Abstract: System for monitoring stability of autonomous robot, including a GNSS navigation receiver including antenna, analog front end, plurality of channels, inertial measurement unit (IMU) and a processor, all generating navigation and orientation data for the robot; based on the navigation and orientation data, calculating position and direction of movement for the robot; calculating spatial and orientation coordinates z1, z2 of the robot, relating to the position and direction of movement; continuing with programmed path for the robot for any spatial and orientation coordinates z1, z2 within an attraction domain, where a measure V(z) of distance from zero in z1, z2 plane are defined by Lurie-Postnikov functions and is less than 1; for spatial and orientation coordinates outside the attraction domain with V(z)>1, terminating the programmed path and generating notification.

Abstract: System for navigating to a trajectory starting point by autonomous robot includes a GNSS navigation receiver including antenna, analog front end, plurality of channels, and a processor, generating navigation and orientation data for the robot; based on the navigation and the orientation data, the system calculating a position and a direction of movement for the robot towards the starting point of the trajectory, given known physical constraints for movement of the robot; the system calculating spatial and orientation coordinates z1, z2 of the robot, which relate to the position and the direction of movement, where z1 represents lateral deviation, and z2 represents angular deviation; the system continuing with a programmed path for the robot for any spatial and orientation coordinates z1, z2 within an attraction domain; and for any spatial and orientation coordinates of the robot outside the attraction domain, the system continues maneuvering until the robot is inside the attraction domain.

Abstract: System for navigating to a trajectory starting point by autonomous robot includes a GNSS navigation receiver including antenna, analog front end, plurality of channels, and a processor, generating navigation and orientation data for the robot; based on the navigation and the orientation data, the system calculating a position and a direction of movement for the robot towards the starting point of the trajectory, given known physical constraints for movement of the robot; the system calculating spatial and orientation coordinates z1, z2 of the robot, which relate to the position and the direction of movement, where z1 represents lateral deviation, and z2 represents angular deviation; the system continuing with a programmed path for the robot for any spatial and orientation coordinates z1, z2 within an attraction domain; and for any spatial and orientation coordinates of the robot outside the attraction domain, the system continues maneuvering until the robot is inside the attraction domain.

Abstract: System for monitoring stability of an autonomous robot, including a GNSS navigation receiver including an antenna, an analog front end, a plurality of channels, an inertial measurement unit (IMU) and a processor, all generating navigation and orientation data for the robot; based on the navigation and the orientation data, calculating a position and a direction of movement for the robot; calculating spatial and orientation coordinates z1, z2 of the robot, which relate to the position and the direction of movement; continuing with a programmed path for the robot for any spatial and orientation coordinates z1, z2 within an attraction domain, such that a measure V(z) of distance from zero in a z1, z2 plane are defined by Lurie-Postnikov functions and is less than 1; and for any spatial and orientation coordinates outside the attraction domain with V(z)>1, terminating the programmed path and generating a notification.

Abstract: An antenna system includes a right-hand circularly polarized antenna for receiving Global Navigation Satellite System (GNSS) signals and located on a receiver housing; a vertical semitransparent screen for providing an Down/Up ratio DU 9 ? 0 = DU ? ( ? e = 9 ? 0 ? ) = F ? ( - 9 ? 0 ? ) F ? ( 9 ? 0 ? ) of ?13 dB or better for at least some GNSS frequencies; the semitransparent screen being connected to a ground plane of the antenna; the ground plane being connected to a conductive receiver housing; the semitransparent screen further comprising a horizontal slot to which sets of lumped impedance elements are connected. Each set includes several lumped elements; where the lumped elements are capacitors and/or inductors and/or resistors; where the lumped elements in each set are connected in parallel or series; and the semitransparent screen including at least 4 segments arranged symmetrically around the center of the antenna and connected to each other.

Abstract: An antenna system includes a right-hand circularly polarized antenna for receiving Global Navigation Satellite System (GNSS) signals and located on a receiver housing; a vertical semitransparent screen for providing an Down/Up ratio DU 9 ? 0 = DU ? ( ? e = 9 ? 0 ? ) = F ? ( - 9 ? 0 ? ) F ? ( 9 ? 0 ? ) of ?13 dB or better for at least some GNSS frequencies; the semitransparent screen being connected to a ground plane of the antenna; the ground plane being connected to a conductive receiver housing; the semitransparent screen further comprising a horizontal slot to which sets of lumped impedance elements are connected.

Abstract: An antenna system includes a circularly-polarized antenna element with a Down/Up ratio in a proximity of a local horizon of no better than ?12 dB. An antenna radome encloses the antenna element, the radome providing a drop of antenna pattern near a local horizon and having an upper transparent area and a lower semi-transparent area. The semi-transparent area is has a generally hemispherical shape. The semi-transparent area includes a circular metallized portion with vertical and horizontal slots, the metallized portion extending part of the way downward from an equator of the generally hemispherical shape. The metallized portion includes passive discrete electrical elements connected across at least some of the slots. The metallized portion can include multiple areas having different degrees of transparence. Each such area has a specified impedance. The discrete elements are capacitors, inductors and/or resistors. The metallized portion can have a plurality of circular rows separated by the horizontal slots.

Abstract: An antenna system includes a circularly-polarized antenna element with a Down/Up ratio in a proximity of a local horizon of no better than ?12 dB. An antenna radome encloses the antenna element, the radome providing a drop of antenna pattern near a local horizon and having an upper transparent area and a lower semi-transparent area. The semi-transparent area is has a generally hemispherical shape. The semi-transparent area includes a circular metallized portion with vertical and horizontal slots, the metallized portion extending part of the way downward from an equator of the generally hemispherical shape. The metallized portion includes passive discrete electrical elements connected across at least some of the slots. The metallized portion can include multiple areas having different degrees of transparence. Each such area has a specified impedance. The discrete elements are capacitors, inductors and/or resistors. The metallized portion can have a plurality of circular rows separated by the horizontal slots.