Technical Field

The invention relates to a method for adjusting a sensitivity of a shock sensor which is used for sensing an attack on a facility equipped with the shock sensor, which method can be carried out very quickly, simply and accurately, and to a corresponding shock sensor.

Background Art

With the development of the society and technical advancement, more and more convenient facilities, such as automobiles, motorcycles, automatic teller machines (ATM) and the like, appear in our daily life. These facilities normally need to be equipped with alarm devices against an attack, and when the facilities are subjected to the attack, the alarm devices can sense the attack and generate corresponding alarms, such as sound alarms.

At present, the alarm device normally is a shock sensor. That is, it is determined whether the facilities are subjected to the attack according to a shock signal detected by the shock sensor. The existing shock sensor mainly executes a detection method as follows. A threshold value is predetermined, an amplitude of the shock signal detected by the shock sensor is compared with the threshold value, and exceeding of the threshold value indicates that the facility is subjected to the attack, thus generating a corresponding alarm. In some cases, in addition that the amplitude of the shock signal detected by the shock sensor is compared with the threshold value, one or more judgment conditions need to be met, in order to further decrease false alarm and missing alarm.

Therefore, the existing detection method involves with comparison of the amplitude of the shock signal with a threshold value, and when the threshold value is set to be too low, a noise may be mistaken easily as the attack so as to lead to false alarm. Rather, when the threshold value is set to be too high, some alarms may be missed and great loss will be caused for the corresponding facility.

It may be understood by a person skilled in the art that the threshold value corresponds to a sensitivity of the shock sensor and the sensitivity needs to be adjusted when the shock sensor is used in different applications and sites. In general, the shock sensor is provided with a sensitivity adjusting device. When the shock sensor has been installed on the facility, the installation personnel adjusts the sensitivity by means of the sensitivity adjusting device in such a manner that an estimated threshold value is firstly set by means of the sensitivity adjusting device according to his/her experience and then is checked by means of a simulated attack. Therefore, it is a trial-and-error method and even can not achieve a suitable sensitivity for a particular application. Furthermore, it is very difficult and complicated to adjust the sensitivity well.

Thus, it is desirable to provide a method for adjusting a sensitivity of a shock sensor which can be carried out very quickly, simply and accurately, and to provide a corresponding sensor.

Summary of the Invention

In view of the problems existed in the prior art, an object of the invention is to provide a more simple method for adjusting accurately a sensitivity of a shock sensor and a corresponding shock sensor.

For achieving this object, in one aspect, the present invention provides a method for adjusting a sensitivity of a shock sensor which is used for sensing an attack on a facility equipped with the shock sensor, wherein the shock sensor is provided with a mode setting device and said method comprises the following steps:

a) setting the shock sensor to an installation mode by means of the mode setting device and powering the shock sensor on;

b) simulating a desired attack in a predetermined time period and recording a amplitude of the attack in the predetermined time period by means of the shock sensor; and

c) determining the sensitivity of the shock sensor at least based on the amplitude of the attack.

In accordance with a preferred embodiment of the invention, the shock sensor is provided with an indication unit; and when the shock sensor is set to the installation mode and is powered on, the indication unit generates a first indication; and/or when the predetermined time period ends, the indication unit generates a second indication.

In accordance with a preferred embodiment of the invention, the predetermined time period starts from a time at which the shock sensor is set to the installation mode and is powered on; and/or the predetermined time period is set to be about 3 minutes.

In accordance with a preferred embodiment of the invention, an environmental noise is estimated or measured and is taken into account when the sensitivity of the shock sensor is determined or when the desired attack is simulated; and/or the sensitivity of the shock sensor is determined at least based on the maximum of the amplitude of the attack, and preferably is determined to be equal to or greater than the maximum of the amplitude of the attack by about 30%, about 20% or about 10%.

In accordance with a preferred embodiment of the invention, the determined sensitivity of the shock sensor is assigned to a variable of a program stored in a microprocessor of the shock sensor or to a register of the microprocessor such that the shock sensor can be operated with the determined sensitivity; or the shock sensor is provided with a sensitivity adjusting device, and when the sensitivity of the shock sensor is determined, the shock sensor is switched from the installation mode to a normal mode by means of the mode setting device and then the determined sensitivity of the shock sensor is set by means of the sensitivity adjusting device.

In accordance with a preferred embodiment of the invention, the sensitivity adjusting device comprises a first DIP (dual inline-pin package) switch capable of being adjusted to select a sensitivity range for the shock sensor and a potentiometer capable of being adjusted to set the sensitivity of the shock sensor; when the first DIP switch needs to be adjusted for the determined sensitivity of the shock sensor, the indication unit generates a third indication; when only the potentiometer needs to be adjusted, the indication unit gives a fourth indication different from the third indication; and when the first DIP switch and the potentiometer is adjusted well, the indication unit is switched off or gives a fifth indication different from the third and fourth indications.

