All weather visual system for helicopters

• US 5,614,907 A
• Filed: 03/14/1996
• Issued: 03/25/1997
• Est. Priority Date: 03/14/1996
• Status: Expired due to Term

• Current Assignee: Daimler-Benz Aerospace AG (Mercedes-Benz Group AG)
• Original Assignee: Daimler-Benz Aerospace AG (Mercedes-Benz Group AG)
• Inventors: Kreitmair-Steck, Wolfgang, Klausing, Helmut
• Primary Examiner(s): Sotomayor, John B.
• Application Number:
  US08/616,003
• Time in Patent Office: 376 Days
• Field of Search: 342/25, 342/55, 342/66, 342/179, 342/197
• US Class Current: 342/25.00F
• CPC Class Codes: G01C 15/14 Artificial horizons
• CPC Class Codes: G01S 13/86 Combinations of radar systems with non-radar systems, e.g. sonar, direction finder
• CPC Class Codes: G01S 13/9082 Rotating SAR [ROSAR]

Abstract

The invention relates to an all weather visual system that combines information from a ROSAR type radar sensor with navigation and flight information to provide artificial vision for the pilot. The radar utilizes the movements of rotating arms fixedly mounted on the rotor head of a helicopter. For this purpose, a turnstile is used as the central carrier structure, which is protected by an aerodynamically shaped body against atmospheric forces. The radar transmitter and radar receiver are located on the rotor head and in the tips of the rotating arms, respectively.

Claims

1. All weather visual system for a helicopter, of the type comprising a synthetic aperture radar unit with rotating antennas, in which at least one radar antenna is located at the end of a helicopter rotor or a turnstile above a rotor axis, to transmit and receive radar pulses, received signals being demodulated, temporarily stored, correlated in a computer, and then displayed, wherein:

radar antennas are positioned between the rotor blades in one of;

a single plane, and planes that overlap one another pairwise;

transmitting and receiving antenna pairs with different elevational directions are integrated in the ends of rotating antenna support arms;

radar transmitting/receiving electronics in the rotating antenna support arms and in a co-rotating electronics housing are integrated with a power supply;

acceleration sensors coupled to provide inputs to said computer for motion compensation;

means for measuring the forward speed are coupled to provide inputs to said computer;

precision gyros are provided to locate the rotational plane of the antenna support arms, said precision gyros also being coupled to provide inputs to said computer; and

means coupled to an output of said computer are provided for displaying radar information as a photo-like image on a screen located in the cockpit, partial images from the antennas with different elevation angles being linked and smoothed to create said images.

2. All weather visual system according to claim 1 wherein the radially directed radar antennas are aerodynamically shaped.

3. All weather visual system according to claim 1 wherein antennas are provided with an aerodynamic shroud.

4. All weather visual system according to claim 1 wherein the receiving electronics in the centrally located electronics compartment or in the antenna support arms processes radar signals as intermediate frequency (IF) signals and conducts them through the rotor shaft by means of a rotary coupler to the radar processor.

5. All weather visual system according to claim 2 wherein the receiving electronics in the centrally located electronics compartment or in the antenna support arms processes radar signals as intermediate frequency (IF) signals and conducts them through the rotor shaft by means of a rotary coupler to the radar processor.

6. All weather visual system according to claim 1 wherein analog or analog/digital data transfer is performed by means of one of the following:

optical fibers, coaxial electric cables, and hollow waveguides.

7. All weather visual system according to claim 1 wherein forward speed of the helicopter is determined autonomously by Doppler evaluation of the emitted radar signal for motion compensation, and the position of the rotational plane is determined by one of the following:

precision gyros located at the center of the rotor head axis, and an on-board navigation gyro.