Abstract: An method and apparatus for estimating a time delay of a GPS receiver in a hybrid navigation system is disclosed. In the hybrid navigation system including the GPS receiver and a DR system, a time difference between a time, at which a velocity measured by the DR system exceeds a reference velocity, and a time, at which a velocity measured by the GPS receiver exceeds the reference velocity, is measured to calculate the time delay of the GPS receiver, so that a GPS/DR system having a loosely-coupled structure which considers the time delay can be realized. Further, in the system, when a vehicle moves from a GPS reception area to a non-reception area and a GPS/DR system mode changes into a DR system mode, an initial velocity value can be estimated while a time delay is considered for a DR system.

Abstract: Disclosed is a stride-based route guiding apparatus and method capable of providing a pedestrian with a stride-based route. The method includes detecting a stride of the pedestrian on the basis of a pace inherent to the pedestrian of interest and converting a remaining distance from a current position to a major position or destination into the number of steps so as to provide the pedestrian with the number of steps to the major position or destination when a route is shown, using a navigation system built in a mobile terminal. Since the route is shown on the basis of the number of steps inherent to the pedestrian, the pedestrian can receive the routing more familiar to herself or himself, and easily and intuitively perceive the route from the current position to the major position or destination.

Abstract: A positioning system using a mobile Internet signal is disclosed. The positioning system includes access points for transmitting downlink signals for mobile Internet communications, an access terminal for generating positioning information using the downlink signals received from the access points and access point information on the access points, and a position determination entity (PDE) for calculating range values between the access terminal and the access points using the positioning information from the access terminal and determining a position of the access terminal using the range values. Since the positioning system determines the position using the mobile Internet signal, an accurate terminal position can be determined even in such environments as downtown, shaded and indoor areas.

Abstract: Disclosed is an apparatus and a method for measuring the speed of a land vehicle using an accelerometer. The method includes the steps of storing measurement data provided from an accelerometer; analyzing the measurement data to determine whether the vehicle is stopped; calculating a road angle using the measurement data of the accelerometer when it is determined, upon analysis, that the vehicle is moving; determining the sign of the road angle when the road angle is greater than a threshold value; compensating for a gravitational acceleration component included in the measurement data of the accelerometer using the road angle; and calculating the speed of the vehicle based on the acceleration of the vehicle with the gravitational acceleration component compensated. It is possible to reduce the number of expensive gyroscopes needed for a vehicle speed measuring apparatus, thereby reducing the cost of the apparatus.

Abstract: Disclosed are an apparatus and a method for measuring the speed of a moving body using an accelerometer. A value of earth's gravitational acceleration component is detected from the measurements from the accelerometer and is removed from the acceleration value. Then, the acceleration value, after removal of the earth's gravitational acceleration component, is used to obtain the speed of the moving body. The earth's gravitational acceleration component is detected using a movement average at a point of time when the speed of the moving body is to be measured. By using the magnitude of a difference between a value obtained by removing an x-axis movement average from an x-axis measurement from the two-axis accelerometer and another value obtained by removing a y-axis movement average from a y-axis measurement from the two-axis accelerometer, it is possible to regulate a window for calculating the movement average and a weight value to each of the measurements included in the window.

Abstract: Disclosed is an apparatus and a method for measuring the speed of a land vehicle using an accelerometer. The method includes the steps of storing measurement data provided from an accelerometer; analyzing the measurement data to determine whether the vehicle is stopped; calculating a road angle using the measurement data of the accelerometer when it is determined, upon analysis, that the vehicle is moving; determining the sign of the road angle when the road angle is greater than a threshold value; compensating for a gravitational acceleration component included in the measurement data of the accelerometer using the road angle; and calculating the speed of the vehicle based on the acceleration of the vehicle with the gravitational acceleration component compensated. It is possible to reduce the number of expensive gyroscopes needed for a vehicle speed measuring apparatus, thereby reducing the cost of the apparatus.

Abstract: An method and apparatus for estimating a time delay of a GPS receiver in a hybrid navigation system is disclosed. In the hybrid navigation system including the GPS receiver and a DR system, a time difference between a time, at which a velocity measured by the DR system becomes equal to a reference velocity, and a time, at which a velocity measured by the GPS receiver becomes equal to the reference velocity, is measured to calculate the time delay of the GPS receiver, so that a GPS/DR system having a loosely-coupled structure which considers the time delay can be realized. Further, in the system, when a vehicle moves from a GPS reception area to a non-reception area and a GPS/DR system mode changes into a DR system mode, an initial velocity value can be estimated while a time delay is considered for a DR system.

Abstract: A method and apparatus for measuring the velocity of a vehicle are provided. An acceleration measurement received from an accelerator and RGI data received from an external information server are stored and an irregularity constant of the accelerator is determined. It is determined whether the vehicle is in a stationary state by analyzing the acceleration measurement. If the vehicle is not in the stationary state, the inclination angle of a road on which the vehicle is traveling is calculated using a plurality of three-dimensional shape points included in the RGI data. A gravity acceleration component is compensated for from the acceleration measurement using the road inclination angle. The velocity of the vehicle is calculated using the compensated acceleration measurement.

Abstract: Disclosed are an apparatus and a method for measuring the speed of a moving body using an accelerometer. A value of earth's gravitational acceleration component is detected from the measurements from the accelerometer and is removed from the acceleration value. Then, the acceleration value, after removal of the earth's gravitational acceleration component, is used to obtain the speed of the moving body. The earth's gravitational acceleration component is detected using a movement average at a point of time when the speed of the moving body is to be measured. By using the magnitude of a difference between a value obtained by removing an x-axis movement average from an x-axis measurement from the two-axis accelerometer and another value obtained by removing a y-axis movement average from a y-axis measurement from the two-axis accelerometer, it is possible to regulate a window for calculating the movement average and a weight value to each of the measurements included in the window.

Abstract: An apparatus and method for sensing a state of a movable body. According to the apparatus and method, since image information regarding a dashboard of a movable body is collected and a state of the movable body is sensed by analyzing the collected image information by means of image recognition technologies, the state of the movable body can be accurately sensed without an odometer and without a separate wire connection in the movable body. Further, when the apparatus and method are applied to a navigation system, more accurate position information and path guidance can be provided to users of the navigation system.