Uninterrupted navigation with Dead Reckoning GPS

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Situations where GPS signals are blocked are unavoidable, particularly in tunnels and underground parking garages. In these environments, u-blox’ Dead Reckoning (DR) technology allows uninterrupted vehicle navigation based on heading and distance data provided by external sensors. From the last known position, a vehicles’ current position can be calculated using information gathered from one of two methods: External Sensors: Dead Reckoning using Gyroscope and Tachometer Individual Wheel Speed: Dead Reckoning using Individual Wheel Speed Information These sensors can be directly connected to the GPS receiver or the sensor readings can be obtained through the vehicle data bus. When GPS satellites are out of sight, GPS location is extrapolated using distance and angle information from the sensors. This results in accurate positioning even when the GPS signal is impaired or absent. DR not only allows full coverage in indoor car parks, tunnels and underpasses but also effectively eliminates the impact of multipath effects in urban canyon environments. External sensor solution: using gyroscope and odometer pulses from a tachometer together with the u-blox LEA-4R or TIM-4R GPS receiver modules make this solution independent of the vehicle data bus and ideal for after-market applications Individual wheel speed solution: ideal for first-mount navigation systems because it uses information from the vehicle data bus. This solution requires a close collaboration between the car manufacturer and the automotive component suppliers to ensure the system identifies and accesses sensor data Read the u-blox DR article published in GPS World: “Continuous Navigation: Combining GPS with Sensor-Based Dead Reckoning." u-blox compatible with Dead Reckoning: DR based on individual wheel speed: LEA-4R and TIM-4R GPS receiver modules DR based on wheel speed: u-blox 5 Automotive GPS chips