US 7,505,865 B2 · Velocity detection, position detection and navigation system

Abstract

As an embodiment of the present invention, in a navigation system using an acceleration sensor, when position information cannot be obtained from a GPS processing section, a velocity detecting unit performs an operation using detected acceleration αG, a measurement time mt, a velocity V0 at a time t0, gravity acceleration g and an amount of height change Dh, according to Expression (11). By using the relationship among a gravity acceleration component gf, the gravity acceleration g, the amount of height change Dh and distance Dm shown in Expression (4), the gravity acceleration component gf can be offset by the amount of height change Dh. Therefore, velocity V can be calculated with high accuracy without receiving the effect of the gravity acceleration component gf.

Claims36

Dependent claims

A velocity detecting system comprising:

an acceleration sensor for obtaining detected acceleration corresponding to a result of that mobile body acceleration in a forward direction in a predetermined mobile body was added to a component of said forward direction being gravity acceleration operating on the mobile body;
amount of height change calculating means for calculating an amount of height change of said mobile body in a predetermined measurement time, based on a surrounding pressure of said mobile body detected by a predetermined pressure sensor;
and
velocity calculating means for obtaining said mobile body acceleration by offsetting said forward direction component included in said detected acceleration based on the amount of height change, by utilizing a ratio of said forward direction component of said gravity acceleration to the gravity acceleration corresponds to a ratio of said amount of height change to a moving distance of said mobile body in said measurement time, and calculating a velocity of said mobile body at a measurement finish point by using the mobile body acceleration, based on a known velocity of said mobile body at a measurement start point.

1 more element

A position detecting system comprising:

an acceleration sensor for obtaining detected acceleration including mobile body acceleration in a forward direction in a predetermined mobile body and a component of said forward direction being gravity acceleration operating on the above mobile body;
an angular velocity sensor for detecting an angular velocity in the shaft revolution vertical to a horizontal direction in said mobile body;
amount of height change calculating means for calculating an amount of height change of said mobile body in a predetermined measurement time, based on a surrounding pressure of said mobile body detected by a predetermined pressure sensor;
velocity calculating means for offsetting said forward direction component included in said detected acceleration by the above amount of height change, by utilizing that a ratio of said forward direction component of said gravity acceleration to the above gravity acceleration is equal to a ratio of said amount of height change to a moving distance of said mobile body in said measurement time, and calculating a velocity of said mobile body at a finish point of said measurement time, based on velocity of said mobile body at a start point of said measurement time;
and
position information calculating means for calculating a position information of said mobile body at the finish point of said measurement time, based on the position information of said mobile body at the start point of said measurement time, and said calculated velocity and angular velocity of said mobile body.

3 more elements

A velocity detecting system comprising:

an acceleration sensor for obtaining detected acceleration corresponding to a result of mobile body acceleration in a forward direction in a predetermined mobile body was added to a component of said forward direction being gravity acceleration operating on the mobile body;
a mechanism calculating an amount of height change of said mobile body in a predetermined measurement time, based on a surrounding pressure of said mobile body detected by a predetermined pressure sensor;
and
a mechanism obtaining said mobile body acceleration by offsetting said forward direction component included in said detected acceleration based on the above amount of height change, by utilizing that a ratio of said forward direction component of said gravity acceleration to the above gravity acceleration corresponds to a ratio of said amount of height change to a moving distance of said mobile body in said measurement time, and calculating a velocity of said mobile body at a measurement finish point by using the above mobile body acceleration, based on a known velocity of said mobile body at a measurement start point.

1 more element

Dependencies are inferred from the claim text.

Velocity detection, position detection and navigation system

Life of this patent

Velocity detection, position detection and navigation system

Life of this patent

Abstract

Claims36