DE4433350C1 - Fuzzy inference processor rule processing apparatus - Google Patents

Abstract

The subject of the application is a device in which two numbers (r1, r2) for relevance functions, two control bits (nb1, nbr), a number (ne0) of a lower linguistic word and a measurement (me0, me1) of the relevance functions of the lower and an upper linguistic word are used to form a value (me) of the logical linking of relevance functions of the linguistic word occurring in the condition section in such a way that the condition section of a rule can also contain NOT, OR and AND-linked linguistic values of the input variables. The advantage obtained here, especially with extensive linguistic protocols, lies in smaller storage space and a higher processing rate than in prior art fuzzy logic processors and in the facility for coding an additional linguistic value.

Description

In many cases, fuzzy rules become linguistic NOT, OR and AND operators are required to make rules effi to formulate or program more efficiently than in the normal form

if A = A _i and B = B _k and. . . then V = V₁.

Here, NOT, OR and AND operations between membership functions µ _i and µ _{k of} two generally non-adjacent linguistic values of a respective input variable, such as the linguistic values Ai and Ak of the input variable A, as well as combinations of these operations are necessary.

Circuits for fuzzy inference processors are for example known from US 5 299 283 or EP 0 544 629 A2.

The object on which the invention is based is now to provide a device for a fuzzy logic processor, where the linguistic NOT, OR and AND operators are directly processable in order, especially with extensive linguistic protocols, storage space or chip area and Save computing time.

This object is achieved by the features of Pa claim 1 solved.

A particular advantage of the invention is that for the case that an input variable does not exist in a rule occurs, no own coding must be provided because this case can be formulated through the operations mentioned, whereby, given a fixed number of possible Coding states, an additional linguistic value is available.  

The claims 2 to 4 relate to advantageous Ausgestal lines of the device according to the invention.

The invention is based on the drawing he he purifies. It shows

Fig. 1 is a block diagram of a Vorrich device according to the invention and

FIG. 2 is a diagram for explaining the functioning of the device according to FIG. 1.

In Fig. 1 is a block diagram of a device according to the invention with a comparator unit CNR, of a unit for forming selection conditions BM and a selection unit M is shown. The device or the comparator unit CNR becomes a number r1 and a further number r2 for a linguistic value of the input variable in the respective rule and a number ne0 for a lower linguistic value of the input variable, which is hit by a respective sharp input value of the fuzzy inference processor fed. A number ne1 for an upper hit linguistic value of the input variables is formed in an incrementer in the comparator unit, this being done by adding a one to the number for the lower hit linguistic value. Comparison results e0 to e10 are formed in the comparator unit CNR, the result e0 a comparison r2 <r1, the result e1 a comparison r2 = r1, the result e2 a comparison r2 <r1, the result e3 a comparison r2 = ne1, the result e4 a comparison r1 = ne1, the result e5 a comparison r2 = ne0, the result e6 a comparison r1 = ne0, the result e7 a comparison r2 <ne1, the result e8 a comparison r1 <ne1, the result e9 a comparison r2 < ne0 and the result e10 corresponds to a comparison r1 <ne0.

In the unit for the creation of selection conditions BM is made Comparison results and the left-hand negation bit nbl and the right-hand negation bit nbr a selection condition a0 after the relationship

a0 = e0∧ [e3∧¬nbl∨e4∧¬e5] ∨ el∧ [e3∧nbl∨e6∧¬nbl∧¬nbr] ∨ e2∧ [(¬e3∨nbr) ∧e6∧¬nbl∨e4∧nbl∨e5∧¬nbr]

a selection condition a1 according to the relationship

a1 = e0∧ [e6∧¬nbr∨¬e4∧e5] ∨ e1∧ [e6∧nbr∨e3∧¬nbl∧¬nbr] ∨ e2∧ [(¬e6∨nbl) ∧e3∧¬nbr∨e5∧nbr∨e4∧¬nbl]

a selection condition a2 according to the relationship

a2 = e0∧ [e7∧¬nbl∨e8∧e9∨e10∧¬nbr] ∨ e1∧ [e7∧nbl∨e10∧nbr] ∨
e2∧ [e8∧nbl∨e9∧nbr] and

a selection condition a3 according to the relationship

a3 = e2∧e3∧e6∧¬nbl∧¬nbr

formed, as usual

¬ a negation,
UND an AND operation and
∨ an OR operation

means.

The selection unit M becomes a value me0 of membership function of the lower linguistic value of the Input variables and a value me1 of the membership function of an upper linguistic value of the On gear variables supplied. An initial value me of the selection Unit M simultaneously represents the initial value of the fiction represent device.  

The selection unit M essentially consists of a multi plexer, a unit for forming a fuzzy OR ver link and a unit to form a fuzzy AND link. The selection unit M is so constructed that the initial value never the value me0 of the membership function of the lower linguistic value hit is when the Selection condition a0 is fulfilled, equal to the value of an un sharp OR link (OR (me0, me1)) of membership functions of the lower upper hit linguistic The value is the same if the selection condition a2 is fulfilled the value of an unsharp AND operation (AND (me0, me1)) Membership functions of the lower upper hit is linguistic value if the selection condition a3 er is filled, and otherwise the value (me1) of the associated function of the upper linguistic value hit is.

The fuzzy OR operation can be, for example, in Form a maximum formation or the formation of a limited Sum and the fuzzy AND link, for example in Formed a minimum formation or a product formation his.

The selection unit can advantageously also be selected from the Selection signals a0 to a3 hit a hit signal thereby bil that the selection signals a0. . . a3 OR-linked. With a hit signal hit = 0 is followed by one of the devices switched rule evaluation part informed that the from sharp value of the input variable hit linguisti values in none of the codes coded in the respective rule Link occur that the condition part of this Re does not apply to the present input variable is filling. The rule downstream of the device Then the value me = me1 is transferred, but there because of the hit signal hit = 0, not "no hit" processed further.  

