ES2225296T3 - CONTROL METHOD FOR A VACUUM CLEANER. - Google Patents

Abstract

A control method for a vacuum cleaner (1) including a control means (7) to perform control algorithms, a motor (6) to drive a fan (8) that provides suction, a dust sensor (2) placed on the dust passageway and including a light emitter (3) and a light receiver (4) to detect dust passing through the dust passageway, and indication means (5) to give an indication to the user when the dust sensor (2) is dirty. The voltage variations pattern is observed at the light receiver (4) output and a series of comparisons are made in order to decide whether the place is dusty or the dust sensor (2) is dirty.

Description

Control method for a vacuum cleaner.

This invention relates to a method employed in vacuum cleaners to determine the degree of dirt in the place to be cleaned and of the dust detection components.

In the prior art, sensors are placed powder, consisting of optical components, specifically components light emitter and light receiver, in the dust duct of a Vacuum cleaner. The light emitting device is emitting a beam of infrared light or similar, and the light receiving device is receiving the light emitted by the light emitting device. These devices are arranged in a predetermined position in the air duct These light emitting and light receiving devices are placed opposite each other in fixed positions so that the change in light intensity indicates the amount of dust passing through the suction path. When these devices they are covered with dust, the light received decreases so it degrades the performance of the dust detection medium.

Under these circumstances, if the emitted light is keeps constant, then the amount of dust that passes through the duct can be determined, when the vacuum is in its ignition stage, according to the light received by the receiver. The light intensity received by the receiver decreases as increases the amount of dust that passes through the duct. This property is used to increase engine power while Dust is detected. Although this is an efficient way to determine the dust, as the dust is aspirated by the conduit, covers the surface of the sensors, which reduces the amount of light received even if no dust is passing.

In EP 0904723, a "sensitivity correction means" for solving this problem is described. The purpose of the method described in this patent is to increase the amount of light emitted by the emitter proportionally to the reduction of light caused by the adhesion of particles on the sensors. The problem with this method is that, if the amount of light emitted is increased when the window elements of the sensors are dirty, it reaches a limit value after a certain period, that is, the emitted light can no longer be increased. In this case, the window elements in the sensors must be cleaned by hand. The user is informed that the fouling of the window elements has increased so much that a correction of the light intensity emitted by the light emitting device reaches its limit value.
tea.

US 5152028 describes another method. The sensor surfaces are cleaned with the help of a mechanical device so that the light intensity is maintained constant. In this patent, a vertical vacuum is introduced that It includes a dust sensor. The problem explained above is solved by a cleaning element that cleans the surface of the window elements by means of the sliding movement of the vacuum cleaner. Since it is a vertical vacuum, the Sliding movement is achieved by the movement of the handle. When the handle reaches an angle of 90º, the sliding element covers the surface of the sensors. A drawback of this method is that when the degree of slippage is less than 90º, but not large enough to withdraw, the sliding element can partially cover the surface of the sensor, therefore, the luminous intensity can be reduced, so that, as result, the efficiency of the sensitivity means is will reduce.

The object of the present invention is to detect if The place being cleaned is covered with dust or not.

Another object of this invention is to determine if The dust sensor components are dirty or not.

The present invention is illustrated in the drawings, in which:

Figure 1 is the schematic view showing a general arrangement of a vacuum cleaner.

Figure 2 is the middle circuit diagram of detection according to the preferred embodiment of the present invention.

Figure 3 is the intensity chart luminous with respect to time when the sensor components of Dust are getting dirty.

Figure 4 is the graph of the difference value reference (Dref) with respect to light intensity received

Figure 5 is the flow chart of the method of control.

The components shown in the drawings have The following numbers:

1 - Vacuum cleaner

2 - Dust sensor

3 - Light emitter

4 - Light receiver

5 - Means of indication

6 - Engine

7 - Control medium

8 - Detection medium

9 - Fan

10 - Resistance

11 - Detection circuit

In the preferred embodiment of this invention, a vacuum cleaner (1) comprises a motor (6) to propel a fan (9) that provides the suction, a means (8) of detection to detect dust, an indication means (5), which It includes either LEDs or LCD displays to indicate when user that the dust sensor components are dirty, and a control means (7) that controls the motor (6).

The detection means (8) comprises a sensor (2) of dust placed in the dust duct to detect dust that passes through, and comprising two components, specifically, a light emitter (3), which is preferably a light emitting diode, and a light receiver (4), which is preferably a phototransistor, to detect the dust that passes through the dust duct, a resistance (10) R1 to determine the current to be introduced into the light emitter (3), and a detection circuit (11) for measuring light received by the light receiver (4) in terms of voltage or current depending on your disposition:

The supply voltage (Vx) on the side of light emission of the detection means (8), the resistance (10) R1 is choose so that the current that is applied to the light emitter (3) is always maximum and does not change during the operation of the vacuum cleaner (1) so that the intensity of the emitted light is maintained constant during operation of the vacuum cleaner (1).

