Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
  • G01P15/00—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration
  • G01P15/16—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by evaluating the time-derivative of a measured speed signal
  • G01P15/165—Measuring acceleration; Measuring deceleration; Measuring shock, i.e. sudden change of acceleration by evaluating the time-derivative of a measured speed signal for measuring angular accelerations

Definitions

• the invention is based on a device according to the preamble of the main claim.
• Devices for determining the speed gradient dn / dt or degrees of an internal combustion engine are already known, for example from DE-PS 34 21 640 it is known to calculate engine speeds from the distances from speed-dependent pulse pairs and from at least two speeds calculated in this way to determine a speed change value, that is to say a speed gradient.
• the known device has the disadvantage that the calculation of the speed gradient in the control device and the calculations required for the control or regulation of the internal combustion engine run simultaneously, and as a result a high load on the computing device of the control device, in particular also during particularly time-critical phases cause.
• the device according to the invention for determining the speed gradients dn / dt with the characterizing features of the main claim has the advantage over the device known from the prior art that the computer load is reduced by the data required for the control and regulation of the internal combustion engine in one time-critical phase and the determination of the speed gradient dn / dt or ngrad takes place in a time-uncritical phase.
• FIG. 1 shows a device for speed detection and for controlling an internal combustion engine, which is already known from the external structure and is used in various motor vehicles and with which the present invention can also be implemented.
• a signal curve is plotted in FIG. 2 and a flowchart is shown in FIG. 3 which shows the determination of the speed gradient dn / dt or ngrad according to the invention.
• FIG. 1 shows a device which is suitable for carrying out the method according to the invention.
• an incremental disk 10 which has a multiplicity of identical angle marks 11, for example 60-2, on its surface, is fastened on a shaft 12, the speed or change in speed of which is to be determined.
• this shaft is the crankshaft of an internal combustion engine.
• a reference mark which in the exemplary embodiment shown is designed as a missing mark and is also referred to as a synchronous gap, is designated by 13.
• the rotational gradient for another shaft could also be determined.
• another disk with at least one angle mark could also be used.
• a segment disk with an angle mark per cylinder can be used in connection with the determination of the speed gradient of the camshaft or, correspondingly, with an angle mark per number of cylinders / 2 in the crankshaft.
• the increment disk 10 which rotates, for example, in the direction of the arrow, is scanned by a pickup 15, for example an inductive sensor, the pickup supplies speed-dependent output signals which are shaped into rectangular pulses in the pulse shaping stage 16. These are in turn evaluated in the computing device 17, for example the control unit, in order to determine quantities which are necessary for the control and / or regulation of the internal combustion engine. Time periods are formed from certain pulse intervals, and certain flank angles serve as trigger marks.
• the speed n and the speed gradient dn / dt or degree n are determined from these rectangular pulses or the times obtained therefrom.
• Segment time is denoted by t (i) in FIG. 2.
• the previous segment time would be t (i-1).
• the segment time is the time that passes in front of the transducer as a segment passes.
• segment time t (i-1) can be approximately equated with t (i) and thus both segment times can be replaced by the size K / n:
• the computing effort can be kept low by carrying out the method shown in FIG. 3.
• the time-critical computing grid only the old segment time is temporarily stored in the segment cycle and the new segment time is then calculated. There is therefore always a valid pair of values of segment times t (i) and t (i-1), from which the seg in a non-critical time grid
• FIG. 3a shows the individual steps that take place in the time-critical calculation grid in the segment cycle, where:
• step S10 the speed n is determined from a stored constant K and the read segment time t (i) by dividing the constant K by the segment time t (i).
• Step S12 calculates the third power n of the speed.
• step S13 the third power of the speed n is represented by K
• step S14 the difference between the stored segment time t (i-1) and the read segment time t (i) is formed, seg seg
• step S15 This difference is multiplied by the size n / K in step S15, so that the result of step S15 represents the desired speed gradient dn / dt.
• the program described in FIG. 3b can also run in a different order, it is essential that it only runs in non-time-critical phases and thus does not load the computing device 17 in the time-critical phases.

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• 1992
  • 1992-11-04 DE DE4237194A patent/DE4237194A1/de not_active Withdrawn
• 1993
  • 1993-10-29 US US08/256,313 patent/US5537322A/en not_active Expired - Fee Related
  • 1993-10-29 JP JP51056194A patent/JP3380244B2/ja not_active Expired - Fee Related
  • 1993-10-29 DE DE59308547T patent/DE59308547D1/de not_active Expired - Fee Related
  • 1993-10-29 EP EP93923454A patent/EP0619886B1/de not_active Expired - Lifetime
  • 1993-10-29 WO PCT/DE1993/001038 patent/WO1994010577A1/de active IP Right Grant

Patent Citations (2)

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