Rockwell Automation Technologies Incorporated

Frederic Boutaud

Mei Li

Suresh Ramanujan Nair

Richard Galera

Michael M Tilleman

Chris Softley

Chris Yates

Donald Lee Charlantini

Derek Washington Gallon

Igor Abrosimov

Gregory J Reimann

Arvind Ananthanaraya

Derek William Jones

Rudolf Papenbreer

Burt Sacherski

Martin Hardegger

Christopher Burke

Lin Wang

Linda A Freeman

James Feng Sun

Kentaro Sugimoto

David M O'Brien

Chris John Yates

Derek W Gallon

A safety system for autonomously mobile machinery (e.g., automated guided vehicles) achieves safety-rated collision avoidance functionality by detecting objects located in the field of view of a three-dimensional (3D) time-of-flight (TOF) vision system or camera. Incorporating a 3D TOF camera into a collision avoidance system allows a large volume to be monitored for object intrusion, improving reliability of object detection. To ensure reliability of the safety system's obstacle detection capabilities, the collision avoidance system also includes self-diagnostic capabilities that verify the accuracy of the TOF camera's distance measurements even in the absence of a test object within the camera's field of view. This is achieved by tilting the TOF camera downward to include the floor within the camera's field of view, allowing the floor to act as a test object that can be leveraged to verify accuracy of the camera's distance measurements.

Time of flight system and method for safety-rated collision avoidance

A time of flight sensor device is capable of generating accurate propagation time information for emitted light pulses using a small number of measurement cycles by using multiple measuring capacitors to capture more return pulse information per pulse period. To mitigate the effects of mismatched measuring capacitors and reading paths, embodiments of the time of flight sensor device perform multiple measuring sequences per measurement operation, permutating the roles of the measuring capacitors for each of the measuring sequences. The data collected by the measuring capacitors for the multiple measuring sequences is then aggregated and used to compute the propagation time and corresponding distance. This technique mitigate yields accurate measurements despite mismatches between reading paths and measuring capacitors without the need to implement pixel-level calibration and compensation, thereby saving calibration time, memory space, and computing time.

Permutation of measuring capacitors in a time-of-flight sensor

A time of flight sensor device is capable of extending its total sensing distance using multiple measuring sequences for each distance measuring operation. Such embodiments can execute two or more iterations of a measuring sequence, where the gating signal control sequence for each measuring sequence is offset in time relative to a previous sequence. This yields a greater number of sampling points within which a reflected pulse can be detected and measured, resulting in a total measurable time of flight range that is greater than a measuring operation that uses a fixed timing for the gating signals.

Time of flight system and method using multiple measuring sequences

A time of flight (TOF) sensor device employs a measuring sequence that facilitates accurate distance measurement across a high dynamic range. In one or more embodiments, for a given measuring sequence in which a distance of an object or surface corresponding to a pixel is to be determined, the TOF sensor device performs multiple iterations of a measuring cycle, whereby for each successive iteration the number of emitted and measured pulses that are accumulated for the iteration is increased relative to the previous iteration of the measuring cycle. In this way, multiple values of increasing resolution are measured for the same physical entity over a corresponding number of measuring cycles. The sensor then selects a value from the multiple measured values that yields the highest resolution without saturating the pixel, and this value is used to determine the pulse propagation time and object distance.

High dynamic range for sensing systems and methods

An active illumination three-dimensional sensor device is configured with a number of diagnostic functions that can satisfy the requirements of industrial safety within the context of a single-channel safety sensor architecture. The sensor diagnostic functions provide sufficient diagnostic coverage for an optical safety sensor (e.g., a time-of-flight safety sensor) to achieve a desired safety integrity level without the need for multiple channels. The diagnostic features can be applied to one or more components along the single-channel path (e.g., the sequencer, the illumination source, input and/or output optics, image sensor pixel, etc.) to provide a level of diagnostic coverage that renders the optical safety sensor suitable for use within industrial safety applications requiring high safety integrity levels.

