JP3027853B2 - Anti-collision sensor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a collision prevention sensor attached to a plurality of carts traveling on a predetermined track.

[Conventional technology]

2. Description of the Related Art Conventionally, carts running on a predetermined track such as a golf cart are self-propelled, and therefore, when approaching a cart ahead, it is necessary to apply a brake to prevent a collision. Therefore, in each cart, a transmitter that periodically outputs a high frequency signal of a fixed frequency, for example, 100 KHz, a receiver that is provided in front of the cart and receives a signal from the cart in front, and that a signal is received. Is provided with a control circuit for detecting the braking force and applying a brake to the cart. FIGS. 5 (a) to 5 (c) are time charts showing the operation of such a conventional golf cart collision prevention sensor, in which a signal of a constant frequency is sent out at an arbitrary cycle to prevent the sneaking around. During this time, when a signal is received from the cart ahead, the cart is braked.

[Problems to be solved by the invention]

However, in such a conventional collision prevention sensor, the presence or absence of the cart in front can be detected,
There is a disadvantage that the position of each cart on the track cannot be recognized from the outside.

The present invention has been made in view of such a problem of the conventional collision prevention sensor, and has been made in view of the problem that a code signal can be sent to the outside in order to recognize the positions of a plurality of carts from outside a track. Subject.

[Means for solving the problem]

The present invention relates to an anti-collision sensor attached to each of a plurality of carts traveling on a predetermined track, wherein the anti-collision sensor is provided in front of the cart and receives a signal of a first frequency, and the A transmitter for transmitting backwards,
An output circuit for outputting an output when a signal is obtained from the receiving sensor; first oscillating means for intermittently oscillating a signal of a first frequency to give to a transmitter; and a receiving sensor for oscillating by the first oscillating means. A prohibition circuit for prohibiting the application of the obtained signal to the output circuit, and a second coded identification signal unique to each cart while the signal of the first oscillating means is stopped.
A code signal oscillating means for generating a code signal having a frequency of ## EQU1 ## and a selecting means for switching the outputs of the first oscillating means and the code signal oscillating means to provide the output to the transmitter.

[Action]

According to the present invention having such characteristics, the second frequency different from the first frequency during the oscillation of the signal by the first oscillation means.
The transmitter transmits a signal in which an identification signal unique to each cart is coded according to the frequency. Therefore, the position of each cart can be recognized by the identification signal receiving device provided on the side of the track. During the transmission of the identification signal of the second frequency, the prohibition circuit is not operated.

〔Example〕

FIG. 1 is a block diagram showing an overall configuration of a collision prevention sensor according to one embodiment of the present invention, and FIG. 2 is a schematic diagram showing a cart to which the collision prevention sensor is mounted. The cart 1 is provided with a receiving sensor 2 at the front and a transmitter 3 at the back. The receiving sensor 2 and the transmitter 3 are connected to a control circuit 4. As shown in FIG. 1, an amplification circuit 11 for amplifying the output of the reception sensor 2 is provided in the control circuit 4. The amplification circuit 11 includes a band-pass filter for amplifying the signal of the frequency f1 which is the reception signal, and the output thereof is
Given to. The prohibition circuit 12 supplies an input signal to the output circuit 14 via the delay circuit 13 while the prohibition signal is not supplied. The output circuit 14 outputs a relay signal or the like for applying a brake when a received signal exceeding a certain level is obtained. In the control circuit 4, a first oscillation circuit 15 used for collision prevention is provided. The oscillating circuit 15 is a first oscillating means which is used for collision prevention and intermittently oscillates a signal for a predetermined period of time, for example, 5 ms at a randomly changing random period of 60 to 120 ms as described later. . The oscillation frequency of the oscillation circuit 15 is constant, and this frequency is defined as a first frequency (f1).
The oscillation output is supplied to a selector 16 as selection means, and its envelope signal is supplied to a prohibition circuit 12, a selector 16 and a timing circuit 17. The timing circuit 17 supplies a timing signal to the second oscillation circuit 18 after the oscillation from the oscillation circuit 15 until the next oscillation occurs. The second oscillating circuit 18 oscillates at a second frequency (f2) different from the first frequency in accordance with a signal obtained by encoding an identification signal unique to each cart. Can be
Here, the timing circuit 17 and the oscillating circuit 18 constitute a code signal oscillating means 19 for generating a code signal of the second frequency while the signal of the first oscillating means is stopped. The selector 16 selectively switches the outputs (f1, f2) of the first and second oscillation circuits, and the output is supplied to the transmitter 3 via the drive circuit 20.

