672 results about "Dead reckoning" patented technology

A navigation system uses a dead reckoning method to estimate an object's present position relative to one or more prior positions. In some embodiments, the dead reckoning method determines a change in position from the object's heading and speed during an elapsed time interval. In embodiments suitable for use with wheeled objects, the dead reckoning method determines the change in position by measuring the heading and the amount of wheel rotation. Some or all of the components of the navigation system may be disposed within a wheel, such as a wheel of a shopping cart.

Methods and apparatuses for estimating a user's altitude with respect to the mean sea level are provided. According to some aspects, the present invention is able to estimate altitude in both open sky as well as in degraded GPS signal environments such as dense urban canyon environments where GPS performance is affected by fewer available satellites and/or multipath error. According to other aspects, the present invention uses data from a pressure sensor to estimate altitude, either with or without the use of GPS aiding data. According to further aspects, estimated altitude is integrated with other types of dead reckoning data to provide user context detection pertaining to changes of altitude.

An object of the present invention is to provide a charging system which carries out position confirmation of a moving body at a place where there is a radio wave blocked facility, and which carries out automatic detection of GPS antenna blockage for avoiding charging. In a charging system including a GPS positioning device 921 for recognizing a vehicle position, a vehicle speed pulse measuring device 920 for dead reckoning navigating, a monitor device 920, 927, 928 which generates information expressing a current position by using these, and a charging processing 902 which judges whether or not a recognized current position is within a charge area and which carries out data processing for charging, the monitor 920 includes a simple map database 928 which includes positions of facilities or geographical features at which GPS positioning is impossible, and when GPS positioning is impossible, the facility or geographical feature corresponding to the current position is detected, and that position is made to be a current position.

The invention discloses a machine vision and inertial navigation fusion-based mobile robot motion attitude estimation method which comprises the following steps of: synchronously acquiring a mobile robot binocular camera image and triaxial inertial navigation data; distilling front/back frame image characteristics and matching estimation motion attitude; computing a pitch angle and a roll angle by inertial navigation; building a kalman filter model to estimate to fuse vision and inertial navigation attitude; adaptively adjusting a filter parameter according to estimation variance; and carrying out accumulated dead reckoning of attitude correction. According to the method, a real-time expanding kalman filter attitude estimation model is provided, the combination of inertial navigation and gravity acceleration direction is taken as supplement, three-direction attitude estimation of a visual speedometer is decoupled, and the accumulated error of the attitude estimation is corrected; and the filter parameter is adjusted by fuzzy logic according to motion state, the self-adaptive filtering estimation is realized, the influence of acceleration noise is reduced, and the positioning precision and robustness of the visual speedometer is effectively improved.

The invention discloses a transformer station inspection tour robot positioning navigation system and a method. Confidence obtained by a laser range finding module and a dead reckoning module is outputted to a map creation module and a pose resolving module; the map creation module creates a laser road sign map and a laser grid map which show a robot operation environment and are inputted into a map storage module for storage; the posture resolving module utilizes map data in the map storage module and output data of the dead reckoning module to perform real-time calculation on the current position and the posture of the robot and accesses the obtained posture data into a path planning module and a motion control module; the path planning module generates robot operation path data which is outputted to the motion control module; the motion control module generates motion control quantity according to the current position and posture data of the robot and the path planning data, and then is driven to execute by a motor. The transformer station inspection tour robot positioning navigation system realizes the accuracy positioning of the inspection tour robot in the transformer station.

An apparatus and method for estimating a position of a mobile device based on one or more images is disclosed. Positioning information is derived from an image containing an SAS (self-addressing source such as a QR code), thereby setting a first vector V₁ and an SAS pose. The image is also used to determine a displacement between the mobile device and the self-addressing source, thereby setting a second vector V₂. Using the first vector V₁, the SAS pose and the second vector V₂, the mobile device may estimate its position with high accuracy and may also recalibrate dead-reckoning navigation and a gyrometer.

