KR100588059B1 - A non-contact close obstacle detection device for a cleaning robot - Google Patents

Abstract

A non-contact obstacle detection apparatus for a cleaning robot is disclosed that drives a plurality of IR sensors using one oscillator, driver, amplifier, and filter using a time division method.

The non-contact obstacle detecting apparatus of the cleaning robot according to the present invention is to detect an obstacle and operate while avoiding collision with the obstacle. When n is a predetermined natural number, the non-contact obstacle detecting apparatus of the cleaning robot having n infrared sensors is provided. In the present invention, the n-infrared sensor is time-divisionally controlled so that each n-infrared sensor sequentially outputs infrared rays, and the obstacles are detected by sequentially detecting infrared rays emitted in sequence with the transmission control unit 10. A reception control unit 12 which controls to read whether there is an error, and outputs infrared rays for sequentially detecting obstacles using the n-th sensor driving signal to n sensors, and sequentially n by using the n-shifted signal. Sensor unit 14 for detecting the presence of obstacles by reading the infrared rays from the first sensor; The transmission control unit 10, the counter 102 which outputs a n number of the count signal by counting the pulse signal is the first phase signal (Phase A) frequency divider divides a clock signal of constant frequency; A decoder 104 for decoding n count signals output from the counter 102 and outputting an n th sensor operation control signal; A logic end unit 106 for logically ANDing the n-th sensor operation control signal and the clock signal output from the decoder 104 to sequentially output the n-th sensor driving signal at the rising edge of the first phase signal; And a load signal RCLK for loading data from the shift register 124 based on the first phase signal Phase A and the count signal and having a predetermined phase difference from the first phase signal Phase A. And a reception control signal generator 108 for generating a shift signal SRCLK for the shift command of the shift register 124 based on the second phase signal Phase B, which is delayed in phase. The latch unit 122 may latch the first phase signal Phase A and the sensor driving signal IR_SIG; And sequentially input the latch signal, load the latched signal using the load signal RCLK, read data from the rising edge of the second phase signal Phase B using the shift signal SRCLK, and read the first phase signal. And a shift register 124 for shifting n at the falling edge of (Phase A).

Cleaning Robot, IR Sensor, Non-contact Sensor, Proximity Sensor, Time Division, Mobile Robot

Description

A non-contact close obstacle detection device for a Cleaning robot}

1 is a block diagram showing the structure of a non-contact obstacle detecting apparatus for a cleaning robot according to an embodiment of the present invention;

2 is a circuit diagram illustrating an example of the transmission control unit 10 of FIG. 1;

3 is a circuit diagram illustrating an example of the reception controller 10 of FIG. 1;

4 and 5 are waveform diagrams for explaining the operation of the circuit of FIG.

6 is a circuit diagram showing an example of a circuit that can be added for blocking external light;

7 is a circuit diagram showing an example of a receiving circuit portion of the sensor portion 14;

The present invention relates to a non-contact obstacle detection device of a cleaning robot that performs cleaning in a predetermined path, and more particularly, by using a time division method to overcome such disadvantages and using only one oscillator, driver, amplifier, and filter. It relates to a non-contact obstacle detection device of a cleaning robot for driving a plurality of IR sensors.

Cleaning robots that operate with various algorithms by combining sensing technology and vacuum cleaners that have been realized at present are being developed and marketed. Conventional cleaning robots have been developed to operate by avoiding a collision in advance by detecting an obstacle in the path by emitting an ultrasonic firing signal used in the submarine. In addition, other types of cleaning robots detect infrared sensors to avoid obstacles.

For mobile robots, obstacle detection capability is very important. The ability to detect obstacles must be in place for collision avoidance and self position awareness. A wide variety of sensors are used to detect obstacles.

Obstacle detection capabilities can be classified into various categories, the most basic and last of which is the non-contact proximity obstacle sensor that detects proximity obstacles of several centimeters or less. Non-contact sensors for detecting nearby obstacles include ultrasonic sensors, infrared sensors (hereinafter referred to as IR sensors), laser sensors, PSD sensors, capacitive sensors, hall sensors, cameras, and many other types of sensors. Has advantages and disadvantages Most of these sensors use a small number of sensors because they have a small area to be detected. It is very expensive to install many of these sensors because most of them are expensive, but it is an inevitable choice for robot safety. Among these sensors, the lowest cost and simplest to implement is an IR sensor, and most mobile robots use an IR sensor as a proximity obstacle sensor.