Industrial safety sensor

A three-dimensional (3D) sensor device achieves accurate distance measurements in the presence of multipath illumination interference (MPII) by estimating the effect of indirect illumination on a given pixel's optical signal measurement and correcting the signal measurement to remove the estimated contribution from indirect illumination. After generating an initial point cloud image of a scene, the sensor device identifies target objects and background objects within the scene, where the background objects are potential sources of indirect illumination. The sensor device estimates the total amount of indirect illumination directed to a point on the target object by the background objects and received at a pixel corresponding to the point, and corrects the measured signal at the pixel to remove the contribution of this estimated indirect illumination. The sensor device performs this MPII estimation without a priori knowledge of the background objects' characteristics, and is therefore response to changes in the background.

Multipath interference error correction in a time of flight sensor

A three-dimensional (3D) sensor device achieves high intrusion detection probability while keeping the probability of a false intrusion detection low by capturing a set of multiple spatial or temporal samples of a measured parameter for an object detected in the sensor's field of view. When an object is detected in the field of view, the TOF sensor device defines a window of N pixels comprising a subset of the pixels corresponding to the object, and obtains N distance measurements corresponding to the N pixels of the window. If the number of the N distance values that are less than a defined threshold distance is equal to or greater than a selected threshold value M (an integer less than N), the TOF sensor device determines that the object is intruding within a protective field and generates a suitable output.

Object intrusion detection system and method

A time of flight sensor device is provided that is capable of generating accurate information relating to propagation time of emitted light pulses using a small number of measurements or data captures. By generating pulse time of flight information using a relatively small number of measurement cycles, object distance information can be generated more quickly, resulting in faster sensor response times. Embodiments of the time of flight sensor can also minimize or eliminate the adverse effects of ambient light on time of flight measurement. Moreover, some embodiments execute time of flight measurement techniques that can achieve high measurement precision even when using relatively long light pulses having irregular, non-rectangular shapes.

Pulsed-based time of flight methods and system

Systems and techniques for determining sensing margins and/or diagnostic information associated with a sensor are presented. A statistics component generates statistical data based on sensor data associated with a sensing device. A margin component generates sensing margins for the sensing device based on the statistical data. An output component generates an indicator for a changing condition associated with the sensing device based on the sensing margins. In an aspect, a diagnostic component generates diagnostic data for the sensing device based on the statistical data.

System and method for determining sensor margins and/or diagnostic information for a sensor

An energy-efficient industrial sensor is provided that optimizes power consumption based on characteristics of the requirements of the sensing application in which the sensor is used. Operating parameters of the sensor, such as sensing range, operating frequency, response time, noise immunity, or other such parameters, can be scaled to suit the sensing and response requirements and environmental conditions of the sensing application. This allows the sensor to consume less energy when used in sensing applications that do not require peak sensor performance. In some embodiments, the sensor can measure the environmental or machine operating conditions in its immediate vicinity and dynamically scale its operating parameters based on the measured information. By down-scaling the sensor's operating parameters from their maximum performance levels where appropriate, the overall energy footprint of a network of sensors can be reduced.

Application-based power consumption optimization for sensing devices

A bobbin and coil architecture is provided for use in an inductive sensor. The architecture eliminates the need for coil shielding and reduces the sensor's sensitivity to temperature and proximate mounting hardware. In one or more embodiments, all or portions of separate coils are located in a common slot on the bobbin, rather than being segregated into separate slots. In an example configuration, two receiver coils may be located in respective two slots on the bobbin, and a transmitter coil may divided into two substantially equal subsets of windings, with each subset wound together with one of the receiver coils in a common slot. This yields a symmetrical and balanced winding architecture that requires fewer slots relative to designs that segregate all coils into separate slots.

Coil architecture for inductive sensors

A photoelectric sensor uses a selective pulse detection technique and associated synchronization techniques to improve the quality of pulse detection, the operating range of the sensor, and the sensor's immunity to noise. These improvements also yield faster sensor response times and reduce the design cycle time. A modulated light beam emitted by the sensor's emitter comprises multiple pulse periods, with a pulse being transmitted within each period. The pulses are positioned within their respective periods at a defined offset time relative to the start of the periods, where the offset time can vary between periods according to a defined pattern. The receiver can selectively sample the signal based on synchronization information to determine whether the received signal contains the emitted pulse pattern. Through-beam sensor embodiments can generate the synchronization information internally based on an analysis of the analog signal corresponding to the modulated signal.

Growing community of inventors

Lexington, MA, United States of America

Frederic Boutaud