Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
A vehicular navigation apparatus comprising: a distance sensor; a steering angle sensor; a curve detecting unit provided with inputs of a distance signal and steering-angle s-ignal for calculating a change in vehicle travelling direction by referring to a steering angle - travelling direction conversion table; a course exploration unit provided with inputs of present position and destination for performing course exploration based on intersection data, road data and node data; a comparison-decision unit for comparing retrieved course data and results of curve detection; and a guidance processor for executing predetermined guidance processing based on the results of comparison.
Claim 2
Dependent Claim
98 words
A vehicular navigation apparatus comprising: a distance sensor; a steering angle sensor; a curve detecting unit provided with inputs of a distance signal and steering-angle s-ignal for calculating a change in vehicle travelling direction by referring to a steering angle - travelling direction conversion table; a course exploration unit provided with inputs of present position and destination for performing course exploration based on intersection data, road data and node data; a comparison-decision unit for comparing retrieved course data and results of curve detection; and a guidance processor for executing predetermined guidance processing based on the results of comparison.
Claim 3
Dependent Claim
56 words
A vehicular navigation apparatus according to claim 1, wherein the guidance processor calculates present position by performing a distance correction based on intersection position data or node position data when the difference between an angle of an intersection or node of a retrieved course and the results of curve detection is less than a predetermined value.
Claim 4
Dependent Claim
33 words
A vehicular navigation apparatus according to claim 2, wherein distance computation is performed with the intersection position being taken a geographical point at which steering angle is maximum during detection of a curve.
Claim 5
Dependent Claim
45 words
A vehicular navigation apparatus according to claim 1, wherein the guidance processor provides an off-course indication and instructions for subsequent countermeasures when it is determined that the vehicle is not on a predetermined course by comparing retrieved course data and the results of curve detection.
Claim 6
Dependent Claim
34 words
A vehicular navigation apparatus according to claim 4, wherein the off-course indication and the instructions for subsequent countermeasures provided by the guidance processor are given in the form of a display or voice output.
Claim 7
Dependent Claim
84 words
A vehicular navigation apparatus according to claim 4, wherein, when the vehicle is detected to be off course, the vehicle is stopped and a new course from a geographical point at which the vehicle is stopped to a destination is found, the guidance processor compares the new course and an original course and, based on the results of the comparison, gives instructions to travel in accordance with the new course or to return to a geographical point at which the vehicle went off course.
Claim 8
Dependent Claim
60 words
A vehicular navigation apparatus according to claim 4, wherein, when the vehicle is detected to be off course, the vehicle is stopped and a new course from a geographical point at which the vehicle is stopped to a destination cannot be found, the guidance processor gives instructions to return to a geographical point at which the vehicle went off course.