The basic operating principle of the IR sensor is equipped with a transmitter for transmitting infrared rays and a receiver for receiving reflected infrared rays to determine the presence or absence of the obstacle according to the amount of reflected light reflected by the obstacle.

In general, the configuration of the transmitter is frequency-modulated so as not to be interfered with by an external light source, and is composed of an oscillator and a driver as shown in FIG. 1. It will be equipped with a very large amplifier and narrowband filter to accept the fine signal from the receiver.

The IR sensor has a very narrow operating area due to the infrared characteristics, and therefore, a large number of sensors must be mounted around the robot when mounted on the robot. Therefore, a large number of oscillators, drivers, amplifiers, and filters are required for the transmission and reception circuit of the IR sensor, and there is a demand to lower the cost.

The technical problem to be achieved by the present invention relates to a cleaning robot that overcomes these disadvantages by using a time division method and drives a plurality of IR sensors using only one oscillator, driver, amplifier and filter.

The non-contact obstacle detecting apparatus of the cleaning robot according to the present invention for achieving the above technical problem is to operate while avoiding collision with the obstacle by detecting the obstacle, when n is a predetermined natural number for cleaning provided with n infrared sensors In the non-contact obstacle detection device of the robot,

Time division control of the n infrared sensors to control the n infrared sensors to sequentially output the infrared and the transmission control unit 10 in conjunction with the transmission control unit 10 detects the infrared rays emitted sequentially to see if there are any obstacles A reception control unit 12 controlling reading, and an infrared ray for sequentially detecting an obstacle using the nth sensor driving signal for n sensors, and an nth sensor sequentially using an n shifted signal The sensor unit 14 for detecting the presence of obstacles by reading the infrared rays from the;

The transmission control unit 10,

A counter 102 for dividing a clock signal having a constant frequency, counting a first phase signal Phase A, which is a divided pulse signal, and outputting n count signals;

A decoder 104 for decoding n count signals output from the counter 102 and outputting an n th sensor operation control signal;

A logic end unit 106 for logically ANDing the n-th sensor operation control signal and the clock signal output from the decoder 104 to sequentially output the n-th sensor driving signal at the rising edge of the first phase signal; And

Based on the first phase signal Phase A and the count signal, a load signal RCLK for generating data from the shift register 124 is generated and phased to have a predetermined phase difference from the first phase signal Phase A. A reception control signal generator 108 generating a shift signal SRCLK for a shift command of the shift register 124 based on the delayed second phase signal Phase B,

The reception control unit 12,

A latch unit 122 for latching the first phase signal Phase A and the sensor driving signal IR_SIG; And

The latch signal is sequentially input, but the latched signal is loaded using the load signal RCLK, the data is read from the rising edge of the second phase signal Phase B using the shift signal SRCLK, and the first phase signal ( And a shift register 124 for shifting n at the falling edge of phase A).

In addition, the sensor unit,

a light emitting diode configured to output infrared rays for sequentially detecting obstacles using n-th sensor driving signals for n sensors; And

It is possible to include; a light receiving transistor positioned so that the reception angle has a predetermined angle with respect to the firing angle of the infrared light output from the light emitting diode.

In addition, the first phase signal Phase A is used to emit infrared rays, and the second phase signal Phase B is used to receive infrared rays, and the first phase signal Phase A is converted to the counter 102. It is preferable to count and index by).

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the structure of a non-contact obstacle detecting apparatus for a cleaning robot according to an embodiment of the present invention, Figure 2 is a circuit diagram showing an example of the transmission control unit 10 of Figure 1, Figure 3 is Figure 1 4 and 5 are waveform diagrams for describing the operation of the circuit of FIG. 2.

1 and 2, the non-contact obstacle detecting apparatus of the cleaning robot according to the present invention is to detect an obstacle and operate while avoiding collision with the obstacle. When n is a predetermined natural number, n infrared sensors are used. In the non-contact obstacle detection device of the cleaning robot provided,

Time division control of the n infrared sensors to control the n infrared sensors to sequentially output the infrared and the transmission control unit 10 in conjunction with the transmission control unit 10 detects the infrared rays emitted sequentially to see if there are any obstacles A reception control unit 12 for controlling reading, and an infrared ray for sequentially detecting an obstacle by using the n-th sensor driving signal to n sensors, and sequentially by the n-th sensor using an n-shifted signal. It is provided with a sensor unit 14 for detecting the presence of obstacles by reading the infrared. In this embodiment, n is 8, the counter is an octal counter, the decoder is a 3: 8 decoder, and the shift register is an 8-shift register. In addition, according to the present invention, a clock signal is used to oscillate at a constant frequency to emit infrared rays to prevent disturbance of sunlight once.

