評論
打印
Adding threat-detection measures, such as heavy, power-hungry radar antennae, or spinning lidar units,
增加威脅探測措施，如重型耗電的雷達天線或旋轉激光雷達裝置
radar's optical equivalent, would either reduce range or prevent lift-off in the first place.
（雷達的光學等效裝置）可以在一開始就減少投擲射程或防止投擲。
Dr Roy and Mr Garg think, however, that they have hit on a low-power, lightweight self-defence system suitable for small drones.
但Roy博士和Garg博士認為他們發現了一種適用于小型無人機的低功率、輕型自衛系統。
Instead of employing light or radio waves to detect incoming threats, it harnesses sound waves and the Doppler effect.
無需光波和無線電波，它可以利用聲波和多普勒效應來探測威脅來襲。
The Doppler effect is the frequency shift heard as a source of sound approaches or recedes.
多普勒效應是當聲源靠近或后退時聽到的頻率偏移。
It is, for example, the reason the pitch of a police siren changes as a patrol car passes in the street.
例如，這就是警車在街上經過時警笛聲改變的原因。
To take advantage of it Dr Roy and Mr Garg plan to fit drones with diminutive loudspeakers, like those found in smartphones.
Roy博士和Garg博士計劃利用這一點給無人機裝上小型揚聲器，就像智能手機上的那樣。
These would broadcast an ultrasonic tone outward from the drone.
它們會從無人機向外發射超聲波。
Similarly tiny microphones would then listen for reflections from incoming objects.
類似的，小型麥克風會聽取來自臨近物體的反射。
The Doppler shift of these reflections, run through a bit of on-board processing
這些反射的多普勒頻移，經過一些機載處理
(but far less than that needed for radar or lidar) would give the bearing of the threat, and thus permit the drone to take evasive action.
（但遠遠少于雷達或激光雷達所需的處理），就能確定威脅的方位，從而使無人機采取規避行動。
To test the principle of what they call their DopplerDodge drone defence system,
為了測試他們的DopplerDodge無人機防御系統，
Dr Roy and Mr Garg have constructed a static version in their laboratory,
Roy博士和Garg博士在他們的實驗室里構建了一個靜態版本，
and have been throwing objects of various sizes and shapes at it, as if it were a hovering drone.
并向它投擲各種大小和形狀的物體，就好像它是一個在空中盤旋的無人機。
At the moment, it can detect these objects from distances of up to four metres away.
目前，它可以探測到4米以外的物體。
That is pretty close, but would still give a drone a tenth of a second's notice of an incoming missile.
這個距離很近，但是仍然可以給無人機十分之一秒的時間來注意臨近的投擲。
This would be sufficient for it to move itself out of the way.
這足以讓無人機避開。
Tests on actual drones will take place shortly, and then, if all goes as planned,
不久將進行無人機的實際測試，如果一切按計劃進行，
the two researchers will attempt to extend the system's range to 30 metres—a reasonable approximation of a stone's throw.
兩位研究人員將嘗試將系統的射程擴大到30米——一個接近扔石頭的合理距離。
譯文由可可原創，僅供學習交流使用，未經許可請勿轉載。
