| 摘要 |
The system is used with a powered door, such as a passenger door in a bus (fig 2). Two ultrasonic sensors are provided at the door so that a first sensor emits a signal from the door frame top downwards (1 figs 1,2) and a second sensor emits a signal near the outside of the door to detect the external environment (2 figs 1,2). If the first sensor indicates that an object is at the door frame or the second sensor indicates that an object exists on the outer side of the door by comparison with a precious record, then the door is prohibited from being closed. Otherwise, the door can be closed. Figure 5 shows flow diagram including producing an alarm for the attention of the bus driver. |
