Abstract: The described aspects and implementations enable efficient calibration of a sensing system of an autonomous vehicle (AV). In one implementation, disclosed is a method and a system to perform the method, the system including the sensing system configured to collect sensing data and a data processing system, operatively coupled to the sensing system. The data processing system is configured to identify reference point(s) in an environment of the AV, determine multiple estimated locations of the reference point(s), and adjust parameters of the sensing system based on a loss function representative of differences of the estimated locations.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for using naturally collected data in sensor calibration. One of the methods includes obtaining, using a first, calibrated sensor, a first plurality of raw sensor measurements of an environment; determining, from the first plurality of raw sensor measurements, a Truncated Signed Distance Field (TSDF)-based model of surfaces in the environment; obtaining, using a second sensor, a second plurality of raw sensor measurements of the environment; determining a multi-dimensional point cloud representation of the environment; and determining refined values of the set of calibration parameters of the second sensor based on a difference between, for each data point, (i) the multiple values that define the data point and (ii) multiple values that define a target data point derived from the TSDF-based model of surfaces in the environment.

Abstract: A rotor is provided wherein an rotor core and a jacket cooperate to provide a continuous variation of area left for fluid transit. This continuous variation of area left for fluid transit produces a continuous axial acceleration of fluid and provides a first pressure gradient. The invention also provides simultaneously for blades having a continuously varying angle provided in the area left for fluid transit and causing a second pressure gradient. The varying of the fluid transit area and the angle of the blade are designed to have the first and second pressure gradients to be complementary and maintain the pressure of the fluid substantially constant. Such a continuous varying angle of inclination of the blades provides a continuous angular acceleration of the fluid and corresponding torque. The blades of continuously varying angle of inclination rotate together with the rotor core producing the torque.