Detection and alarm device for retention of passengers in lift car

The invention discloses a car passenger retention detection and alarm device, which relates to the technical field of detection devices and comprises a main controller, a car human body detection module, an elevator control system communication interface, a five-party intercom system control interface and a voice storage and broadcast unit. An external sensor is not needed, the state of the elevator can be obtained only by communicating with the elevator control system, although universality is poor, installation is convenient and fast for an elevator control system manufacturer, and the cost for achieving signal collection is very low. Compared with a camera judgment mode, the passenger retention lift car detection is realized based on the infrared switch sensor and the logic judgment unit, the cost advantage is obvious, and the judgment result is accurate. The alarm device is integrated with the voice broadcast device, the alarm function device can be realized by adding several input and output ports on the