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US 5,473,542 AGranted
Method for a time-optimal, true-to-path braking of axle drives of numerically controlled machines
AssigneeSiemens Aktiengesellschaft
InventorsJurgen Olomski, Norbert Settele, Bernd Liepert
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Abstract
After an emergency braking operation is released in the case of a numerically controlled machine, the path calculated by the interpolator continues to be traveled, so that braking takes place on this path in the interpolation clock cycle. To determine the braking-interpolation points (P.sub.iB), a factor k is defined for each axle, which factor fulfills the condition of at least one axle being decelerated by a maximum amount and the remaining axles being decelerated more slowly.
Claims12
A method for a time-optimal, true-to-path braking of axle drives of numerically controlled machines, comprising steps of:
- determining interpolation points of an angular axial position A.sub.i of said axle drives over an interpolation parameter (s(t)) by an interpolator of a numerical control system of the numerically controlled machines to move the axle drives;
- calculating a braking-interpolation point when an emergency braking is released between two of said interpolation points, wherein a corresponding parameter value (s.sub.iB) of the braking-interpolation point lies between a preceding interpolation-parameter value (s.sub.i-1) and a succeeding interpolation-parameter value (s.sub.i) which would have been calculated without an emergency braking, whereby the braking-interpolation parameter value (s.sub.iB) and corresponding angular axial positions (A.sub.iB) are calculated according to the following equations:
- s.sub.iB =s.sub.i-1 +k.multidot.(s.sub.i -s.sub.i-1) (1)
- A.sub.iB =A.sub.i-1 +k.multidot.(A.sub.i -A.sub.i-1) (2);
- controlling true-to-path braking of said axle drives in response to said calculated braking-interpolation parameter value (s.sub.iB) and corresponding angular axial positions (A.sub.iB), wherein k is defined such that at least one axle drive is braked with a maximum permissible value and remaining axle drives are not braked as heavily;
- and
- implementing said calculating and controlling steps to determine each additional braking-interpolation point up until standstill of the axial movements, whereby according to the determination of equation (1) and (2) in each case, s.sub.i is replaced by s.sub.iB and A.sub.i is replaced by A.sub.iB.
4 more elements
A method for a time-optimal, true-to-path braking of axle drives of numerically controlled machines, comprising steps of:
- determining interpolation points of an angular axial position A.sub.i of said axle drives over an interpolation parameter (s(t)) by an interpolator of a numerical control system of the numerically controlled machines to move the axle drives;
- calculating a braking-interpolation point when an emergency braking is released between two of said interpolation points, wherein a corresponding parameter value (s.sub.iB) of the braking-interpolation point lies between a preceding interpolation-parameter value (s.sub.i-1) and a succeeding interpolation-parameter value (s.sub.i) which would have been calculated without an emergency braking, whereby the braking-interpolation parameter value (s.sub.iB) and corresponding angular axial positions (A.sub.iB) are calculated according to the following equations:
- s.sub.iB =s.sub.i-1 +k.multidot.(s.sub.i -s.sub.i-1) (1)
- A.sub.iB =A.sub.i-1 +k.multidot.(A.sub.i -A.sub.i-1) (2);
- controlling true-to-path braking of said axle drives in response to said calculated braking-interpolation parameter value (s.sub.iB) and corresponding angular axial positions (A.sub.iB), wherein k is defined such that at least one axle drive is braked with a maximum permissible value and remaining axle drives are not braked as heavily, wherein for each angular axial position a.sub.j an optimal factor k.sub.j results which is related to the maximum permissible braking acceleration -a.sub.max according to the following equation:
- -a.sub.max =(a.sub.j (s.sub.i-1)+k.sub.j (a.sub.j (s.sub.i)-a.sub.j (s.sub.i-1))-2a.sub.j (s.sub.i-1)+a.sub.j (s.sub.i-2))/T.sup.2.sub.ipo( 3);
- wherein T.sub.ipo is an interpolation clock time of the numerical control system;
- and
- implementing said calculating and controlling steps to determine each additional braking-interpolation point up until standstill of the axial movements, whereby according to the determination of equation (1) and (2) in each case, s.sub.i is replaced by s.sub.iB and A.sub.i is replaced by A.sub.iB.
6 more elements
Dependencies are inferred from the claim text.