KR101280563B1 - Transmitting /Receiving Integrated Chip for Mobile robot and Mobile robot using the same - Google Patents

Abstract

The present invention provides a highly integrated chip integrated with a transmission and reception function required for the operation of the mobile robot, and a mobile robot having the highly integrated chip. The present invention provides a main oscillator, a trigger oscillator, a time-stable monostable multivibrator connected to the trigger generator, a buster gate that delivers the outputs of the vibrator and the main oscillator, and outputs the output of the buster gator to a transmission sensor. A transmitter including an output drive circuit for transmitting; A preamplifier connected to a receiving sensor, a main amplifier connected to the preamplifier, a variable gain amplifier connected to the main amplifier, a detection circuit connected to the variable gain amplifier, a waveform shaping circuit connected to the detection circuit, and the waveform shaping A receiver having a distance pulse generation circuit connected to the circuit; And a counter for counting a waveform of the main oscillator and providing a signal for controlling the variable gain of the variable gain amplifier.

Description

Transmitting / Receiving Integrated Chip for Mobile robot and Mobile robot using the same}

The present invention relates to a transmission and reception integrated chip for a mobile robot and a mobile robot having the same.

Robots have been developed for industrial use and as part of factory automation, or have been used to collect or collect information on behalf of humans in extreme environments that humans cannot tolerate. This field of robotics has been developed in recent years as it is used in the state-of-the-art space development industry, and until recently, human-friendly home robots have been developed. A representative example of such a human-friendly home robot is a cleaning robot. A cleaning robot, a mobile robot, is a device that inhales dust or foreign substances while driving itself in a certain cleaning area such as a house or an office.

The mobile robot must have a circuit for receiving an input signal and outputting the signal. The transmission and reception circuit provided in the mobile robot is generally implemented using an analog circuit. In case of configuring the transmitting / receiving circuit of the ultrasonic sensor with analog, the circuit size is large, power consumption is large, and the characteristics are also difficult to change.

The present invention provides a highly integrated chip integrated with a transmission and reception function required for the operation of the mobile robot, and a mobile robot having the highly integrated chip.

The present invention relates to a main oscillator, a trigger oscillator, a time-stable monostable multivibrator connected to the trigger generator, a buster gate for delivering the sum of the outputs of the vibrator and the main oscillator, and the output of the buster gator as a transmission sensor. A transmitter including an output drive circuit for transmitting; A preamplifier connected to a receiving sensor, a main amplifier connected to the preamplifier, a variable gain amplifier connected to the main amplifier, a detection circuit connected to the variable gain amplifier, a waveform shaping circuit connected to the detection circuit, and the waveform shaping A receiver having a distance pulse generation circuit connected to the circuit; And a counter for counting a waveform of the main oscillator and providing a signal for controlling the variable gain of the variable gain amplifier.

The present invention provides an anisotropic ultrasonic sensor attached to the mobile robot for transmitting an ultrasonic signal for detecting the obstacle; A receiving anisotropic ultrasonic sensor for receiving the received ultrasonic signal in response to the ultrasonic signal transmitted from the transmitting anisotropic ultrasonic sensor; A transmit / receive chip for controlling the transmitting ultrasonic sensor to transmit to the ultrasonic sensor and correspondingly providing an output waveform corresponding to the received ultrasonic signal; And a microprocessor embedded in a mobile robot to calculate the arrival time of the ultrasonic waves using the signal received from the transmission / reception chip, and to calculate the position of the current mobile robot using the arrival time of the ultrasonic waves. And a transmitter including a trigger oscillator and a buster gate for adding the outputs of the main oscillator and the main oscillator to the transmitting anisotropic ultrasonic sensor. A receiver comprising a main amplifier connected to the receiving anisotropic ultrasonic sensor, a variable gain amplifier connected to the main amplifier, and a distance pulse generation circuit connected to the variable gain amplifier to generate the output waveform; And a counter for counting the waveform of the main oscillator and providing a signal for controlling the variable gain of the variable gain amplifier.

By using the digital transmission / reception chip according to the present invention, disadvantages in the transmission / reception function implemented by the existing analog circuit are overcome. The circuit size can be reduced, and the low-voltage low-power design can reduce power consumption. In addition, since the digital transmit / receive chip according to the present invention includes a variable gain amplifier, it is possible to detect an object with high sensitivity. In addition, it is possible to implement various transmission modes (free run mode, external trigger mode) of the transmission and reception digital highly integrated chip according to the present invention.

