What is claimed is:
1. A method of guiding a tool having a working portion, to machine a work piece of a prescribed shape from a material block, comprising the steps of:
moving the working portion of the tool along a first guide path extending in an essentially planar guide surface of said block;
intersecting said first guide path at a first point on an axis of the tool during said moving step, such that said intersection is maintained at a given orientation with respect to said guide surface; and
moving a second point on said axis of said tool, which is located at a predetermined distance from said first guide path, along a prescribed second guide path.
2. The method according to claim 1, wherein said second guide path is at a constant orthogonal distance dz from the planar guide surface.
3. The method according to claim 1, wherein said first guide path includes a plurality of points, and said second guide path includes a locus of all points that are obtained by transposing each point of said first guide path to a location which includes a transportation vector that is orthogonal to said first guide path and has a first component d which is parallel to said guide surface and a second component dx which is perpendicular to said guide surface.
4. The method according to claim 1, wherein at each first point where said axis of said tool intersects said first guide path at a predetermined point in time, the respective second point where said tool axis simultaneously intersects said second guide path, is determined so as to minimize a distance between said first point and said second point at said predetermined point in time.
5. The method according to claim 1, wherein said first point is moved along said first guide path at a uniform speed, and said second guide path is represented by an approximation curve such that said second point travels along said second guide path with a minimum amount of jolts.
6. The method of guiding a tool having a working portion, to machine a work piece of a prescribed shape from a material block, comprising the steps of:
moving the working portion of the tool along a first guide path extending in an essentially planar guide surface of said block;
intersecting said first guide path at a first point on an axis of the tool during said moving step, such that said intersection is maintained at a given orientation with respect to said guide surface; and
performing an advance calculation, for each position of said first point on said first guide path and said associated orientation of said axis of said tool, to determine whether a geometrical envelope of said tool will have an interference with a surface topography of said work piece, and where an interference is found in a place other than the working portion of said tool, predicting a collision between said tool and said work piece.
7. The method according to claim 6, wherein if a collision has been predicted, said collision is avoided by the steps of:
calculating a maximum angle at which said axis of said tool can be inclined in relation to a normal vector of the guide surface, said maximum angle being an angle just below a critical angle where a collision would occur, and
reorienting said axis according to said calculated maximum angle.
8. The method according to claim 7, further comprising the step of making a recalculation subsequently; of said first guide path, taking into consideration geometric properties of the working portion of the tool.
9. The method according to claim 6, wherein said advance calculation is performed using an approximation surface that radially surrounds the tool as a substitute for the actual geometric envelope of the tool.
10. The method according to claim 1, wherein said guide paths are computed using a CAD system.
11. The method according to claim 1, wherein said first point and said second point define said given orientation of said axis at an acute angle w in relation to a normal vector of said planar guide surface.
12. The method according to claim 5, wherein said approximation curve is a cubic spline function.
13. The method according to claim 6, further comprising the step of controlling a slope angle of said axis of said tool using a CAD system to minimize any collision.
14. The method according to claim 6, wherein if a collision-free orientation of said axis can not be found, and a collision at a predicted location can not be avoided by a lateral excursion from a plane defined by said axis and a normal vector, generation of a control program to machine the work piece, is terminated.
15. The method according to claim 9, wherein said approximation surface includes a cone-shaped and a frusto-conical-shaped tool.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for controlling engine output of an internal combustion engine in a vehicle having a hydraulic power steering system, the method comprising, during an idle condition where an engine speed is set to an idle speed:
adjusting engine output based on a learned absolute steering wheel angle to vary the engine speed from the idle speed to compensate for changes in engine load caused by operation of the hydraulic power steering system, the learned absolute steering wheel angle being based on a steering wheel angle relative to a steering wheel position at vehicle startup and operating conditions from previous vehicle operation before the vehicle startup.
2. The method of claim 1, further comprising:
characterizing a suspension bind region of the absolute steering wheel angle; and
when the vehicle is stationary, adjusting engine output to increase the engine speed in response to the learned absolute steering wheel angle entering the suspension bind region.
3. The method of claim 2, wherein adjusting includes when the learned absolute steering wheel angle is in the suspension bind region, adjusting engine output to vary an increase in the engine speed as the learned absolute steering wheel angle varies relative to a steering wheel center position.
4. The method of claim 3, wherein adjusting includes, when the absolute steering wheel angle is in the suspension bind region, adjusting engine output to maintain the engine speed at an increased speed as the learned absolute steering wheel angle is held at a selected angle.
5. The method of claim 4, wherein adjusting includes adjusting engine output to decrease the engine speed to the idle speed in response to the learned absolute steering wheel angle exiting the suspension bind region toward the steering wheel center position.
6. The method of claim 1, wherein the operating conditions include a wheel speed signal from a wheel speed sensor and a wheel position signal from a wheel position sensor.
7. The method of claim 1, wherein adjusting engine output includes adjusting airflow into an intake manifold of the engine, and where engine output is further adjusted responsive to a desired engine idle speed and actual engine speed to control the actual engine speed to the desired engine idle speed.
8. The method of claim 7, wherein airflow is further adjusted based on a rate of change of the absolute steering wheel angle.
9. The method of claim 1, wherein adjusting engine output includes adjusting a range of authority of feedback spark timing of at least one spark plug of the engine.
10. The method of claim 1, further comprising:
adjusting engine output to increase the engine speed in response to the absolute steering wheel angle being greater than an end-of-travel threshold angle.