Flash ladar collision avoidance system

A robotic driving system adapted to steer a vehicle autonomously comprising:

• at least one ladar sensor mounted to the vehicle and,
• a system controller,
• and the ladar sensor connected to said system controller via bidirectional connections, the bidirectional connections comprising;
• a cable assembly routed through the vehicle, the cable assembly further comprising;
• a first end connected to the system controller, and
• a connector at a second end adapted to connect to the ladar sensor;
• and the ladar sensor having a field of view, and housed within an envelope and mounted to the vehicle, said envelope having a device connector adapted to mate with the cable assembly, and the envelope having a transparent surface adapted to transmit infrared light;
• said ladar sensor further comprising,
• a pulsed laser transmitter having a transmission wavelength, and a pulsed light output and diffusing optic, and is adapted to emit a laser light pulse to illuminate a scene in the field of view, and
• a time zero reference circuit having a time zero output, said time zero output adapted to signal the instant of emission of the laser light pulse,
• a receiving lens assembly having an optical transmission path, and adapted to collect and focus light reflected from the scene,
• an optical bandpass filter positioned in the optical transmission path of the receiving lens assembly, and adapted to transmit light at the wavelength of transmission, and to block other wavelengths of light,
• a regular geometric array of light sensitive detectors positioned at a focal point of the light collecting and focusing lens, and each light sensitive detector having an output terminal producing an electrical pulse when illuminated by a reflected portion of the laser light pulse,
• a readout integrated circuit comprised of a regular geometric array of unit cell electrical circuits, and each unit cell electrical circuit having an input connected to the output terminal of a light sensitive detector,
• and each unit cell electrical circuit adapted to amplify and detect said electrical pulse, and the unit cell electrical circuit having a detected pulse output, and
• a plurality of timing circuits, and each timing circuit connected to a detected pulse output, and also connected to the time zero output, and
• said timing circuit having an elapsed time output, and producing an elapsed time value indicating the time delay between the emission of the laser light pulse and the detected pulse output from the associated unit cell electrical circuit,
• and said readout integrated circuit connected to a plurality of the elapsed time outputs, and the readout integrated circuit adapted to collect and transmit via the cable assembly the elapsed time values,
• and said system controller further having a digital processor adapted to make an optimum path computation, and the system controller also having a control output connected to the vehicle steering, and thereby navigating the vehicle.

A ladar sensor comprising:

• a laser transmitter configured to produce a pulsed light output at a wavelength of transmission;
• a diffusing optic coupled to the laser transmitter to receive and diffuse the pulsed light output and illuminate a scene in a field of view;
• a time zero reference circuit generating a time zero output, the time zero output adapted to signal an instant of emission of the pulsed light output;
• a receiving lens assembly configured to collect and focus light reflected from the scene;
• an optical bandpass filter disposed in the receiving lens assembly and configured to transmit light reflected from the scene at the wavelength of transmission while blocking other wavelengths of light;
• a plurality of light sensitive detectors positioned to receive the light reflected from the scene, wherein each light sensitive detector produces an electrical signal when illuminated by the light reflected from the scene;
• a readout integrated circuit comprising a plurality of unit cell electrical circuits, each unit cell electrical circuit coupled to one of the light sensitive detectors and configured to amplify and detect the electrical signal from the light sensitive detector and provide a detected pulse output;
• each unit cell electrical circuit also comprising a timing circuit in communication with the time zero output and configured to produce an elapsed time measurement value indicating the time delay between the emission of the pulsed light output and the electrical signal indicated by the detected pulse output,
• the readout integrated circuit configured to collect and transmit the elapsed time measurement values from the timing circuits.