Described herein is a GPS pet containment system is that generally self contained within a collar. However, the collar includes a battery power source, a microcontroller powered by the battery power source, a global positioning system (GPS) interfaced to the microcontroller and an accelerometer interfaced to the microcontroller. The GPS operates to provide collar location information on a periodic basis while the accelerometer provides collar dead reckoning location information on a substantially continuous basis. The dead reckoning location information is acquired by integrating the acceleration value provided by the accelerometer over sub-second time intervals.

A map matching method and apparatus for a navigation system estimates a location of the navigation system on a correct road segment when a GPS signal is invalid. The map matching method creates a database of pairs of locations at which the navigation system encountered GPS signal loss and recovery in the first time. The navigation system conducts a map matching processing when the GPS signal is lost in the second time at the recorded location by incorporating various additional factors to match the current position with a correct road segment. The various additional factors, in addition to the measured data by a dead reckoning process, include road class, road accessibility, road angle, proximity to candidate road, etc.

The invention is related to methods and apparatus that use a visual sensor and dead reckoning sensors to process Simultaneous Localization and Mapping (SLAM). These techniques can be used in robot navigation. Advantageously, such visual techniques can be used to autonomously generate and update a map. Unlike with laser rangefinders, the visual techniques are economically practical in a wide range of applications and can be used in relatively dynamic environments such as environments in which people move. One embodiment further advantageously uses multiple particles to maintain multiple hypotheses with respect to localization and mapping. Further advantageously, one embodiment maintains the particles in a relatively computationally-efficient manner, thereby permitting the SLAM processes to be performed in software using relatively inexpensive microprocessor-based computer systems.

Road map feedback is used in a tightly coupled GPS and dead-reckoning system that collects wheel speed transducer data over a vehicle's CANbus network to compute vehicle range and direction. Road segment information provided by a network server provides a database of constraints that are templated on to current navigation solutions so that corrective feedback can be derived. The dead-reckoning bridges over gaps in navigation solutions that would otherwise occur when GPS signal transmission is lost in tunnels, parking garages, and other common situations. The road map fitting controls drift that would otherwise accumulate during long periods of dead reckoning only operation.

A navigation device includes a computer platform that includes a global positioning system (GPS) receiver operable to acquire and track a GPS signal, a processor assembly, and a memory. The memory includes at least one of last recorded Ephemeris and Almanac information, and a GPS velocity vector determination module operable to generate a velocity vector output in the absence of current Ephemeris based upon the tracked GPS signal and the last recorded GPS information. A method of vehicle navigation in the absence of current Ephemeris includes acquiring and tracking a GPS signal, retrieving from a memory a last recorded location of a vehicle, setting a dead reckoning startup location equal to the last recorded location, retrieving from a memory at least one of a last recorded Ephemeris and Almanac, determining a current velocity vector and determining a current location based upon the velocity vector and the dead reckoning startup location.

The invention provides a pedestrian inertial positioning system based on indoor magnetic field feature assistance. The system comprises a magnetic field and inertial data obtaining module, a magnetic field positioning module, a pedestrian dead reckoning module, a positioning fusion module and an output module, wherein the magnetic field and inertial data obtaining module is used for acquiring magnetic field, accelerated speed and angular velocity information; the magnetic field positioning module is used for building a magnetic field feature library and carrying out time-frequency analysis on the magnetic field vector sequence in real time to extract the time-frequency feature, and matching with the magnetic field feature library to carry out magnetic field feature positioning; the pedestrian dead reckoning module is used for updating accelerated speed and angular velocity zero offset according to the condition that the step velocity discontinuity is zero during walking, judging the step number and calculating the step length and the direction of each step; the positioning fusion module is used for fusing a magnetic field feature positioning result and a pedestrian dead reckoning inertial positioning result by means of particle filter; and the output module is used for displaying a positioning result on web pages and terminals. The system provided by the invention has the characteristics of being independent from beacon during positioning, low in cost and consumption of positioning terminals, accurate in positioning result and adaptive to environment change.