In accordance with a preferred embodiment of the invention, when the determined sensitivity of the shock sensor has been set well, the shock sensor is powered off; and when the shock sensor is powered on again, it will be placed into a normal working mode such the shock sensor can be operated with the determined sensitivity.

In accordance with a preferred embodiment of the invention, the indication unit comprises or is configured as an LED; and/or the mode setting device is configured as a second DIP switch; and/or the predetermined time period is adjustable.

For achieving this object, in another aspect, the present invention provides a shock sensor for sensing an attack on a facility equipped with the shock sensor, wherein the shock sensor comprises:

a sensing unit adapted to sense a shock signal generated by the attack;

a mode setting device adapted to set the shock sensor to an installation mode in which a sensitivity of the shock sensor is allowed to be determined at least based on an amplitude of a simulated attack; and

a microprocessor adapted to analyze and process the shock signal at least based on the determined sensitivity of the shock sensor.

In accordance with a preferred embodiment of the invention, the shock sensor further comprises a sensitivity adjusting device, and when the sensitivity of the shock sensor is determined, the shock sensor is set from the installation mode to a normal mode by means of the mode setting device and then the determined sensitivity of the shock sensor is set by means of the sensitivity adjusting device.

In accordance with a preferred embodiment of the invention, the sensitivity adjusting device comprises a first DIP switch capable of being adjusted to select a sensitivity range for the shock sensor and a potentiometer capable of being adjusted to set the sensitivity of the shock sensor; and/or the mode setting device is configured as a second DIP switch.

Brief Description of the Drawings

The invention and advantages thereof will be further understood by reading the following detailed description of some preferred exemplary embodiments with reference to the drawings in which:

Fig. 1 is a block diagram showing essential components of a preferred exemplary embodiment of a shock sensor for sensing an attack on a facility equipped with the shock sensor.

Fig. 2 is a flowchart showing a preferred exemplary embodiment of a method for adjusting a sensitivity of the shock sensor.

Detailed Description of Preferred Embodiments

Now, a shock sensor according to a preferred exemplary embodiment of the invention will be described with reference to Fig. 1. As previously described, the shock sensor is usually installed on some important facilities in order to sense a possible attack on the facilities and generate an alarm when the attack is determined as a real attack possibly breaking the facilities and/or causing any property loss.

As shown in Fig. 1, the shock sensor 1 mainly comprises a sensing unit 2, such as an acceleration sensor, for sampling a shock signal which is transmitted to the sensing unit 2, a sensitivity adjusting device 3 for adjusting the sensitivity of the shock sensor 1, an indication unit 4 at least for assisting in adjusting the sensitivity, an alarm unit 5 for generating the alarm in an optical and/or acoustic manner when the real attack is detected, and a microprocessor 6 for analyzing and processing the shock signal at least based on the adjusted sensitivity by using a predeterminated program.

For example, the sensing unit 2 samples the shock signal at a sampling frequency of about 2 kHz, preferably 2 kHz.

It should be understood by a person skilled in the art that the indication unit 4 and the alarm unit 5 are controlled by the microprocessor 6.

Preferably, as shown in Fig. 1, the microprocessor 6 is electrically connected with an output terminal 8 of the sensing unit 2 by means of a serial peripheral interface (SPI) 7.

Preferably, when the shock sensor 1 is installed on the facility and set to a normal working mode, the shock sensor 1 can be communicated with a control system (not shown) of the facility.

Generally, the sensitivity of the shock sensor 1 corresponds to a certain threshold value. As an example, by comparing an amplitude of the sampled shock signal generated by the attack with the threshold value (and additionally comparing a duration of the attack with a predeterminated duration), the microprocessor 6 analyzes the shock signal and generates an alarm when the attack is determined as the real attack.

According to a preferred embodiment of the invention, the indication unit 4 may be or comprise an LED.

As an example, the sensitivity adjusting device 3 comprises a first DIP switch and a potentiometer (POT). The first DIP switch is configured to set or select different sensitivity levels (ranges) for the shock sensor 1 as desired, and the potentiometer is used for setting accurately the sensitivity of the shock sensor 1. That is to say, the first DIP switch and the potentiometer cooperate with each other to set the sensitivity of the shock sensor 1. Once the first DIP switch and the potentiometer is adjusted well, the microprocessor 6 can determine the sensitivity of the shock sensor 1 according to adjusted positions of the first DIP switch and the potentiometer when the shock sensor 1 is powered on. In this case, the sensitivity of the shock sensor 1 can be maintained until the first DIP switch and/or the potentiometer is readjusted.

Preferably, the shock sensor 1 has four different sensitivity levels.

