DE3307833A1 - Device for indicating and/or storing errors of transmitter arrangements on internal combustion engines - Google Patents

Abstract

In this device, a reference mark generator (13) coupled to the crankshaft generates at least one reference mark per revolution and a further signal transmitter, particularly a phase signal transmitter (14) coupled to the cam shaft is provided for generating further transmitter signals which have a fixed correlation with the signals of the reference mark transmitter. In the event of a deviation from the prescribed order and prescribed distances of references marks (r) and further transmitter signals (p), an error signal is generated which is stored and/or supplied to a display device (15). In this manner, it is possible to detect not only missing pulse sequences and thus faults in the transmitter arrangements or feedlines but also intermittent contacts and angle displacements of the transmitter signals with respect to one another. <IMAGE>

Description

R. J Ö

1 .3.1933 Ve / Kc

ROBERT BOSCH GMBH, TOOO STUTTGART 1

Device for displaying and / or storing errors in encoder orders from internal combustion engines

State of the art

The invention is based on a device according to the preamble of the main claim. Especially with five-cylinder internal combustion engines is for electronic ignition systems for cylinder detection except one from the crankshaft removed reference mark signal, a phase signal is necessary. The phase signal generator is with coupled to the camshaft and usually as an inductive, optical or Hall sensor in the distributor educated. In addition to these encoder arrangements, there is often a speed encoder whose signals pass through a gear coupled to the crankshaft can be generated. Such complicated encoder systems can for example also for complex fuel injection systems or other control systems are used.

If a fault occurs in the system, it is often difficult to determine which fault is based on which encoder arrangement this is due. By recognizing the right one Error can then be an unnecessary encoder exchange, an unnecessary cable repair or an unnecessary exchange of the control unit in the workshop. For example, if a fiducial signal during a Phase signal would have to appear with proper function, but it appears only afterwards, so this can be different Causes: loose contact of the phase signal or loose contact of the reference mark signal or twisting the distributor.

From DE-OS 32 O ^ 003 is a system for the detection, Storage and display of various errors from encoders and switching devices in motor vehicles known. there however, only errors of individual components are indicated by limit value queries, but not the causes of the error, especially when several components interact (e.g. encoder arrangements, especially pulse encoders ) j

Advantages of the invention

D. the device according to the invention with the characteristic Features of the main claim has the advantage that when an error is detected this not only but first investigate its possible causes. Only when the cause is identified the error can then be identified in more detail in a clear manner, i.e. in particular when it comes to interaction several components, that component (encoder arrangement) can be designated which is the cause of is responsible for the mistake. So besides total

-ζ-

Defects, such as short circuits or interruptions, also loose contacts and angle errors in the encoder arrangements are recognized to each other. Reading out or reading off the stored errors in the workshop is made easier this eliminates the error and avoids the unnecessary replacement of components.

The measures listed in the subclaims are advantageous developments and improvements the device specified in the main claim possible.

drawing

An embodiment of the invention is shown in the drawing and explained in more detail in the following description. 1 shows a schematic representation of a control device for an internal combustion engine, which is connected to various "rotary encoder assemblies, Figure 2 shows a signal chart for explaining proper signal sequences of the donor arrangements, Figure 3 is a flowchart for explaining the error checking and Figure H is a flowchart for more detailed illustration error checking of speed signals.

Description of the embodiment

In the exemplary embodiment shown in FIG. 1, there is a control device 10 designed as a microcomputer shown, which controls ignition and injection output stages 11 on the output side. On the input side are this control unit 10 speed signals η of a speed sensor 12, reference mark signals r one with the crankshaft and thus with the speed encoder 12 coupled reference mark encoder 13 as well as phase signals ρ of one with the cam

Wave of the internal combustion engine connected phase encoder I ** supplied. These sensors can be inductive, optical or Hall sensors. The control device 10 not only contains the control functions for the ignition and / or the fuel injection of the internal combustion engine, but also contains a diagnostic system for the transmitter arrangements . 12 to 1 h. The result of the diagnosis is in each case stored in one of the memories of the microcomputer and can be identified immediately or later in the workshop via the display device 15. The display device 15 can consist of control lamps for the various types of errors, a display for direct identification of the errors, a measuring instrument or some other device for differentiating between the various errors. Methods for error storage and error display are described in more detail in the prior art mentioned at the beginning and are therefore not listed again in detail.