Mobile localization of an object having an object positional frame of reference using sparse time-of-flight data and dead reckoning can be accomplished by creating a dead reckoning local frame of reference, including an estimation of object position with respect to known locations from one or more Ultra Wide Band transceivers. As the object moves along its path, a determination is made using the dead-reckoning local frame of reference. When the object is within a predetermine range of one or more of the Ultra Wide Band transceivers, a “conversation” is initiated, and range data between the object and the UWB transceiver(s) is collected. Using multiple conversations to establish accurate range and bearing information, the system updates the object's position based on the collected data.

A packet is routed by "dead reckoning" on a network having a generally regular topology. The packet is received at a node where a local routing decision is made. The packet is output in a direction selected according to the routing decision. The packet carries in addition to a destination address a directional flag indicating explicitly the preferred direction of onward travel and the routing decision is made using this flag. Several flags may be used, corresponding to different dimensions of the network.

The invention discloses an integrated navigation device for an underwater glider and a navigation method therefor. The integrated navigation device for an underwater glider is characterized in that the integrated navigation device comprises an electronic compass, a micro-electro-mechanical system (MEMS) inertia measurement unit, a global satellite system receiving module and a digital signal processing module; an inertial integrated navigation and positioning system comprising the electronic compass and a posture measuring unit comprising a MEMS gyro and an accelerometer cooperates with a control system; a digital signal processor (DSP) module is utilized as a navigation resolving part; and independent and accurate positioning of an underwater glider is realized through processes of noise reduction, temperature compensation, non-linear correction, cross-coupling compensation and dead reckoning on various sensors in a full temperature range. The integrated navigation device for an underwater glider has a small volume, a high integration level, low power dissipation, long endurance and a low cost, can fast and accurately acquire current posture and position information of an underwater glider, can keep the balance of the underwater glider, and can provide track and position parameters for the underwater glider.

The invention discloses an indoor movable robot real-time navigation method based on visual information correction, comprising the following steps of: (1) initializing a robot navigation system, and starting a mile meter and a visual sensor; (2) obtaining the current position of a robot by the mile meter and the visual sensor and forming a kalman filter so as to obtain a mile meter filtration estimation value and a visual sensor filtration estimation value; (3) fusing the mile meter filtration estimation value and the visual sensor filtration estimation value; and (4) resetting parameters. The invention sufficiently utilizes the respective advantages of visual information and mile meter information and combines the precision of the visual information and the real-time property of the mile meter information; the invention utilizes the mile meter self information to carry out the recurrence computation to obtain navigation data at most of the time, thereby ensuring the real-time requirement of the navigation system; in addition, the invention also utilizes the visual information to correct the accumulated errors generated in the dead reckoning of the mile meter, thereby greatly enhancing the accuracy of the navigation system.

A vehicle hitch assistance system includes an imaging system, a steering system, a dead reckoning system, and a controller. The controller determines a hitch location within a vehicle exterior image received from the camera system, derives a vehicle path to align a hitch ball of the vehicle with the hitch location, and controls the steering system to guide the vehicle along the path including tracking the location of the vehicle using information received from the dead reckoning system.

A method of estimating a position of a mobile object in a navigation system is provided that comprises the steps of: loading a mobile object position data backed up during stoppage of the mobile object, at an initial stage of travel as the mobile object restarts traveling; estimating a current position of the mobile object from the loaded position data of the mobile object by dead reckoning navigation; causing the estimated current position of the mobile object to be matched to a map data; determining whether the mobile object has entered a link, based on the mobile object position matched to the map data and detection signals indicative of the travel conditions of the mobile object generated from a sensor part; and estimating the current position of the mobile object by establishing the azimuth angle of the link as an azimuth angle of the mobile object through the dead reckoning navigation if the mobile object is determined to have entered the link.

An apparatus and method to enhance dead-reckoning navigation using inertial sensor measurements based on images from a camera are disclosed. A camera build into a mobile device is used to calibrate inertial sensors and rotation matrices. Images from a camera may be used (1) to remove a gravitational element from accelerometer measurements; (2) to set a scaling factor and an offset for a gyrometer; and (3) to set initial and updated values for rotation matrices.