In addition, the mobile robot having a digital transmit / receive chip according to the present invention is capable of detecting obstacles over the entire range using a small number of ultrasonic sensors using anisotropic ultrasonic sensors, and uses a high transmit / receive chip for long distances. Obstacles in the can be easily recognized, and if the obstacle is recognized can be easily avoided.

As a result, the present invention provides a high transmit / receive integrated chip capable of facilitating the installation of the anisotropic ultrasonic sensor in the mobile robot and reducing the battery consumption of the mobile robot while having a small size and low power consumption.

Figure 1 is a schematic diagram showing the obstacle recognition range while driving the mobile robot when using a universal ultrasonic sensor.
Figure 2 is a schematic diagram showing the obstacle recognition range of the mobile robot when the mobile robot according to the present invention using an anisotropic ultrasonic sensor.
Figure 3 is a block diagram showing the configuration of a mobile robot according to an embodiment of the present invention
Figure 4 is an internal block diagram showing a highly integrated transceiver chip of the mobile robot according to an embodiment of the present invention.
5 is a schematic diagram showing how the mobile robot of FIG. 3 recognizes an obstacle.
<Description of the symbols for the main parts of the drawings>
11 main oscillators 12 Multi Vibrator
13 Trigger Oscillators 14 Output Drive Circuits
15 Burst Gate 16 Pre Amp
17 Main Amp 18 Variable Gain Amplifier
19 Detection Circuit 20 Mobile Robot
21 Microprocessor 22 Receive Gain Amplifier
23 Transmitting voltage amplifier 24 Anisotropic ultrasonic sensor for reception 1
25 Anisotropic ultrasonic sensor for reception 2 26 Anisotropic ultrasonic sensor for transmission
27 Drive motor 28 Motor drive circuit
30 blind spots
31 Obstacle Recognition Range of Reception Anisotropic Ultrasonic Sensor 1
32 Obstacle Recognition Range of Receiving Anisotropic Ultrasonic Sensor 1,2
33 Obstacle recognition range of the anisotropic ultrasonic sensor 2 for reception
34 obstacles

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, in order to facilitate a person skilled in the art to easily carry out the technical idea of the present invention. do.

The present invention relates to a mobile robot having a high transmit / receive integrated chip capable of more easily avoiding obstacles while the mobile robot is driving. In addition, the mobile robot according to the present embodiment uses an anisotropic sensor.

Figure 1 is a schematic diagram showing the obstacle recognition range while driving the mobile robot when using a universal ultrasonic sensor.

As shown in FIG. 1, when the universal ultrasonic sensor is used, the front radiation angle of the universal ultrasonic sensor is only 60 degrees, and when installed in the mobile robot in a small amount, the obstacle recognition range is small when the obstacle is detected, thereby avoiding impulse avoidance. Poor ability Here, the obstacle recognition range 31 of the receiving anisotropic ultrasonic sensor 1 and the obstacle recognition range 33 of the receiving anisotropic ultrasonic sensor 2 are narrow, so that the blind spot 30 may be wide.

In order to overcome this problem, the present invention proposes a mobile robot having an anisotropic ultrasonic sensor limited to about 30 to 60 degrees so as to have an optical orientation of about 180 degrees in the horizontal direction and not to receive unnecessary signals in the vertical direction.

Figure 2 is a schematic diagram showing the obstacle recognition range of the mobile robot when the mobile robot according to the present invention using an anisotropic ultrasonic sensor.

As shown, when the mobile robot according to the present invention includes the anisotropic ultrasonic sensor, the anisotropic ultrasonic sensor has an optical recognition characteristic of about 180 degrees in the horizontal direction, so that the anisotropic ultrasonic sensor can receive anisotropy. The obstacle recognizable range 31 of the ultrasonic sensor 1, the common obstacle recognizable range 32 of the receiving anisotropic ultrasonic sensors 1 and 2, and the obstacle recognizable range 33 of the receiving anisotropic ultrasonic sensor 2 become very wide. . Therefore, the impulse avoidance ability is improved.

Figure 3 is a block diagram showing the configuration of a mobile robot according to an embodiment of the present invention.

As shown in Figure 3, the mobile robot according to the embodiment of the present invention is a microprocessor 21, anisotropic ultrasonic sensor 1 (26) for transmission, anisotropic ultrasonic sensor 1 (24) for reception, anisotropic ultrasonic sensor 2 for reception (2). 25, a transmission gain amplifier 23, a reception gain amplifier 22, a reception gain amplifier 20, a motor drive circuit 28, and a motor 27 are provided.