The signal diagram shown in FIG. 2 shows the different encoder signals in their position to each other. The generated in particular designed as a tooth transmitter Speed sensor 12 a large number of speed signals per revolution of the crankshaft, e.g. 135. The reference mark sensor 13 generates a reference mark signal r per revolution of the crankshaft, so that the distance between two reference mark signals corresponds to a number Z of speed signals η. The one coupled to the camshaft Phase signal generator also generates a phase signal P per revolution of the camshaft, so that this Phase signal P occurs once every second revolution of the crankshaft and then - with proper function with must coincide with a reference mark signal r.

wÖ /

The phase signal has a signal width of Zp speed signals. This usually in the distributor arranged phase signal generator is required for cylinder detection in five-cylinder engines.

By logically combining the three signals n, r and ρ with one another, it is possible, in addition to the absence of these pulses or pulse sequences also the correct position of the signals r and ρ to one another and thus the correct one Recognize and display the setting of the distributor. In addition, there may be a loose contact on the encoder cables in addition to the static error of the respective pulse train detected and displayed accordingly will. This test by means of logical linking can be carried out in an existing microcomputer of a control unit which contains a self-diagnosis query according to the stated state of the art in the program sequence. The test process can precede the actual control process (ignition, injection), the test process or the test program and the main program can be nested in one another, or the test program can be called cyclically during the main program.

The test sequence is explained in the flow chart shown in FIG. 3, whereby it is the most important criterion is that certain errors in the timing of the signal sequences can have several causes and therefore an error is only saved and displayed if it clearly relates to a specific signal or a can be assigned to a specific cause. After the start (20) of the test sequence in the microcomputer 10 takes place first in the usual way an initialization (21)

that is, all errors are cleared and all registers, flip-flops and counters are reset. A speed error (22) is then set in advance. This speed error is referred to as n-error 1, which is deleted again (2U) after the appearance of an n-edge (23). A special possibility of error for the η-signal is checked not in a particular test sequence (.68), the k in Figure is described in more detail.

After the n-error 1 has been deleted (2 ^), an "η counter" in the microcomputer 10 is set to the value Kuli (25) to check the phase signal. This counter - four more are required - can also be registers of the microcomputer, but the addition can also take place in the accumulator, with the results being stored in memory cells. The η counter is now increased by the value 1 (26). A phase signal edge is then awaited (27). If there is no p-edge, it is queried whether the η counter contains a value that is greater than Uz + K (28). Here, kZ corresponds to four crankshaft revolutions, ie two phase signals would have to occur in this interval, the absence of a p-signal being initially tolerated for the test. If there is no such tolerance, the value 2Z would have to be requested instead of kZ. K is a tolerance factor. If condition (28) is not met, the η counter is increased again by the value 1 (26). As long as no p-edge occurs, this process continues until the value UZ + K is reached, whereby a phase error signal (p-error 1) 'is saved (29) and, if necessary, displayed. This error signal shows that either the phase signal generator 1 U is defective or that there is a line interruption or a line short circuit. It is then not possible to control the ignition and / or injection.

, * λ - a "" * rfC "" ^ j ^ s j χ. Ρ

If, on the other hand, a p-edge occurs (27), the system waits, until the phase signal assumes the value 0 (30), i.e. until the beginning of a phase signal is reached (the phase signal is a 0 signal). Now it is checked whether a reference mark signal r is present. To do this, the η counter is set to the value 0 (31), and then increased by the value 1 (32). The appearance of a reference mark signal r is now queried (33). If there is no reference mark signal r, this query takes place with constant increment of the n-counter (32) as long as how the phase signal (3 ^, p = 0) is present. First it is assumed that a reference mark signal r appears properly during this phase signal (33).

It is now checked whether there is a loose contact (p-error 2) of the phase signal. To this end, a check is made as to whether a 1 signal is present in the proper manner by the phase signal generator 1 k in the subsequent reference mark signal r, that is to say whether the phase signal does not have the value 0. To do this, the η counter is first set to the value 0 (35) · Then the η counter is increased by the value 1 (36) until the value ZK is reached (37), i.e. a numerical value that corresponds to the distance between two reference mark signals r minus a correction factor K corresponds. If this value is exceeded, the appearance of a reference mark signal r is awaited (38). This is done by continuously running through the loop (3o to 39) and increasing the n-counter (36) accordingly until the value Z + K (39) is exceeded. If no reference mark signal r has appeared between ZK and Z + K, then there is an error that cannot be examined in this test step (ie it cannot be clearly determined whether a reference mark is missing

or whether there were no speed pulses due to a loose contact) and the test procedure is continued with method step 2k . If, on the other hand, a reference mark signal r (38) appears in the specified interval, the signal level simultaneously applied to the phase signal generator 1 k is examined (ItO). If this signal level is properly equal to 1, the main program, that is, the program for generating ignition, injection or other control signals, is stuck in a manner not shown. If, on the other hand, there is a signal level of. 0, a phase error signal (p-error 2) is generated ( kl ), which indicates that an incorrect phase signal is present, which is most likely due to a loose contact.