When the vacuum is turned on (1) to clean one surface, the maximum current is applied to the light emitter (3) of the dust sensor (2) (101). This current does not change during operation of the vacuum cleaner (1). The receiver output (5) of Light is measured during predetermined time intervals. Every Time interval defines a cycle.

For a cycle n, while dust passes through the dust duct, the intensity of the light received by the receiver (4) of light fluctuates. Decreases at the moment the dust passes between the light emitter (3) and the light receiver (4) and increases in the moment in which no dust passes between the light emitter (3) and the light receiver (4). Figure 3 shows a graph of the probable light intensity with respect to time. According to the arrangement of the detection circuit (11), the intensity luminous can be measured in terms of voltage or in terms of current, and the measured voltage or current may increase or decrease with the dust that passes through the dust duct, that is, the measure voltage or current is proportionally or inversely proportional to the intensity of the light received by the receiver (4) of light. After observing the light intensity during cycle n, find and store (102) the max_ {1} (n) values, max_ {2} (n), ... max_ {i} (n) local maximums and values min_ {1} (n), min_ {2} (n), ... min_ {1} (n) local minimums of the light intensity. TO Then, the value (max (n)) is calculated and stored (103) average of the maximum local values and the value (min (n)) average of the local minimum values of the output data for the cycle n in the memory of the control means (7). Then it calculate (104) the difference (Delta (n)) between the value (max (n)) average of the maximum local values and the value (min (n)) average of the minimum local values.

The difference (Delta (n)) is compared then (106) with a value (Dref (n)) difference of default reference. Preferably the value (Dref (n)) reference difference depends on the value (min (n)) average of the minimum local values. For each probable value of the average value of the local minimum values of the light intensity, (min (n)), is retained in the memory of the control means (7) a value (Dref (n)) difference of different reference. While cleaning the surface, if the surface is dirty and / or if dust is adhered to components of the dust sensor (2), the average value of the values local minimums of the light intensity, (min (n)), will decrease, and fluctuations in the light intensity received They will also decrease. When fluctuations decrease, there is possibility of having values (Delta (n)) difference more small, therefore, (Dref (n)) is chosen as a small value to provide adaptation to the detection conditions and to be able to detect the presence of dust with a value (Delta (n)) smaller. The value (Dref (n)) differs reference can also be chosen as a constant value.

If the difference (Delta (n)) is greater than the value (Dref (n)) default reference difference, then the decision is that: "the place has dust", and it is decided to increase (107) the engine power ( 6). A new n + 1 cycle begins with a new start time interval, the light intensity is observed again, and an average value (max (n + 1)) of the local maximums and a value (min ( n + 1)) average of the local minimum values,
new.

If the difference (Delta (n)) is less than the value (Dref (n)) default reference difference, that is, if the fluctuations in the output data are not what large enough to indicate the presence of dust to cycle n, two possibilities are considered:

- The first possibility is that "the place does not it has dust ", so there will be no need to increase the engine power (6).

- The second possibility is that "the components of the dust sensor (2), the light emitter (3) and / or the light receiver (4) are dirty, and this causes an exit without the enough fluctuations to reflect the real state of the surface being cleaned ".

To make the decision between these two possibilities, the average value (min (n)) of the minimum values premises is compared with a minimum value (Dmin) of intensity light allowed, default, which is a constant value determined experimentally and stored in the unit (108) of memory.

If the average value (min (n)) of the values local minimums of the light intensity for cycle n is higher that the constant minimum value (Dmin) of the light intensity allowed, default, the decision is that there is no dust in the air sucked, that is, "the place has no dust", and it is decided keep the engine power constant (6) (109). The n + 1 cycle begins.

If the average value (min (n)) of the values local minimums of the light intensity for cycle n is lower that the minimum value (Dmin) of the permitted light intensity, default, and the number of cycles begins to be counted (110) consecutive in which the following conditions occur; the values (Delta) difference are smaller than values (Dref) reference difference, and the average (min) values of the values local minima are smaller than the minimum value (Dmin) of the light intensity allowed, predetermined, i.e. differences (Delta (n), Delta (n + 1), ... Delta (n + c)) are smaller than the values (Dref (n), Dref (n + 1), ... Dref (n + c)) reference difference, respectively, and each value (min (n), min (n + 1), ... min (n + c)) average of the minimum local values is less than the minimum value (Dmin) of the permitted light intensity, predetermined. Then the number of cycles counted is compare with c (111). If they are the same, that is, if the conditions above exist during c consecutive cycles, it is decided that "the components of the dust sensor, the light emitter (3) and the light receiver (4) are dirty ", and the user is notified by medium of the indication medium (5) and the n + c + 1 cycle begins.

