16 becomes O.

This signal is then used as a baggage detection signal.

This cargo detection signal is added to the travel control device (not shown),
The forklift 1 is immediately stopped.

The vehicle speed of the forklift 1 in the lane, the period t1 of the time pulse pt, the preset data Da, Db, etc. are such that when the forklift 1 hits a load placed in the lane, the load is not moved and the load is not moved. Of course, the value is set to an appropriate value so that the forklift 1 can be stopped in a short time.

Then, the vehicle may be moved back a predetermined distance from this stop position to perform a search operation for determining the height of the cargo, etc., and cargo handling work.

As explained above, according to the present invention, the position of cargo can be accurately detected without being affected by the environment, and it can also be easily installed on conventional unmanned forklifts.

Further, there are advantages such as a simple configuration and the ability to provide an inexpensive device.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an unmanned forklift truck equipped with a load detection device according to the present invention, and FIG. 2 is a block diagram showing an embodiment of the load detection device according to the present invention. 1...Forklift, 2...Fork, 3...Travel pulse generator, 5a, 5b...
Song palette, 6a, 6b... Luggage, 11...
... Sequence control circuit, 12 ... Time pulse generator, 13 ... Multiplier, 14 ...
Frequency voltage converter, 15... Traveling pulse counter, 16... Time counter, N1°N2...
...Nand circuit.

Claims (1)

[Scope of utility model registration request] In an unmanned forklift that performs cargo handling work according to a predetermined sequence, there is provided a travel pulse generator that outputs a travel pulse every time it travels a certain distance, a time pulse generator that generates a time pulse at a certain time interval, and a time pulse generator that outputs a travel pulse every time it travels a certain distance. a travel pulse counter that uses the time pulse as a down input; a time pulse counter that uses the time pulse as a down input; a sequence control circuit that presets predetermined data in each of the counters when the forklift enters a predetermined lane; and a time pulse counter that uses the time pulse as a down input. It is equipped with a gate circuit that outputs a load detection signal when the content of the counter reaches 0 before the content of the traveling pulse counter, and when the opposite occurs, resets both counters and presets each data. The load detection signal is obtained when the loaded load hits the loaded load and the vehicle speed decreases and the time pulse counter reaches 0 first. This is a baggage detection device.