The transmission control unit 10 includes a counter 102 and a decoder 104. The counter 104 divides a clock signal of a constant frequency, counts a first phase signal Phase A, which is a divided pulse signal, and outputs n count signals. In other words, the first phase signal Phase A is used to emit infrared light, and the second phase signal Phase B is used to receive infrared light, and the first phase signal Phase A is received by the counter 102. By counting) and indexing the counted order to determine the order of the sensor operation. The decoder 104 decodes n count signals output from the counter 102 and outputs an n th sensor operation control signal.

Next, the logic end unit 106 logic-ends the n-th sensor operation control signal and the clock signal output from the decoder 104 to sequentially n-th sensor driving signal at the rising edge (A time point) of the first phase signal. Outputs That is, the logic AND unit 106 ANDs the first phase signal Phase A signal and the clock signal and outputs a burst waveform (Burst signal or Firing signal) used as a driver input to actually emit infrared rays.

The reception control signal generator 108 generates a load signal RCLK for loading data from the shift register 124 based on the first phase signal Phase A and the count signal, and generates the first phase signal Phase A. The shift signal SRCLK is generated for the shift command of the shift register 124 based on the second phase signal Phase B, which is delayed to have a phase difference of about 90 degrees. The second phase signal Phase B may be made simply by inputting the first phase signal Phase A using a flip-flop (not shown).

Next, the latch unit 122 of the reception control unit 12 latches the first phase signal Phase A and the sensor driving signal IR_SIG, and the shift register 124 sequentially inputs the latch signal, but the load signal ( Load the latched signal using RCLK, read data from the rising edge (point B) of the second phase signal Phase B using the shift signal SRCLK, and the falling edge of the first phase signal Phase A. Shift n at (C time point).

That is, a burst signal or firing signal for emitting light from the infrared sensor is configured as eight clocks. The number of periodic signals constituting the clock signal is determined according to the sensitivity of the amplifier. In the case of an amplifier measuring the amplitude threshold, the number of clocks in the burst signal will be determined by the time constant value and the clock frequency of the charging capacitor. During the burst signal, eight first phase signals Phase A and Phase B, which are control signals for time division, are also generated. At this time, a burst signal is generated for each sensor by the counters 102 and 202 and the decoders 104 and 204 at the rising edge and the falling edge of the first phase signal Phase A and Phase B, respectively. Then, the shift operation by the shift registers 124 and 224 occurs to operate eight sensors in time division.

Next, the decoder is operated using a counter value in a section A, which is a rising edge of the first phase signal Phase A, so that an infrared firing signal is output to a desired infrared sensor, and the second phase signal Phase B The data is read through the shift register in the B section, which is the rising edge, and the shift register is shifted in the C section, which is the falling edge of the first phase signal Phase A. While clearing the value of the D-latch for reading the signal input from the D section, the falling edge of the second phase signal Phase B, when the overflow of eight counters occurs, the information of all the sensors is obtained. It is desirable to make the operation to turn over to.

The sensor unit 14 is output from a light emitting diode (not shown) and the light emitting diode (not shown) for outputting infrared rays for sequentially detecting an obstacle with respect to n sensors using the nth sensor driving signal. A light receiving transistor (not shown) is positioned so that the reception angle has a constant angle with respect to the firing angle of the infrared rays. For example, the structure of the sensor is installed side-by-side with the light emitting diode and the light receiving transistor facing each other, but the detectable length varies considerably depending on the characteristics of the reflector. It is desirable to give an angle. Depending on the angle and the distance between the two sensors, the detectable length is changed.For example, when the angle is 40 degrees and the length is 9mm, there is a slight difference depending on the material of the reflector. do. If you want to eliminate the difference in reflector material, you can increase the depth of mounting each sensor.