Since a continuous flow of dust can cause an output with small fluctuations during some cycle (but not for as long as during cycles c), that is, with a difference (Delta) smaller than the value (Dref) reference difference and with an average value (min (n)) of the local minimum values smaller than the minimum value (Dmin) of the permitted light intensity, default, a decision about the degree of dirt of the sensor components of dust without being certain that it is caused by dust continuous. If the values (Delta (n), Delta (n + 1), ... Delta (n + c)) difference are smaller than values (Dref (n), Dref (n + 1), ... Dref (n + c)) difference of reference, respectively, and each value (min (n), min (n + 1), ... min (n + c)) average of the minimum values premises is less than the minimum value (Dmin) of the intensity light allowed, default, it is decided that this is caused by the degree of dirt of the sensor components (2) of dust.

Claims (6)

1. Control method for a vacuum cleaner (1) that includes a motor (6) to propel a fan (9) that provides the aspiration, a detection means (8), comprising a dust sensor (2) placed in the dust conduit having a light emitter (3), a light receiver (4) and a detection circuit (11) to detect the dust passing through the dust conduit, a control means (7) that controls the motor (6), and an indication means (5), comprising either LED diodes, or LCD displays, to indicate to the user that the components of the dust sensor (2) are dirty, characterized in that the method comprises the steps of turn on the vacuum (1) and apply the maximum current to the light emitter (3) and observe the light intensity in the light receiver (4) for a predetermined period of time that defines a cycle n (101), find and store some values (max_ {1} (n) ... max_ {i} (n)) local maximums and values (min_ {1} (n) ... min_ {i} (n) minimums local light intensity during cycle n (102), then calculate the average value (max (n)) of the local maximum values and the average value (min (n)) of the local minimum values (103), calculate the difference (Delta (n)) between the average value (max (n)) of the local maximum values and the average value (min (n)) of the local minimum values (104), obtain a corresponding value (Dref ( n)) reference difference that is stored in the memory of the control means (7) (105), compare the value (Delta (n)) difference with a value (Dref (n)) predetermined reference difference (106), if the value (Delta (n)) difference is greater than the value (Dref (n)) predetermined reference difference, decide that the place has dust (107) and increase the power of the motor (6) accordingly, and if the value (Delta (n)) difference is less than the value (Dref (n)) default reference difference, determine if the place is clean or if the dust sensor components is so dirty. 2. Control method for a vacuum cleaner (1) according to claim 1, characterized in that, in order to provide the adaptation to the detection conditions, the value (Dref (n)) predetermined reference difference depends on the value (min (n )) average of the local minimum values, so that the value (Dref) reference difference decreases while the average value (min) of the local minimum values decreases, in order to have a value (Dref (n)) reference difference smaller when fluctuations are smaller due to continuous dust or due to the adhesion of dust on the dust sensor components (2). 3. Control method for a vacuum cleaner (1) according to claim 2, characterized in that, if the value (Delta (n)) difference is less than the value (Dref (n)) predetermined reference difference during the predetermined period of time It also includes the steps of comparing the average value (min (n)) of the local minimum values with a constant minimum value (Dmin) of the allowed, predetermined light intensity, making a decision about the "absence of dust in the air aspirated "if the average value (min (n)) of the local minimum values of the light intensity is greater than the predetermined constant value (Dmin) (109), and keep the motor power (4) constant. 4. A control method for a vacuum cleaner (1) according to claim 3, characterized in that, if the average value (min (n)) of the local minimum values is less than the constant minimum (Dmin) value of the allowed, predetermined light intensity It also includes the steps of counting the number of consecutive cycles in which the following conditions occur (110); it is found that the values (Delta) difference are smaller than the values (Dref) reference difference, and it is found that the average values (min) of the local minimum values are smaller than the value (Dmin), that is, if the values (Delta (n), Delta (n + 1), ... Delta (n + c)) difference are smaller than the values (Dref (n), Dref (n + 1), ... Dref (n + c)) reference difference, respectively, and each value (min (n), min (n + 1), ... min (n + c)) average of the local minimum values is less than the value ( Dmin) minimum of the allowed light intensity, predetermined, then if the above conditions exist for c consecutive cycles, decide that "the components of the dust sensor, the light emitter (3) and the light receiver (4) are dirty" , and notify the user about the degree of dirt of the dust sensor (2) by means of the indication means (3). 5. Control method for a vacuum cleaner (1) according to claim 4, characterized in that the output at the light receiver (4) is measured in terms of voltage or current, and the detection circuit (11) is arranged so that the measured voltage value is (directly or inversely) proportional to the light intensity. 6. Vacuum cleaner that uses a control method according to any of claims 1 to 5.