FIG. 3 shows a trajectory for transporting the cart. For example, in a golf course or the like, golf carts 1a, 1b,... Each of the halls 1H, 2H ... has a second frequency f2
A fixed station 21 for receiving the signal is provided. Each fixed station comprises a receiving circuit for receiving a signal of frequency f2, and a decoder for detecting the signal and identifying a code number of each cart.

Next, the operation of this embodiment will be described. FIG. 4 (a) by the first oscillation circuit 15 from the control circuit 4 of each cart.
As shown in the figure, a signal of a frequency (f1) is output at a random period and a constant length, for example, with a width of 5 ms. At this time the fourth
Since the prohibition signal is supplied to the prohibition circuit 12 as shown in FIG. 2B, the output of the amplifier circuit 11 is not supplied to the delay circuit 13, so that the signal can be prevented from sneaking. However, no signal from the cart ahead is received. At timings other than the reception prohibition timing, reception becomes possible as shown in FIG. 4 (b). Therefore, when a signal from the front cart is received as shown in FIG.
To the delay circuit 13 via Delay circuit 13
In this case, short-time noise is prevented, and when a signal of frequency f1 is received from the front cart as shown in the reception signal of FIG. Will work.

On the other hand, during the transmission timing of the frequency f1, FIG.
As shown in (2), the identification signal encoded at the frequency f2 is output to the outside. Therefore, the cart is a fixed station for receiving identification signals.
When passing through the position of 21, the identification signal can be received by the fixed station 21 arranged on the transport path of the cart. In this case, since the frequencies are different, it is not necessary to operate the prohibition circuit while transmitting the identification signal. Therefore, if a signal from the front cart is received even while the identification signal is being received, the cart can be braked and the possibility of collision can be eliminated.

〔The invention's effect〕

As described in detail above, according to the present invention, the transmission of the identification signal is made different from the frequency of the signal for preventing collision, and when the identification signal is output, the prohibition circuit is not operated so that a collision is possible. The advantage is that the individual number of each cart can be recognized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a collision prevention sensor according to one embodiment of the present invention, FIG. 2 is a diagram showing an outline of a cart running on a track and a fixed station arranged beside the cart, and FIG. FIG. 4 is a diagram showing an example of a cart trajectory. FIG. 4 is a time chart showing the operation of the cart collision prevention sensor of the present embodiment.
FIG. 1 is a time chart showing the operation of a conventional collision prevention sensor. 1 ... cart, 2 ... reception sensor, 3 ... transmitter, 4 ...
... Control circuit, 12 ... Prohibition circuit, 14 ... Output circuit, 15 ...
Oscillation circuit, 16 ... Selector, 17 ... Timing circuit, 18
…… Oscillation circuit, 19 …… Code signal oscillating means

Claims (1)

(57) [Claims] An anti-collision sensor attached to each of a plurality of carts traveling on a predetermined track, wherein the anti-collision sensor is provided in front of the cart and receives a signal of a first frequency, and provided in the back of the cart. A transmitter for transmitting a signal backward, an output circuit for outputting when a signal is obtained from the reception sensor, a first oscillation for intermittently oscillating the signal of the first frequency and giving the signal to the transmitter Means, a prohibition circuit for prohibiting a signal obtained from the reception sensor at the time of oscillation by the first oscillating means from being applied to the output circuit, and each of the carts while the signal of the first oscillating means is stopped. Code signal oscillating means for generating a code signal of a second frequency obtained by encoding a unique identification signal to the transmitter; And a step.