US 11,768,278 B2
Lidar receiving apparatus, lidar system and laser ranging method
Shen Jiang, Shenzhen (CN)
Assigned to SUTENG INNOVATION TECHNOLOGY CO., LTD., Shenzhen (CN)
Appl. No. 17/264,544
Filed by SUTENG INNOVATION TECHNOLOGY CO., LTD., Shenzhen (CN)
PCT Filed Mar. 20, 2020, PCT No. PCT/CN2020/080350
§ 371(c)(1), (2) Date Jan. 29, 2021,
PCT Pub. No. WO2020/258933, PCT Pub. Date Dec. 30, 2020.
Claims priority of application No. 201910576631.0 (CN), filed on Jun. 28, 2019.
Prior Publication US 2021/0311174 A1, Oct. 7, 2021
Int. Cl. G01S 7/48 (2006.01); G01S 7/4861 (2020.01); G01S 7/487 (2006.01); G01S 7/489 (2006.01); G01S 17/10 (2020.01)
CPC G01S 7/4861 (2013.01) [G01S 7/487 (2013.01); G01S 7/489 (2013.01); G01S 17/10 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A lidar receiving apparatus, comprising:
a photodetector, which is configured to receive a reflected laser signal and to convert the reflected laser signal into a current signal when a bias voltage of the photodetector is greater than a breakdown voltage of the same;
a reference photodetector, which is in a light-shielded state, and is connected in parallel with the photodetector; and
a ranging circuit, which is connected with the photodetector, and configured to control the bias voltage applied to the photodetector according to a predefined rule;
wherein the predefined rule comprises: at a receiving time of a stray reflected signal, the bias voltage of the photodetector is smaller than the breakdown voltage; and the receiving time of the stray reflected signal is a time at which a transmitted laser signal reaches the photodetector through a stray light path other than a ranging light path, and is correlated to a preset flight time of the stray reflected signal, and
wherein the ranging circuit comprises:
a cancelling and trans-impedance amplifying circuit, which is connected with the photodetector and the reference photodetector, respectively, and configured to perform cancellation and trans-impedance amplification on both current signals output from the photodetector and the reference photodetector, and output voltage signals obtained after the cancellation and the trans-impedance amplification are performed, wherein the current signal output from the reference photodetector is positively correlated to the bias voltage applied to the reference photodetector; and
a second processing circuit, which is connected with the cancelling and trans-impedance amplifying circuit, and configured to calculate the distance data according to the voltage signals obtained after the cancellation and the trans-impedance amplification are performed.