A motion sensor includes a sensor element to sense a motion, and a controller communicably coupled to the sensor element. The controller is configured to set a detection sensitivity of the motion sensor to a maximum setting of the detection sensitivity. The controller is further configured to decrease the detection sensitivity of the motion sensor upon a detection of the motion until the motion is undetectable by the motion sensor at a decreased setting of the detection sensitivity. The controller is further configured to increase the detection sensitivity of the motion sensor until the motion sensor detects the motion at an increased setting of the detection sensitivity and to set the detection sensitivity of the motion sensor to a new setting based on the increased setting.

A method of calibrating a pan, tilt, zoom (PTZ) camera with a fixed camera utilizing an overview image of a scene captured by the fixed camera, and an image of the scene captured by the PTZ camera when directed in a first direction. By matching features in the overview image and the PTZ camera image, a first calibration is carried out by correlating the first direction to matching features in the overview image. A mapping between the PTZ camera image and the overview image is defined based on the matching features. The mapping is used to map an object from the PTZ camera image to the overview image. Based on an appearance of the mapped object, a quality of the mapping is calculated. If the quality is not good enough, the PTZ camera is redirected to a second direction, and a further calibration is carried out by again.

The present invention relates to a gas sensing device comprising: a gas sensing part for outputting a gas detection result; and a correction control part for changing the value outputted from the gas sensing part to a reference value when the output value is lower than the reference value.

The present invention relates to a gas sensing device comprising: a gas sensing part for outputting a gas detection result; and a correction control part for changing the value outputted from the gas sensing part to a reference value when the output value is lower than the reference value.

Use of multiple sensors to determine whether motion of an object is occurring in an area is described. In one aspect, an infrared (IR) sensor can be supplemented with a radar sensor to determine whether the determined motion of an object is not a false positive.

An apparatus and method for detection of methane in an environment, including a housing with a sensor printed circuit board and a processor printed circuit board interconnected to and thermally insulated from the sensor printed circuit board. The sensor printed circuit board includes a first tuning fork isolated from the environment, and a second tuning fork exposed to the environment. The tuning forks are attached to opposite sides of the sensor printed circuit board. The processor printed circuit board includes processing circuitry interconnected to the first tuning fork and the second tuning fork, which receives vibration frequency signals therefrom, and is programmed to determine a frequency difference between the frequency of vibration of the first tuning fork and the frequency vibration of the second tuning fork, and if the frequency difference is greater than a predetermined threshold, then setting an alarm to indicate the presence of methane.

A gas alarm for detecting a target gas based on a resistance value of a sensor element comprises a measuring unit to measure a characteristic value of the sensor element, a heating control unit to control a heater to perform a heating process to heat the sensor element, a determining unit to determine, based on the characteristic value, whether the sensor element is in a blunt state in which sensitivity of the sensor element is decreased, and an aborting control unit to abort the heating process to determine whether the sensor element is in the blunt state when a characteristic value of the sensor element measured by the measuring unit after beginning of the heating process by the heating control unit meets a predetermined condition.

A method of rotating a surveillance camera having an acceleration sensor and being controllable by a processor to maintain a tilt-angle to conform to a command tilt-angle, includes the steps of moving the surveillance camera tilt to a predetermined command tilt-angle in response to a signal from the processor; periodically calculating estimated tilt-angles by using acceleration values in at least one axis of an acceleration sensor; calculating a difference value between an estimated tilt-angle of a current period and an estimated tilt-angle of a previous period; and when the difference value between the estimated tilt-angles exceeds a set limit, moving the camera to another position to correct the tilt angle according to the difference calculate.

A gunshot detection system includes gunshot sensor units and a control panel. The gunshot sensor units generate audio data and encrypt the audio data using an encryption key before storing the audio data and/or sending it to the control panel. The control panel decrypts received encrypted audio data using a decryption key. The encryption keys might be programmed at the control panel and distributed to the gunshot sensor units. The control panel would also store decryption keys for decrypting the audio data from each of the different gunshot sensor units. An additional layer of end-to-end encryption is provided for messages exchanged between the devices. The gunshot sensor units can also be equipped with wireless interfaces for communicating with the control panel over a communication network. To address potential bandwidth issues, the gunshot sensor units determine current network conditions and compress the audio data based on the current network conditions.

A gunshot detection system includes gunshot sensor units and a control panel. The gunshot sensor units generate audio data and encrypt the audio data using an encryption key before storing the audio data and/or sending it to the control panel. The control panel decrypts received encrypted audio data using a decryption key. The encryption keys might be programmed at the control panel and distributed to the gunshot sensor units. The control panel would also store decryption keys for decrypting the audio data from each of the different gunshot sensor units. An additional layer of end-to-end encryption is provided for messages exchanged between the devices. The gunshot sensor units can also be equipped with wireless interfaces for communicating with the control panel over a communication network. To address potential bandwidth issues, the gunshot sensor units determine current network conditions and compress the audio data based on the current network conditions.