Navigation device and method for position determination by means of dead reckoning
First Claim
Patent Images
1. Navigation device for dead reckoning, comprising:
- an input for receiving a distance signal from a sensor for determining a distance;
an input for receiving a direction signal from a sensor for determining a direction;
a processor for position calculation based on the distance signal and the direction signal received from the sensors;
a memory device connected to said processor and having stored therein a digitized road map for comparison with a calculated position;
a memory connected to said processor for storing a sequence of deviations between each of a series of calculated positions and a corresponding position on the digitized road map;
said processor being programmed to correct a calculated position using a correction value derived on a basis of the stored sequence of deviations; and
to save a sequence of deviations for deriving a correction value in the memory until a new deviation to be saved lies outside a defined limit.
2 Assignments
0 Petitions
Accused Products
Abstract
The navigation device and the corresponding method for position determination utilize dead reckoning. A position is calculated by a processor on the basis of measured values from a distance sensor and a direction sensor. The measured values are compared with a probable position on a stored digital road map. The deviation between the calculated position and the corresponding position on the digitized road map can be saved. Saved deviations form the basis of a correction value with which the calculated position can be corrected.
157 Citations
11 Claims
-
1. Navigation device for dead reckoning, comprising:
-
an input for receiving a distance signal from a sensor for determining a distance;
an input for receiving a direction signal from a sensor for determining a direction;
a processor for position calculation based on the distance signal and the direction signal received from the sensors;
a memory device connected to said processor and having stored therein a digitized road map for comparison with a calculated position;
a memory connected to said processor for storing a sequence of deviations between each of a series of calculated positions and a corresponding position on the digitized road map;
said processor being programmed to correct a calculated position using a correction value derived on a basis of the stored sequence of deviations; and
to save a sequence of deviations for deriving a correction value in the memory until a new deviation to be saved lies outside a defined limit. - View Dependent Claims (2, 3)
-
-
4. A method of determining a position by dead reckoning, which comprises the following steps:
-
acquiring measured values for a distance traveled and a direction;
forming vectors from the measured values for the distance traveled and for the direction and summing the vectors with a processor;
determining a difference between a calculated position and a corresponding probable position on a digitized road map and saving the difference as a deviation from the probable position;
calculating a correction value based on chronologically sequential deviations;
adding each correction value to a subsequently calculated position; and
saving a sequence of deviations for deriving the correction value in the memory until a new deviation to be saved lies outside a defined limit. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11)
-
Specification