3569 results about "Inertial measurement unit" patented technology

A pipeline inspection and defect mapping system includes a pig having an inertial measurement unit and a pipeline inspection unit for recording pig location and defect detection events, each record time-stamped by a highly precise onboard clock. The system also includes several magloggers at precisely known locations along the pipeline, each containing a fluxgate magnetometer for detecting the passage of the pig along the pipeline and further containing a highly precise clock synchronized with the clock in the pig. The locations of the various magloggers are known in a north / east / down coordinate system through a differential global positioning satellite process. Finally, a postprocessing off-line computer system receives downloaded maglogger, inertial measurement, and odometer data and through the use of several Kalman filters, derives the location of the detected defects in the north / east / down coordinate frame. Consequently, a task of identifying sites for repair activity is much simplified.

An interruption-free hand-held positioning method and system, carried by a person, includes an inertial measurement unit, a north finder, a velocity producer, a positioning assistant, a navigation processor, a wireless communication device, and a display device and map database. Output signals of the inertial measurement unit, the velocity producer, the positioning assistant, and the north finder are processed to obtain highly accurate position measurements of the person. The user's position information can be exchanged with other users through the wireless communication device, and the location and surrounding information can be displayed on the display device by accessing a map database with the person position information.

A self-contained, integrated micro-cube-sized inertial measurement unit is provided wherein accuracy is achieved through the use of specifically oriented sensors, the orientation serving to substantially cancel noise and other first-order effects, and the use of a noise-reducing algorithm such as wavelet cascade denoising and an error correcting algorithm such as a Kalman filter embedded in a digital signal processor device. In a particular embodiment, a pair of three sets of angle rate sensors are orientable triaxially in opposite directions, wherein each set is mounted on a different sector of a base orientable normal to the other two and comprising N gyroscopes oriented at 360 / N-degree increments, where N≧2. At least one accelerometer is included to provide triaxial data. Signals are output from the angle rate sensors and accelerometer for calculating a change in attitude, position, angular rate, acceleration, and / or velocity of the unit.

A method and system for providing an optical see-through Augmented Reality modified-scale display. This aspect includes a sensor suite 100 which includes a compass 102, an inertial measuring unit 104, and a video camera 106 for precise measurement of a user's current orientation and angular rotation rate. A sensor fusion module 108 may be included to produce a unified estimate of the user's angular rotation rate and current orientation to be provided to an orientation and rate estimate module 120. The orientation and rate estimate module 120 operates in a static or dynamic (prediction) mode. A render module 140 receives an orientation; and the render module 140 uses the orientation, a position from a position measuring system 142, and data from a database 144 to render graphic images of an object in their correct orientations and positions in an optical display 150.

An improved fully-coupled vehicle positioning process and system thereof can substantially solve the problems encountered in global positioning system-only and inertial navigation system-only, such as loss of global positioning satellite signal, sensibility to jamming and spoofing, and inertial solution's drift over time, in which the velocity and acceleration from an inertial navigation processor are used to aid the code and carrier phase tracking of the global positioning system satellite signals, so as to enhance the performance of the global positioning and inertial integration system, even in heavy jamming and high dynamic environments. The improved fully-coupled GPS / IMU vehicle positioning system includes an IMU (inertial measurement unit) and a GPS processor which are connected to a central navigation processor to produce navigation solution that is output to an I / O (input / output) interface.

A system for allowing an operator to switch between remote vehicle tele-operation and one or more remote vehicle autonomous behaviors. The system comprises: an operator control unit receiving input from the operator including instructions for the remote vehicle to execute an autonomous behavior; a control system on the remote vehicle for receiving the instruction to execute an autonomous behavior from the operator control unit; and a GPS receiver, an inertial measurement unit, and a navigation CPU on the remote vehicle. Upon receiving the instruction to execute an autonomous behavior, the remote vehicle executes that autonomous behavior using input from the GPS receiver, the inertial measurement unit (IMU), and the navigation CPU.

