1. A mobile apparatus that has a control system, and adjusts independently a position and a posture thereof according to a first action plan element defining a position-variation mode and a second action plan element defining a posture-variation mode, respectively, with a movement thereof controlled by the control system, wherein said control system comprises: a first processing section which recognizes a current image of said mobile apparatus, a current image of an object, and an intermittent or continuous future image of the object, which is determined according to the behavior of the object and has a larger size than the current image thereof, as a reference spatial element, a first spatial element and a second spatial element having a larger size than the first spatial element, respectively, on a discriminant plane including at least a part of an end point trajectory of said mobile apparatus determined based on said second action plan element; a second processing section which determines, based on the result of the recognition by the first processing section, whether or not there is the first spatial element that satisfies a contact condition which refers to a second contact condition that there exists an intersection point or contact point between the reference spatial element and the first spatial element on the discriminant plane when the reference spatial element moves along a route which serves as the first action plan element, or a first contact condition that a movement cost defined in a way that the movement cost becomes higher when a distance from the reference spatial element to the first spatial element is longer is within a prescribed range and the second contact condition; and a third processing section which assumes the second action plan element involving changing the end point trajectory and makes the first processing section recognize the reference spatial element, the first spatial element and the second spatial element on a new discriminant plane including at least a part of the changed end point trajectory and determine whether or not the first spatial element that satisfies the contact condition on the new discriminant plane under the assumption exists, when the second processing section determines that there is a first spatial element that satisfies the contact condition on the discriminant plane, and modifies the route which serves as the first action plan element so as to avoid the reference spatial element from contacting the second spatial element on the discriminant plane including at least a part of the end point trajectory not changed based on the result of the recognition by the first processing section when the second processing section determines that there is still a first spatial element that satisfies the contact condition on the new discriminant plane, and sets the assumed second action plan element as a new second action plan element when the second processing section determines that there is no first spatial element that satisfies the contact condition on the new discriminant plane.