Abstract: An object tracking device that can track an object accurately and consistently is provided. An object tracking device (20) includes an input interface (21), a processor (23), and an output interface (24). The input interface (21) is configured to acquire sensor data. The processor (23) is configured to detect a detection target from the sensor data and track the detection target using Kalman filters associated with each of the detection target and an observed value. The output interface (24) is configured to output a detection result regarding the detection target. The processor (23) is configured to impose a limit on a range of variation in an index of the Kalman filters that influences tracking of the detection target.

Abstract: The invention provides a process for industrially and advantageous production of methacrolein and methacrylic acid which comprises subjecting isobutylene or tert-butanol to gas phase catalytic oxidation with a molecular oxygen-containing gas in the presence of a catalyst having the composition represented by the following formula:Mo.sub.a W.sub.b Bi.sub.c Fe.sub.d Sb.sub.e Cr.sub.f Si.sub.g A.sub.h X.sub.i Y.sub.j Z.sub.k O.sub.