The following description starts again at loop 32 to 3k . If at the end of a phase signal (3k) still no reference mark signal r has occurred, a check is made as to whether there is a reference mark error. For this purpose, the η counter, which currently contains the value Zp, is incremented by the value 1 (k2) . The occurrence of a reference mark signal ■ r is then checked again (k3) . A loop (k2 to kk) waits until the numerical value 2Z + Zp is reached (kk) . This numerical value corresponds to twice the distance between two reference mark signals plus the numerical value Zp, which corresponds to the signal width of a phase signal. Here again the absence of a reference mark signal is initially tolerated
such toleration does not take place, so will
only up to the numerical value Z + Zp in the loop
(k2 to kk) remained. When the numerical value is reached, a reference mark error signal (U5) is stored and, if necessary, displayed, which indicates the defect in the

Reference mark encoder. Then a Any stored angle errors deleted (U6), which will be discussed later.

If, on the other hand, a reference mark signal r (U3) occurs while loop k2 ″ to kk , a check is now made to determine whether there is an angle error, i.e. whether the reference mark signal is angularly incorrectly rotated with respect to the phase signal. This can include, for example, a rotation of the distributor. First, another n1 counter is set to the value O (kj). Then a query is made as to whether the first η counter has exceeded the value Zp (^ 8). This should actually be the case, since this counter was already used during the If the numerical value is lower than Zp, there must be another error and the test starts again at step 2k . If, on the other hand, ^ the numerical value Zp is exceeded, the occurrence of a reference mark signal r is awaited again (^ 9 ) · This waiting takes place in a loop (U9 to 51) with the respective increment of the n1 counter by the value 1 (50) until the numerical value 2Z + K is exceeded (51) · Ist di if this is the case, there is a reference mark error which is saved (^ 5). If, on the other hand, a reference mark signal r (^ 9) occurs while the loop is running (U9 to 51), a query is made as to whether this reference mark signal occurred at the correct distance from the previous one (52). The correct distance is Z, again allowing a tolerance of at least -1. If the correct distance is not given, there is another error and the test starts again at step 2k . If, on the other hand, the distance is correct, a query is made as to whether a phase signal p = 0

at the same time the door is open (53). Since the previous reference mark signal (J + 3) did not coincide with a phase signal, a phase signal should now be present if the function was correct. If there is consequently no phase signal (53), an angle error (OC error) is stored and, if necessary, displayed (5M »which indicates that there is an angle error between the detection mark and the phase, which is due in particular to a twisting of the distributor.

In the flowchart shown in FIG. K , the test sequence (_68) shown schematically in FIG. 3 for detecting a speed signal error is shown in more detail. The purpose of this arrangement is to store a further speed error (n-error 2) and to maintain the storage even if a speed signal occurs later if, immediately after switching on the power supply, a regular sequence of p and r signals but no speed signal η occurs. It can happen that when the power supply is switched on, reference mark and phase signals are simulated by signal bouncing or other switch-on disturbances, without speed signals already being present at this point in time. If, on the other hand, the speed signals do not actually set in until after a few periods of proper reference mark and phase signals, then there is a speed error, which appears to be corrected when speed signals reappear, but basically contains an error in the speed sensor that must be investigated. For this purpose, a certain number of reference marks and phases are checked for their correct sequence and

-K-

A speed error is only saved if, after this correct sequence, there is still no Speed signal has occurred.

In the absence of a speed signal edge (23), a phase signal edge is therefore first waited for (55), namely a phase signal edge at the beginning of a phase signal (h6). A phase signal counter is then increased by the value 1 (57). Thereafter, the state of the phase signal generator 11; queried (58), which at this point in time has an O signal. Thereafter, a loop (59 to 63, 58) the occurrence of a reference mark signal r awaited (59) · If during such a passage, a speed flank (62), so no speed error signal is additionally stored and 2k in the manner already described by the step that already set speed error signal (η error l) deleted again. If a reference mark signal occurs (59) , a reference mark counter which only counts when p = 0 (6h) is increased by the value 1. If the phase signal is ended (58) in one of the subsequent runs of the loop described (58 to 63), a reference mark signal r is again waited for in test step (65). The waiting loop now consists of steps 60 to 63> 58, 65. If such a reference mark signal occurs, a reference mark counter, which only counts when p = 1 (66), is increased by the value 1. This reciprocal running through of the two loops described takes place until the condition specified in step 60 is met, i.e. until the reference mark counter (p = 0) has the value 2 and the reference mark counter (p = i) has the value 1 and the phase signal counter (p Counter) has the value 3. The phase signal counter (57) is increased whenever