A micro integrated Global Positioning System (GPS) / Inertial Measurement Unit (IMU) System, which is adapted to apply to output signals proportional to rotation and translational motion of a carrier and GPS measurements of the carrier, respectively from angular rate sensors, acceleration sensors, and GPS chipset, is employed with MEMS angular rate and acceleration sensors and GPS chipset. Compared with a conventional IMU / GPS system, the system of the present invention uses an integrated processing scheme by means of digital closed loop control of the dither driver signals for MEMS angular rate sensors, a feedforward open-loop signal processing scheme of the IMU, digital temperature control and compensation, the earth's magnetic field-based heading damping, robust error estimator, and compact sensor and circuit architecture and dramatically shrinks the size of mechanical and electronic hardware and power consumption, meanwhile, obtains highly accurate motion measurements.

An interruption free navigator includes an inertial measurement unit, a north finder, a velocity producer, a positioning assistant, a navigation processor, an altitude measurement, an object detection system, a wireless communication device, and a display device and map database. Output signals of the inertial measurement unit, the velocity producer, the positioning assistant, the altitude measurement, the object detection system, and the north finder are processed to obtain highly accurate position measurements of the person. The user's position information can be exchanged with other users through the wireless communication device, and the location and surrounding information can be displayed on the display device by accessing a map database with the person position information.

An interruption free navigator includes an inertial measurement unit, a north finder, a velocity producer, a positioning assistant, a navigation processor, an altitude measurement, an object detection system, a wireless communication device, and a display device and map database. Output signals of the inertial measurement unit, the velocity producer, the positioning assistant, the altitude measurement, the object detection system, and the north finder are processed to obtain highly accurate position measurements of the person. The user's position information can be exchanged with other users through the wireless communication device, and the location and surrounding information can be displayed on the display device by accessing a map database with the person position information.

A Micro Inertial Measurement Unit (IMU) which is based on MEMS accelerometers and gyro sensors is developed for real-time recognition of human hand motions, especially as used in the context of writing on a surface. Motion is recorded by a motion / acceleration sensor, which may be a combination of a rate rate gyro and an accelerometer, and possibly in combination with a video camera set to detect markers located on a board, with the camera utilizable to detect lines and markers and to determine the proximity of the white board. The immediate advantage is the facilitation of a digital interface with both PC and mobile computing devices and perhaps to enable wireless sensing.

Systems and methods for sensing human muscle action and gestures in order to control machines or robotic devices are disclosed. One exemplary system employs a tight fitting sleeve worn on a user arm and including a plurality of electromyography (EMG) sensors and at least one inertial measurement unit (IMU). Power, signal processing, and communications electronics may be built into the sleeve and control data may be transmitted wirelessly to the controlled machine or robotic device.

The invention discloses a positioning method and system based on visual inertial navigation information fusion. The method comprises steps as follows: acquired sensor information is preprocessed, wherein the sensor information comprises an RGB image and depth image information of a depth vision sensor and IMU (inertial measurement unit) data; external parameters of a system which the depth visionsensor and an IMU belong to are acquired; the pre-processed sensor information and external parameters are processed with an IMU pre-integration model and a depth camera model, and pose information isacquired; the pose information is corrected on the basis of a loop detection mode, and the corrected globally uniform pose information is acquired. The method has good robustness in the positioning process and the positioning accuracy is improved.

Golf clubs having an embedded inertial measurement unit and a corresponding microprocessor for determining the motion of the head of the golf club. Briefly described, one of a number of embodiments of a golf club comprises a 6DOF inertial measurement unit disposed within the head of the golf club and a microprocessor in communication with the 6DOF inertial measurement unit. The microprocessor is configured to receive data from the 6DOF inertial measurement unit and determine the motion of the head of the golf club.

A position measurement system for measuring a position of an object is described, the system including: a first incremental measurement unit for measuring a first number of first distance steps in a distance between a reference frame and the object, wherein the first number equals a first integer value plus a first fraction, and a second incremental measurement unit for measuring a second number of second distance steps in a distance between the reference frame and the object, wherein the second number equals a second integer value plus a second fraction, wherein the position measurement system is constructed and arranged to initialize the second incremental measurement unit on the basis of the first number and the second fraction.