Furthermore, the device can advantageously be a switching network S included, in which a signal sm for determining an in the input variable that does not occur in the respective rule is witnessed, this by an AND operation of the Ver same result e1, the left-hand negation bit nbl and the negated right-hand negation bit nbr and the negated bits of the number r2 happens. Linking the negated bits of the number r2 here mean that a Si gnal sm = 1, if at all, only occurs for the case r2 = 000.

Correspondingly, in the switching network S is used to generate a signal to determine a not found in the respective rule input variables also an AND operation of the ver same result e1, the negated left-hand negation bits nbl and the right-hand negation bit nbr and the Bits of number r2 possible. Linking the non negatives Ten bits of the number r2 here mean that a signal sm = 1, if at all, only occurs for the case r2 = 111.

The invention is not based on the examples given here maximum degree of overlap ü = 2 limited and can also be used in fuzzy inference processors that more than only a maximum of two linguistic values hit at the same time allow, where, with a degree of overlap ü = λ + 1, of an upstream fuzzy unit, values me0, me1,. . . meλ are delivered and the unsharp AND and OR Links in the selection circuit M up to λ + 1 arguments exhibit.

In Fig. 2 is a diagram for explaining the function of the device shown in Fig. 1, device according to the invention is shown, with the three cases r2 = r1 = r, r2 <r1, and r2 <r1 as a rough structure and right in a left column in addition, all four possible value combinations of the two negation bits nbl and nbr are plotted in sequence. Starting with the coding r2 = r1, nbl = 0, nbr = 0 and ending with the coding r2 <r1, nbl = 1 and nbr = 1, the following important links can be selected in order:

where ne is the number of a respective linguistic value represents an input variable.

The negation bits nbl and nbr as well as the numbers r1 and r2 could encode not only the selection of important links given above, but also another selection of 3 _* 4 = 12 links from all conceivable links of all possible linguistic values of a respective linguistic input variable .

In addition, there is also a coding with more think of as two negation bits and / or more than two numbers bar.

Claims (4)

1. Device in a fuzzy inference processor, in which a comparator unit (CNR), a unit for forming selection conditions (BM) and a selection unit (M) are provided,
in which the comparator unit (CNR) is supplied with a number r1 and a number r2 for a linguistic value of a respective input variable in the respective rule and a number ne0 for a lower linguistic value of the respective input variable, there a number ne1 for an upper one The linguistic value of the respective input variable that has been hit is formed by adding a one to the number for the lower linguistic value that has been hit, and comparison results e0 to e10 are formed in the comparator unit (CNR), the result e0 being a comparison r2 <r1 and the result e1 being a comparison r2 = r1, the result e2 a comparison r2 <r1, the result e3 a comparison r2 = ne1, the result e4 a comparison r1 = ne1, the result e5 a comparison r2 = ne0, the result e6 a comparison r1 = ne0, the Result e7 a comparison r2 <ne1, the result e8 a comparison r1 <ne1, the result e9 a comparison r2 <ne0 and the result e 10 corresponds to a comparison r1 <ne0,
in the unit for forming selection conditions (BM) from comparison results and the left-hand and right-hand negation bits nbl and nbr, a selection condition a0 according to the relationship a0 = e0 Bildung [e3∧¬nbl∨e4∧¬e5] ∨ e1∧ [e3∧ nbl∨e6∧¬nbl∧¬nbr] ∨ e2∧ [(¬e3∨nbr) ∧e6∧¬nbl∨e4∧nbl∨e5∧¬nbr] a selection condition a1 according to the relationship a1 = e0∧ [e6∧¬nbr∨ ¬e4∧e5] ∨ e1∧ [e6∧nbr∨e3∧¬nbl∧¬nbr] ∨ e2∧ [(¬e6∨nbl) ∧e3∧¬nbr∨e5∧nbr∨e4∧¬nbl] according to a selection condition a2 of the relationship a2 = e0∧ [e7∧¬nbl∨e8∧e9∨e10∧¬nbr] ∨ e1∧ [e7∧nbl∨e10∧nbr] ∨ e2∧ [e8∧nbl∨e9∧nbr] and a selection condition a3 according to the relationship a3 = e2∧e3∧e6∧¬nbl∧¬nbr is formed,
in which the selection unit (M) is supplied with a value (me0) of the membership function of the lower linguistic value of the respective input variable, a value (me1) of the membership function of an upper linguistic value of the respective input variable and in which an output value (me) is the value (me0) of the membership function of the lower linguistic value that is met, if the selection condition a0 is fulfilled, is equal to the value of an unsharp OR operation (OR (me0, me1)) of the membership functions of the lower and upper linguistic value that is met, if the selection condition a2 is fulfilled, it is equal to the value of an unsharp AND operation (AND (me0, me1)) of the membership functions of the lower and upper linguistic value hit, if the selection condition a3 is fulfilled, and otherwise equal to the value (me1 ) is the membership function of the upper linistic value hit. 2. Device according to claim 1, in which the selection signals a0 to a3 become a hit signal (hit) are OR-linked, the hit signal indicating that the condition part of the respective rule with regard to each input variables are met. 3. Device according to claim 1 or 2, in which in a switching network (S) a signal for detection an input Va that does not occur in the respective rule riablen by an AND operation of the comparison result e1, the left-hand negation bit nbl and the negated right-hand negation bit nbr and the individual negated Bits number r2 is formed. 4. Device according to one of the preceding claims, in which the fuzzy OR operation in the form of a maximum education or the formation of a limited sum  and the fuzzy AND link in the form of a minimum image development or product formation.