387

AS

a p-edge occurs during a loop pass (.63). If the condition set in step βθ is met - if the order of the signals ρ and r according to FIG Step 2k is deleted. It indicates that when the control device 10 is switched on, there is an irregularity in the speed signals or that the speed signal was missing for a certain time due to a loose contact while the engine was running. If, on the other hand, this prescribed sequence of the p and r signals according to FIG. U is not adhered to, then it must be a question of interference and bounce signals; a speed edge (23) continues to be waited for.

It should be noted that the encoder described in place 13 and 1 hour of a signal can also make multiple signals per revolution. In the case of multi-cylinder internal combustion engines in particular, this depends on whether further required signals are to be generated internally electronically or by the transmitter arrangements. It should also be mentioned that the control device for calculating control signals can of course also be supplied with further required parameters in a known manner. This is shown symbolically by the arrow PM.

- blank page -

Claims (1)

y / ο Ο J »■ 18387- 1.3.1983 Ve / Kc ROBERT BOSCH GMBH, 7OOO Stuttgart 1 Expectations .j Device for displaying and / or storing errors in transmitter arrangements on internal combustion engines, a first signal transmitter (13) coupled to a shaft generating at least one reference mark (r) per revolution and at least one second signal transmitter ("\ k) being provided, whose signals are permanently assigned to the signals of the first transmitter, characterized in that if there is a deviation from a prescribed sequence and prescribed distances between reference marks and other signals, at least one error signal is generated, which is stored and / or fed to a display device (15) will. 2. Device according to claim 1, characterized in that that the first signal transmitter (13) with the crankshaft of the internal combustion engine and the second signal transmitter (1U) to Generation of phase signals is coupled to the camshaft. 3. Apparatus according to claim 1, characterized in that each n-th (n - 2) reference mark signal during a relatively longer phase signal is generated and that if there is a deviation from this prescribed coincidence an error signal is generated outside a specifiable tolerance. k. Device according to one of Claims 1 to 3, characterized in that the signal spacing between two signals is counted with the aid of speed signals (n) of higher frequency from a speed incremental encoder (12) and that if a predeterminable numerical value is exceeded, an error signal is generated for the signal to be tested . IV W -Ul I 5. Apparatus according to claim ^, characterized in that to check a phase signal (p), which after a coincidence with a reference mark signal (r) "must not occur in the subsequent reference mark signal, speed signals (n) are counted from the first reference mark signal, and that a phase error signal is generated in the subsequent reference mark signal and the phase signal occurring at the same time. D. Device according to one of claims 3 to 5 _S, characterized in that speed signals (n) are counted from the first edge of a phase signal (p) and that when a reference mark signal (r) occurs before a numerical value (Zp), which is the length corresponds to a phase signal, no error signal is generated and the system switches to the next test step. 7. Apparatus according to claim 6 _}, characterized in that when a predeterminable numerical value is reached which corresponds to at least the signal distance (Z) between two reference mark signals (r) without a warning mark signal having occurred, a reference mark error signal is generated. 8. Apparatus according to claim 7, characterized in that that when a reference mark signal occurs before the predeterminable numerical value is reached, another counting process is carried out is initiated by speed signals, and that when a further numerical value is reached, the corresponds to at least the signal distance between two reference mark signals without another If the reference mark signal had occurred, a reference mark error signal is generated. 9. Apparatus according to claim 8, characterized in that when a reference mark signal occurs in the provided Distance during the further counting process and the simultaneous absence of a phase signal Angle error signal is generated. 1Q.Vorrichtung according to any one of the preceding claims, characterized in that a speed error signal (1) is generated at the beginning of the test process, which at Occurrence of a speed signal edge is deleted again. 11. The device according to claim 10, characterized in that that when phase and reference mark signals and missing speed signals occur, a prescribed one Sequence of phase and reference mark signals is queried, and that -prescribed when this is present Sequence another speed error signal (2) is generated. 12. The device according to claim 1ί, characterized in that that the further speed error signal is also received when speed signals subsequently occur remain. 13. Device according to one of the preceding claims, characterized by implementation in a microcomputer (1 0). ¹ Ik. Device according to Claim 13, characterized in that a common microcomputer is provided for checking and / or storing as well as the control functions for the internal combustion engine.