Target information measuring device with high possible accuracy of measured information

摘要

Target information measuring device, having:a transceiver module (10, 10A, 20, 20A) which transmits multiple signal pulses for each predetermined measurement cycle and receives multiple echoes based on the multiple signal pulses to obtain multiple received signals, each representing an intensity of one corresponding to the multiple echoes;a first measuring module (321, 131) which:measures for each measurement cycle a first elapsed time between a transmission time of a signal pulse in the plurality of signal pulses and a first time, wherein the first time is a time when a level of a received signal according to that of a signal pulse passes a predetermined limit level, where the received signal is defined as a signal received from the target; andobtains a first measurement based on the first elapsed time representing distance information to a target starting from the target information measuring device, wherein the target generates an echo based on the one signal pulse corresponding to the signal received from the target;a second measuring module (322, 132) which:for each measurement cycle, scan each of the multiple signals received at predetermined sampling intervals to obtain sampled levels for each of the multiple signals received;extracts several sets of sampled levels, the sampled levels of each of the multiple sets corresponding to the multiple received signals, and the sampling times of the sampled levels of each of the multiple sets have an identical elapsed time with respect to the transmission time of one corresponding to the plurality of signal pulses;integrated the sampled levels from each of the multiple sets with each other to obtain multiple integrated sampled levels to obtain a second measurement based on the multiple integrated sampled levels representing the distance information to the target starting from the target information measuring device;a determination device (40, 40A) determining how the first measurement and/or the second measurement are to be used to definitively determine a distance of the target according to a parameter, the parameter having a correlation with an intensity of at least one of the multiple echoes; anda speed calculator (40, 40A, S190 to S220) configured to calculate for each measurement cycle a speed of the target according to the final distance of the target,where the first measurement module is configured to:have a first limit level higher than a predetermined noise level and a second limit level higher than the first limit level than the limit level;for each measurement cycle, measure the first elapsed time between the transmission time of one signal pulse and the first time using the second limit level as the limit level if the level of the signal received from the target is higher than the second limit level; andfor each measurement cycle, measure the first elapsed time between the transmission time of one signal pulse and the first time using the first limit level as the limit level if the level of the signal received from the target is equal to or less than the second limit level; andwherein the determination device is configured to use the first measurement when the level of the signal received from the target representing the parameter is higher than the second limit level to definitively determine the distance of the target, use the second measurement when the level of the signal received from the target, which represents the parameter is lower than the first limit level in order to definitively determine the distance of the target and to use an average of the first measurement and the second measurement, if the level of the signal received from the target is equal to or greater than the first limit level and equal to or less than the second limit level;to definitively determine the distance of the target.