JPH03158111A - Rice cooker - Google Patents

Abstract

PURPOSE:To carry out optimum rice cooking by providing a driving unit, etc., by which a switching element is driven in accordance with the electrification ratio determined by a fuzzy inference unit, so that the electrification ratio of a heating means can be determined by a fuzzy inference. CONSTITUTION:The determination of an electrification ratio is carried out by inputting the detected value of a temperature detecting element 4 for reasoning and determining the electrification ratio by means of a fuzzy inference unit 6. In accordance with the determined electrification ratio, a driving unit 7 drives a switching element by which a heating means 3 is constituted. In this case, the fuzzy inference unit 6 and the driving unit 7 can be easily realized by a microcomputer. In the inference, after respective conclusions with regard to all the rules stored in an electrification ratio inferential rule storing means 12 have been obtained, the maximum of all the conclusions is taken by a center- of-gravity calculating means 11 for obtaining the center of gravity, and as the final conclusion the electrification ratio to the heating means can be obtained. By the fuzzy inference like this, fine determination of electrification ratio in response to the load can be carried out, and optimum cooking can be performed.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a rice cooker that enables optimum rice cooking.

BACKGROUND OF THE INVENTION An example of a method for determining the energization ratio to heating means in a conventional rice cooker will be described below. When the cooking process begins, the energization ratio is set to 100% to rapidly heat the rice, and the subsequent energization ratio α is determined from the temperature gradient θ when a predetermined temperature is reached. At this time, the determination of α is α = a book θ + b ... (1
) was based on the linear form.

Problems to be Solved by the Invention However, the equation (1) above is for an ideal case, and in reality, the relationship is not as linear as the equation (1) due to the characteristics of the temperature detection element, the installation position, etc. That is, there was a problem that the energization ratio determined based on equation (1) was not optimal.

Therefore, the present invention aims to solve such conventional problems, and aims to provide a rice cooker that determines the energization ratio of the heating means by fuzzy reasoning and cooks rice optimally. .

Means for Solving the Problems In order to achieve the above objects, the present invention provides a heating means having a heating device such as a heater, a switching element such as a triac for controlling the energization ratio of the heating device, and A temperature detection element such as a thermistor that detects temperature, a fuzzy inference device that determines the energization ratio from the detected value of the temperature detection element, and a drive that drives the switching element according to the energization ratio determined by the fuzzy inference device. This is a rice cooker equipped with a device.

Effects The effects of the above means are as follows. That is, the fuzzy reasoner determines an appropriate energization ratio for the heating means based on the temperature of the food detected by the temperature detection element. The driving device drives the switching element according to the determined energization ratio to cook rice. At this time, by equipping the fuzzy reasoner with rice cooking know-how that humans know from experience, the rice cooking can be made optimal.

Embodiment An embodiment of the present invention will be described with reference to FIGS. 1 to 6. The food to be cooked is heated through the pot 2 by the heating means 3 provided at the bottom of the main body 1. The heating means 3 is composed of a heating device such as a heater and a switching element such as a triac that controls the energization ratio of the heating device. Reference numeral 4 denotes a temperature detection element such as a thermistor, which detects the temperature of the food to be cooked via the pot 2.

5 is a lid that prevents heat radiation.

Next, the determination of the energization ratio will be explained based on FIG. 1.

The energization ratio is determined by using the detected value of the temperature detecting element 4 as input and making an inference decision using the fuzzy inference device 6. The drive device 7 drives the switching elements constituting the heating means 3 according to the determined energization ratio. At this time,
The fuzzy inference device 6 and the driving device 7 can be easily realized with a microcomputer.

An example of fuzzy inference will be explained based on FIGS. 3 to 6. FIG. 3 shows temperature changes detected by the temperature detection element 4 during rice cooking. In the cooking process, the energization ratio is set to 100%, and the temperature gradient θ when the predetermined temperature T1 is reached.
Detect. This can be easily obtained by differentiating the detected value of the temperature detection element 4. From this temperature gradient θ, the subsequent energization ratio is determined by fuzzy reasoning. For example, the inference rule is ``If the temperature gradient θ is large, reduce the energization ratio.

”, which consists of three rules shown in Figure 4.

Qualitative concepts such as the temperature gradient θ being "large" or the energization ratio being "small" are expressed quantitatively by the membership functions shown in FIGS. 5(a) and 5(b). At this time, the inference rules and membership functions can be designed empirically or experimentally.

Next, a method of inference calculation will be described. FIG. 6 shows the specific configuration of the fuzzy inference unit 8. This will be explained below using the same figure. First, the energization ratio inference rule storage means 12
According to the rules stored in the temperature gradient membership function storage means 10, the temperature gradient compatibility calculation means 9 calculates the membership function stored in the temperature gradient membership function storage means 10 and MAX for the input, that is, the change in the detected value of the temperature detection element 4. The goodness of fit of the antecedent part is determined by Next, the consequent part minimum calculation means 13 takes the MIN of the membership function stored in the energization ratio membership function storage means 14 and the antecedent part fitness, and determines the conclusion of the rule. moreover,
After determining the respective conclusions for all the rules stored in the energization ratio inference rule storage means 12, the center of gravity calculating means 11 takes the MAX of all the conclusions, and by determining the center of gravity, the heating means is determined as the final conclusion.・A current conduction ratio of ＼ can be obtained.

According to such fuzzy reasoning, it is possible to determine the energization ratio in detail according to the load, and it is possible to perform optimal cooking.

The above has explained how to determine the energization ratio for the rice cooking process of the rice cooker, but similarly for the pre-cooking and additional cooking processes, the energization ratio for each process can be optimally determined by fuzzy reasoning using the detected value of the temperature detection element 4 as input. Needless to say, it is possible to determine In this embodiment, the consequent variable of the fuzzy inference is a general triangular type, but it is also possible to implement it using real values or functions.

As described in detail, according to the present invention, the energization ratio of the heating means is determined by fuzzy reasoning from the temperature state of the object to be heated, so that detailed and optimal rice cooking can be performed. This is because the know-how of rice cooking that one person knows from experience can be easily provided to the fuzzy reasoner.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a block diagram of the embodiment, Fig. 3 is a diagram showing temperature changes during the rice cooking process, and Fig. 4 shows the rules of fuzzy inference. figure,
Figure 5 is a diagram showing the membership function of fuzzy inference,
FIG. 6 is a diagram showing the configuration of the fuzzy inference device. 1... Main body, 2... Pot, 3... Heating means, 4...
- Temperature detection element, 6... Fuzzy inference device, 7... Drive device, 8... Microcomputer.

Claims (1)

[Claims] A heating means having a heating device such as a heater, a switching element such as a triac that controls the energization ratio of this heating device, a temperature detection element such as a thermistor that detects the temperature of the food to be cooked, and detection of this temperature detection element. A rice cooker comprising: a fuzzy inference device that determines an energization ratio from a value; and a drive device that drives the switching element according to the energization ratio determined by the fuzzy inference device.