Automobile engine knock sensor based on fiber grating array

The invention discloses an automobile engine knock sensor based on a fiber bragg grating array, belongs to the technical field of fiber sensing and engine knock monitoring, and aims to solve the problem that an electronic sensor adopted by an existing knock sensor is easily interfered by electromagnetic interference, so that the measurement is inaccurate. The sensor comprises a shell, a rhombic structure elastomer, a fiber grating, an upper mass block, a lower mass block and a demodulation module, the upper mass block and the lower mass block are arranged above and below an inner cavity of the shell respectively, and the two ends of a vertical diagonal line of the rhombic structure elastomer are fixedly embedded in the upper mass block and the lower mass block respectively; the horizontal diagonal line of the rhombic structure elastomer clamps the fiber bragg grating, the tail end of the fiber bragg grating extends out of the shell, and the tail end of the fiber bragg grating is provided with a tail fiber; an