A real-time integrated vehicle positioning method and system with differential GPS can substantially solve the problems encountered in either the global positioning system-only or the inertial navigation system-only, such as loss of global positioning satellite signal, sensitivity to jamming and spoofing, and an inertial solution's drift over time. In the present invention, the velocity and acceleration from an inertial navigation processor of the integrated GPS / INS system are used to aid the code and carrier phase tracking of the global positioning system satellite signals, so as to enhance the performance of the global positioning and inertial integration system, even in heavy jamming and high dynamic environments. To improve the accuracy of the integrated GPS / INS navigation system, phase measurements are used and the idea of the differential GPS is employed. However, integer ambiguities have to be resolved for high accuracy positioning. Therefore, in the present invention a new on-the-fly ambiguity resolution technique is disclosed to resolve double difference integer ambiguities. The real-time fully-coupled GPS / IMU vehicle positioning system includes an IMU (inertial measurement unit), a GPS processor, and a data link which are connected to a central navigation processor to produce a navigation solution that is output to an I / O (input / output) interface.

A system and method for efficiently locating in 3D an object of interest in a target scene using video information captured by a plurality of cameras. The system and method provide for multi-camera visual odometry wherein pose estimates are generated for each camera by all of the cameras in the multi-camera configuration. Furthermore, the system and method can locate and identify salient landmarks in the target scene using any of the cameras in the multi-camera configuration and compare the identified landmark against a database of previously identified landmarks. In addition, the system and method provide for the integration of video-based pose estimations with position measurement data captured by one or more secondary measurement sensors, such as, for example, Inertial Measurement Units (IMUs) and Global Positioning System (GPS) units.

A method and apparatus for providing three-dimensional navigation for a node comprising an inertial measurement unit for providing gyroscope, acceleration and velocity information (collectively IMU information); a ranging unit for providing distance information relative to at least one reference node; at least one visual sensor for providing images of an environment surrounding the node; a preprocessor, coupled to the inertial measurement unit, the ranging unit and the plurality of visual sensors, for generating error states for the IMU information, the distance information and the images; and an error-state predictive filter, coupled to the preprocessor, for processing the error states to produce a three-dimensional pose of the node.

In one embodiment of the present invention, a method of and apparatus for determining inaccurate GPS samples in a set of GPS samples is disclosed, according to the following actions: a) obtaining GPS samples as taken by a global positioning system on board a vehicle when traveling along a trajectory; b) obtaining a first estimation of the trajectory based on the GPS samples; c) obtaining a second estimation of the trajectory at least based on measurements made by an inertial measurement unit on board vehicle when traveling along the trajectory; d) comparing the first and second estimations; e) establishing locations where the first estimation shows a variation compared with the second estimation above a predetermined threshold; f) if no such locations can be established continue with action j), otherwise continue with action g); g) removing GPS samples associated with the locations of high variation as being inaccurate GPS samples, thus forming a set of remaining GPS samples; h) calculating the first estimation anew of the trajectory based on the remaining GPS samples and calculating the second estimation anew; i) repeating actions d) to h); j) ending the actions.

A receiver for continuous carrier phase tracking of low carrier-to-noise ratio (“CNR”) signals from a plurality of radio navigation satellites while the receiver is mobile. The receiver may have: a radio frequency (RF) front-end that provides satellite data corresponding to signals received from the plurality of radio navigation satellites; an inertial measurement unit (IMU) that provides inertial data; and a processor circuit in circuit communication with the RF front end and the IMU, the processor circuit being capable of using satellite data from the RF front-end and inertial data from the IMU to perform continuous carrier phase tracking of low CNR radio navigation satellite signals having a CNR of about 20 dB-Hz, while the receiver is mobile. The receiver may be a GPS receiver for continuous carrier phase tracking of low-CNR GPS signals.

A virtual reality (VR) console receives slow calibration data from an imaging device and fast calibration data from an inertial measurement unit on a VR headset including a front and a rear rigid body. The slow calibration data includes an image where only the locators on the rear rigid body are visible. An observed position is determined from the slow calibration data and a predicted position is determined from the fast calibration data. If a difference between the observed position and the predicted position is greater than a threshold value, the predicted position is adjusted by a temporary offset until the difference is less than the threshold value. The temporary offset is removed by re-calibrating the rear rigid body to the front rigid body once locators on both the front and rear rigid body are visible in an image in the slow calibration data.

