39results about How to "Avoid missing alarms" patented technology

The invention discloses a warning method and device for a minimum safe altitude of an aerial target. The warning method comprises the following steps of: judging whether a first altitude difference is larger than a set warning interval height, wherein the first altitude difference is the altitude difference between the height of the current position of the aerial target and the height of a surficial grid where horizontal coordinates of the current position of the aerial target are located; judging wherein a connection line between the current position and an extrapolated warning track point is intersected with a grid cube if the first altitude difference is larger than the warning interval height; and determining whether to give an alarm according to the distance between the current position and an intersection if the intersection exists. As the step of judging whether the aerial target can penetrate through the surficial grid and is intersected with the grid cube within a set time slot is also added in the invention, the phenomenon of incapability of giving the alarm when the aerial target violates the safe altitude during the flight, so that missed alarms can be avoided.

The invention belongs to the technical field of safety prewarning, and particularly relates to a system and method for prewarning of child falling-off-bed. The system comprises a covering layer and strain foil prewarning devices, wherein the periphery of the covering layer is provided with prewarning areas, the strain foil prewarning devices are distributed in the prewarning areas of the covering layer, and when the child reaches one prewarning area, the strain foil prewarning device in the corresponding prewarning area is squeezed and triggered to send out a warning signal. According to the system and the method, the prewarning areas with certain widths are arranged in bedding articles such as a bed mattress, the prewarning areas are provided with a large number of the strain foil prewarning devices, when the child approaches the prewarning areas, the strain foil prewarning devices are triggered to send out the warning signal, and prewarning accuracy can be improved to the maximum extent. Due to the fact that the prewarning areas are a certain distance away from the edge of the bed, enough time is reserved for a caregiver to take protection measures. Due to the fact that the strain foil prewarning devices are arranged in the bedding articles, extra space is needless to be occupied.

The invention relates to a laser detection and control system for barriers between a shield door of a metro platform and a train door, comprising a monitoring unit, a control unit and an alarm unit, wherein, the controller comprises a CPU module, a liquid crystal terminal, a signal isolator, buttons and a safety relay; generating lasers are respectively installed on a front bracket, and a laser receiver or a laser reflection plate is installed on a rear bracket corresponding to the front bracket; the control ends of the generating lasers are connected with the output end of the controller, and the output end of the laser receiver is connected with the input end of the controller; the corresponding output end of the controller is correspondingly connected with the control input end of the shield door; and the corresponding output end of the controller is connected with a buzzer and a caution light of the platform. The laser detection and control system realizes the intelligent operation of judging the existence of barriers between the shield door of the metro platform and the train door, has the advantages of compact integral structure, reasonable cost, easy and convenient installation, simple and intelligent operation, stable and reliable performance, higher practicability and favorable development prospect, and is applicable to metro platform.

The invention provides an energy-saving alarm method and alarm system based on a Bluetooth beacon. The method comprises the steps that whether a sampling result exceeds at least one preset early warning threshold value and at least one preset alarm threshold value or not is judged, and if yes, a Bluetooth sensor adjusts the sampling period and the broadcasting period of the Bluetooth sensor according to the preset early warning threshold value or the alarm threshold value; whether the average receiving period of the Bluetooth broadcast signals received by the Bluetooth beacon and adjusted by the Bluetooth sensor is not higher than or lower than at least two average receiving periods of the Bluetooth beacon is judged; and if the Bluetooth sensor still cannot ensure that the average receiving period of the Bluetooth broadcast signal of the Bluetooth sensor received by the Bluetooth beacon is not higher than or lower than at least two average receiving periods of the Bluetooth beacon through adaptive adjustment, the Bluetooth sensor initiates connection with the Bluetooth beacon to give an abnormal alarm. According to the technical scheme, the Bluetooth sensor and the Bluetooth beaconrealize broadcast in two directions, electric energy is saved, it is ensured that alarms can be sent out in time, and missed alarms are avoided.

The invention discloses a warning method and device for a minimum safe altitude of an aerial target. The warning method comprises the following steps of: judging whether a first altitude difference is larger than a set warning interval height, wherein the first altitude difference is the altitude difference between the height of the current position of the aerial target and the height of a surficial grid where horizontal coordinates of the current position of the aerial target are located; judging wherein a connection line between the current position and an extrapolated warning track point is intersected with a grid cube if the first altitude difference is larger than the warning interval height; and determining whether to give an alarm according to the distance between the current position and an intersection if the intersection exists. As the step of judging whether the aerial target can penetrate through the surficial grid and is intersected with the grid cube within a set time slot is also added in the invention, the phenomenon of incapability of giving the alarm when the aerial target violates the safe altitude during the flight, so that missed alarms can be avoided.

The invention provides a method for automatically updating the radar clutter map for micro-target detection on the pavement, which can update the clutter map in real time, improve the detection probability of micro-targets whose echo power is on the edge of the detection threshold, and avoid missed and false alarms. After the road surface micro target detection radar is turned on, it performs a pre-scan to generate two clutter images and stores them, one of which is smoothed and used for CFAR detection during the detection scan, and the other image is directly stored without any processing . In each detection scan, the smoothed clutter map is called. After the scan is completed, the unsmoothed clutter map is updated according to the automatic update judgment conditions of the clutter map, and the updated clutter map is smoothed and replaced by the previous one. The smoothed clutter map is used for the next detection scan, and so on. Because of the existence of automatic update judgment conditions, it is avoided to update the target into the clutter map, resulting in missed alarms; in rainy and snowy weather, the clutter map can also be updated in real time to avoid false alarms caused by accumulated water or snow.

Aiming at the multi-channel synthetic aperture radar system under the strong clutter background, the present invention combines the Robust Principal Component Analysis (RPCA) method and the amplitude-phase joint detection method to propose a multi-channel synthetic aperture radar RPCA amplitude-phase joint target detection method and device . In this method, the focused image columns of each channel are vectorized and stacked to obtain a matrix X, and then the matrix X is decomposed by the improved RPCA method to obtain a low-rank matrix L and a sparse matrix S, and finally the phase information is introduced for joint detection of amplitude and phase. The invention comprehensively considers the specific clutter and moving target information, effectively improves the moving target detection performance; fully combines the advantages of RPCA and amplitude-phase joint detection method through the two-step detection method, and reduces the false alarm rate under the condition of low signal-to-clutter ratio ; and the matrix decomposition technology adopted by the method of the present invention can greatly reduce the computational complexity and improve the algorithm efficiency.