It should be understood by a person skilled in the art that the sensitivity adjusting device 3 is not limited to the above details and any types of devices capable of adjusting the sensitivity of the shock sensor 1 can be used.

As previously described, when the shock sensor 1 is installed on the facility, the sensitivity of the shock sensor 1 often needs to be adjusted according to different situations (such as environmental noise around the shock sensor 1) and application requirements. In the following, a preferred exemplary embodiment of a method for adjusting the sensitivity of the shock sensor 1 will be described in detail with reference to Fig. 2.

Fig. 2 is a flowchart showing the method for adjusting the sensitivity of the shock sensor 1. The method comprises four steps as follows.

In a first step SI, after the shock sensor 1 has been installed at a correct position on the facility, the shock sensor 1 is set to an installation mode by means of a mode setting device and then the shock sensor 1 is powered on. At this time, the shock sensor 1 is ready for the next step for simulating the attack.

It should be understood by a person skilled in the art that the shock sensor 1 may also be set to the installation mode before the shock sensor 1 is installed at the correct position on the facility.

According to a preferred exemplary embodiment, the mode setting device is a second DIP switch.

In a second step S2, a simulation operation of an attack having a desired amplitude is carried out to determine the sensitivity of the shock sensor 1. Preferably, the noise is estimated by the installation personnel or measured by means of any suitable devices, and the desired amplitude of the attack is determined in view of the noise. In a predetermined time period of the simulation operation, the attack is simulated by means of any suitable tools and the shock sensor 1 records the amplitude of the simulated attack in the predetermined time period. After the predetermined time period ends, the sensitivity of the shock sensor 1 is determined based on the amplitude of the simulated attack.

For example, the sensitivity of the shock sensor 1 is set to be equal to or greater than the maximum of the recorded amplitude by a predetermined value, such as about 30%, about 20%, about 10%, etc.

It should be understood by a person in the art that the noise may also be considered only when the sensitivity of the shock sensor 1 is determined.

For example, the predetermined time period may be about 3 minutes, preferably 3 minutes. Preferably, the predetermined time period automatically starts from a time at which the shock sensor 1 is powered on in the first step S I . The predetermined time period can be preprogrammed in the program stored in the microprocessor 6. According to a preferred exemplary embodiment, the predetermined time period is timed by means of an internal timer (not shown) of the microprocessor 6. More preferably, the predetermined time period can be adjusted as desired by means of a third DIP switch or any other suitable devices. It should be understood by a person skilled in the art that the predetermined time period may also start from any time after the first step 1 is carried out.

Preferably, when the predetermined time period ends, the microprocessor 6 can control the indication unit 4 such that an indication is generated to indicate the end of the simulation operation.

At this time, the determined sensitivity of the shock sensor 1 can be assigned to a variable of the program or a register of the microprocessor 6 such that the shock sensor 1 can be operated with said determined sensitivity. However, if the shock sensor 1 is powered off, the determined sensitivity may be lost. Furthermore, some users still wish to manually adjust the sensitivity of the shock sensor 1 for example by means of the first DIP switch and the potentiometer, although the determined sensitivity can be restored by means of some technical device known to a person skilled in the art. To this end, the next step should be carried out.

In a third step S3, the determined sensitivity of the shock sensor 1 is set by means of the sensitivity adjusting device 3 (for example by means of the first DIP switch and the potentiometer). Firstly, the shock sensor 1 is switched from the installation mode to a normal mode preferably by means of the second DIP switch, and then the determined sensitivity of the shock sensor 1 is set preferably with the help of the indication unit 4 (for example the LED). For example, when the microprocessor 6 determines that the first DIP switch needs to be adjusted for the determined sensitivity, the LED flashes. When the first DIP switch is adjusted well, the LED does not flash any longer. At this time, if the LED is lighted on, it is indicated that the potentiometer needs to be adjusted. If the LED is switched off, it is indicated that the determined sensitivity has been adjusted well.

Preferably, when the determined sensitivity is adjusted well, the shock sensor 1 is powered off, in order to make the shock sensor 1 work more reliably. In this case, the next step should be carried out.

In a fourth step S4, the shock sensor 1 is powered on again and the shock sensor 1 will be automatically placed into a normal working mode. In this case, when the amplitude of any attack is greater than the set sensitivity (and if any, one or more judgment conditions must also be met), the shock sensor 1 will generate an alarm. The basic concept of the invention is to determine a sensitivity of the shock sensor based on a simulated attack having a desired amplitude in the installation mode. It should be understood that the attack may be of any type as desired. Any methods and shock sensors that employ the above basic concept fall within the scope of the invention.

While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the invention. The attached claims and their equivalents are intended to cover all the modifications, substitutions and changes as would fall within the scope and spirit of the invention.