6 is a circuit diagram illustrating an example of a circuit that may be added to block external light. If interference by an external light source such as sunlight is severe and a reflected signal is not detected and a DC component due to disturbance is not detected due to saturation, a desired signal and DC component may be removed using a circuit as shown in FIG. 6. have. Since the DC signal is removed, the primary amplifier can be implemented using only a resistor without the need for a capacitor or the like in the feedback stage. A second amplifier may be mounted on the rear end of the primary amplifier in the same form to amplify the signal. However, in the present invention, the LM567 may be used to simultaneously perform a role of an amplifier with a narrowband filter. In addition, when the LM567 is used, a clock signal can be generated without a separate oscillation circuit like the circuit of FIG. 7. 7 is a circuit diagram showing an example of the receiving circuit portion of the sensor portion 14. The input can use a phototransistor to obtain an input current approximately proportional to the amount of light. It is also possible to use a photodiode rather than a phototransistor. At this point, at a point A, a voltage proportional to the amount of light can be obtained through a resistor connected to the emitters of the transistors Tr.1, Tr.2, ..., Tr.n. Since the amount of light is a mixture of the amount of modulated light and the disturbance light that are actual signal sources, only the desired signal can be obtained at the point B through the DC block.

The non-contact obstacle detecting apparatus of the cleaning robot according to the present invention as described above can implement a plurality of IR sensors as one driving circuit without using an oscillation circuit or an amplification circuit for each infrared sensor. In addition, since the circuits used for time division are implemented with simple logic gates, they can be easily implemented as EPLDs or programmable field-programmable gate arrays (FPGAs). Most circuits developed in recent years can be easily integrated with these ICs. According to the effect of the present invention, not only the component cost can be reduced, but also the power consumption required to drive the sensor can be reduced by the number of sensors installed. In addition, tuning the amplifier only needs to be done once, simplifying the manufacturing process.

As described above, the non-contact obstacle detecting apparatus of the cleaning robot according to the present invention can realize a plurality of IR sensors as a single driving circuit without using an oscillation circuit or an amplifying circuit for each infrared sensor, thereby reducing component cost as well as sensors. It also reduces the power required to drive the amplifier, and requires only one tuning of the amplifier, which simplifies the manufacturing process and dramatically increases productivity.

Claims (3)

In the non-contact obstacle detection device for a cleaning robot provided with n infrared sensors when n is a predetermined natural number to operate while avoiding the collision with the obstacle, Time division control of the n infrared sensors to control the n infrared sensors to sequentially output the infrared and the transmission control unit 10 in conjunction with the transmission control unit 10 detects the infrared rays emitted sequentially to see if there are any obstacles A reception control unit 12 for controlling reading, and an infrared ray for sequentially detecting an obstacle by using the n-th sensor driving signal to n sensors, and sequentially by the n-th sensor using an n-shifted signal. Sensor unit 14 for detecting the presence of obstacles by reading the infrared; The transmission control unit 10, A counter 102 for dividing a clock signal having a constant frequency, counting a first phase signal Phase A, which is a divided pulse signal, and outputting n count signals; A decoder 104 for decoding n count signals output from the counter 102 and outputting an n th sensor operation control signal; A logic end unit 106 for logically ANDing the n-th sensor operation control signal and the clock signal output from the decoder 104 to sequentially output the n-th sensor driving signal at the rising edge of the first phase signal; And Based on the first phase signal Phase A and the count signal, a load signal RCLK for generating data from the shift register 124 is generated and phased to have a predetermined phase difference from the first phase signal Phase A. A reception control signal generator 108 generating a shift signal SRCLK for a shift command of the shift register 124 based on the delayed second phase signal Phase B, The reception control unit 12, A latch unit 122 for latching the first phase signal Phase A and the sensor driving signal IR_SIG; And The latch signal is sequentially input, but the latched signal is loaded using the load signal RCLK, the data is read from the rising edge of the second phase signal Phase B using the shift signal SRCLK, and the first phase signal ( Non-contact obstacle detection device for a cleaning robot comprising a; shift register 124 for n-shift at the falling edge of the phase A). The method of claim 1, wherein the sensor unit, a light emitting diode configured to output infrared rays for sequentially detecting obstacles using n-th sensor driving signals for n sensors; And And a light receiving transistor positioned such that a reception angle has a predetermined angle with respect to an emission angle of infrared rays output from the light emitting diodes. The method of claim 1, wherein the first phase signal (Phase A) is used to emit infrared light, the second phase signal (Phase B) is used to receive infrared light and the first phase signal (Phase A) Non-contact obstacle detection device for a cleaning robot, characterized in that the counting and indexing by the counter (102).

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