Vehicle-mounted device includes an inertial measurement unit (IMU) having at least one accelerometer or gyroscope, a GPS receiver, a camera positioned to obtain unobstructed images of an area exterior of the vehicle and a control system coupled to these components. The control system re-calibrates each accelerometer or gyroscope using signals obtained by the GPS receiver, and derives information about objects in the images obtained by the camera and location of the objects based on data from the IMU and GPS receiver. A communication system communicates the information derived by the control system to a location separate and apart from the vehicle. The control system includes a processor that provides a location of the camera and a direction in which the camera is imaging based on data from the IMU corrected based on data from the GPS receiver, for use in creating the map database.

A GNSS integrated multi-sensor guidance system for a vehicle assembly includes a suite of sensor units, including a global navigation satellite system (GNSS) sensor unit comprising a receiver and an antenna. An inertial measurement unit (IMU) outputs vehicle dynamic information for combining with the output of the GNSS unit. A controller with a processor receives the outputs of the sensor suite and computes steering solutions, which are utilized by vehicle actuators, including an automatic steering control unit connected to the vehicle steering for guiding the vehicle. The processor is programmed to define multiple behavior-based automatons comprising self-operating entities in the guidance system, which perform respective behaviors using data output from one or more sensor units for achieving the behaviors. A GNSS integrated multi-sensor vehicle guidance method is also disclosed.

The invention discloses a stable motion tracking method and a stable motion tracking device based on integration of a simple camera and an IMU (inertial measurement unit) of a smart cellphone, and belongs to the technical field of AR (augmented reality) / VR (virtual reality) motion tracking. The method includes processing an acquired image according to an ORB (object request broker) algorithm, performing 3D (three-dimensional) reconstruction to obtain initial map points, and completing map initialization; performing visual tracking through ORB algorithm real-time matching and parallel partial keyframe mapping to obtain a visual pose; acquiring accelerated velocity and angular velocity, both generated in a three-dimensional space, of the IMU, and performing integral operation on the accelerated velocity and the angular velocity to obtain an IMU pose prediction result; performing Kalman fusion on the visual pose and the IMU pose prediction result, and performing motion tracking according to pose information acquired after fusion. Compared with the prior art, the stable motion tracking method and the stable motion tracking device have the advantages that a stable motion tracking mode can be acquired and real-time online dimension estimation can be achieved.

The invention provides an unscented Kalman filter-based method for tracking an inertial pose according to acceleration compensation, which is used for an inertial measurement unit integrating a three-axis micro-gyroscope, a three-axis micro-accelerometer and a three-axis magnetoresistive sensor, and realizes pose tracking estimation on a device carrier by using rotary angular velocity vectors, acceleration vectors and magnetic field sensor vectors which are detected by the device by means of filter technology. The method comprises the following steps: 1) treating the acceleration vectors as combination of the acceleration vectors and gravity acceleration vectors of the device carrier self, and constructing observation equations respectively for amplitude and normalized direction vectors of the acceleration vectors and the gravity acceleration vectors; 2) describing quaternion, accumulated error vectors of the gyroscope and the acceleration vectors of the device carrier self by using the pose to construct a system state vector; and 3) realizing a filter estimating process of the system by using the unscented Kalman filter technology because of nonlinearity of the observation equations. Compared with the conventional method ignoring the acceleration of the carrier self, the method not only can provide a more accurate estimation result, but also widens the application range of the system.

A Micro Inertial Measurement Unit (IMU) which is based on MEMS accelerometers and gyro sensors is developed for real-time recognition of human hand motions, especially as used in the context of writing on a surface. Motion is recorded by a rate gyro and an accellerometer and communicated to a Bluetooth module, possibly to a computer which may be 20 to 30 feet or more from the sensor. The motion information generated and communicated is combined with appropriate filtering and transformation algorithms to facilitate a complete Digital Writing System that can be used to record handwriting on any surface, or on no surface at all. The overall size of an IMU can be less than 26 mm×20 mm×20 mm, and may include micro sensors, a processor, and wireless interface components. The Kalman filtering algorithm is preferably used to filter the noise of sensors to allow successful transformance of hand motions into recognizable and recordable English characters. The immediate advantage is the facilitation of a digital interface with both PC and mobile computing devices and perhaps to enable wireless sensing.