The anisotropic ultrasonic sensor 1 26 for transmission is a sensor for receiving an ultrasonic signal, and the anisotropic ultrasonic sensor 1 24 for receiving and the anisotropic ultrasonic sensor 2 25 for receiving are sensors for receiving an ultrasonic signal. The transmission gain amplifier 23, the reception gain amplifier 22, and the reception gain amplifier 20 are each for amplifying a signal used in a corresponding sensor and converting the signal into a signal that can be recognized by the microprocessor. The motor driving circuit 28 is for driving the motor 27, and the microprocessor 21 is for controlling the operation of each sensor, the amplifier and the motor driving circuit.

Figure 4 is an internal block diagram showing a highly integrated transmit and receive chip equipped with a mobile robot according to an embodiment of the present invention.

The transmit / receive chip according to the present embodiment outputs an ultrasonic signal, and receives a signal in response to the output ultrasonic signal, and informs the process of how long the received signal is input.

The highly integrated transceiver chip provided in the mobile robot according to the present embodiment is divided into a transmitter and a receiver.

The transmitting unit includes a main oscillator 11, a trigger oscillator 13, a time sustained monostable multi-vibrator 12, a burst gate 15 and an output drive circuit 14. The output drive circuit 14 is connected with a sensor for transmission.

The main oscillator 11 of the transmitter has a specification that its performance can be varied in the range of 20 to 100 kHz, and its frequency range can be changed depending on the purpose. The main generator 11 serves to generate an ultrasonic signal.

Trigger oscillator 13 is variable in the range of 5 ~ 100Hz to adjust the operating speed of the ultrasonic sensor, it can be changed according to the use environment. The dominant sensor operates in the 40kHz band, but as a special use, it is required to be able to cope with low frequency far distance (20kHz) to high frequency precision measurement. The operating frequency of the main oscillator 11 may be varied by R and C values connected to external terminals.

 Trigger oscillator 13 is variable in the range of 5 ~ 100Hz to adjust the period of the burst signal (Burst). The sensor provided in the mobile robot according to the present embodiment may have an operating range of about 20 to 30 Hz, but when used for other industrial purposes, it may be operated by external R and C so as to select a different period according to its surrounding environment. You can set the frequency.

The time-stable monostable multivibrator 12 is an important part of determining the duration of the buster signal. It is related to the strength of the ultrasonic sound pressure or the accuracy of the distance measurement. Therefore, an appropriate range should be set. to be. This value can also be determined by external R and C time constants.

The three oscillator elements (11, 12, 13) described so far are useful when used alone by utilizing functions built into the transceiver chip itself, but do not use the functions when generating and applying signals from an external system such as a processor. It is arranged in a separate block and can be used as an external pin connection only when necessary. Therefore, the transmission / reception chip according to the present embodiment has a structure corresponding to all of various specifications and uses. Since there is an external connection step, it is possible to connect and use an external connection terminal directly, or to provide a desired signal through the external connection terminal.

The buster gate 15 is a gate that implements a simple logic logical product, and can be controlled by an external program or by using the built-in time-stable monostable multivibrator 12 output for controlling the main oscillation waveform.

The buster gate 15 eventually serves to sum and output the signal output from the main oscillator 11 and the signal provided from the time-stable monostable multivibrator 12. By passing through the buster gate 15, the buster Waveforms are generated whose output is so weak that the output driver circuit 14 augments it.

The output driver circuit 14 changes the level of the output signal according to an externally provided voltage (5 to 40V DC). The final output is capable of driving up to 20mA of current and can specifically boost the supply voltage in this area (up to 40Vdc), resulting in a significant negative pressure output. In addition, the built-in output circuit can achieve a low impedance and damping effect using a push-pull (PP) method, and a NOP device can be used to avoid a dangerous short circuit in the PP circuit.

Since all circuits provided in the highly integrated transceiver chip according to the present embodiment are designed based on a power supply voltage of 5V, the same power source as a general digital circuit can be used. In addition, depending on the application, a 12V power supply can be used, or a 24V power supply can be used for industrial purposes.

The receiver has three stages of main amplification, pre-amp 16, main amplifier 17, variable gain amplifier 18, detection circuit 19, waveform shaping circuit 20, distance pulse generation circuit. (21) and the like. The variable gain amplifier 18 is also connected to the counter 15.

The receiver has three stages of amplification stages 16, 17 and 18. The first preamplifier 16 has an amplification degree of up to about 30 dB, and changes in gain or frequency characteristics by R and C connected to the outside. You can do that and configure your filter. That is, the external connection terminal can be directly connected or a filter can be connected. In the preamplifier 16, the amplification degree can be set to about 20 dB, and the gain distribution can be adjusted to obtain a wider adjustment range. The preamplifier is also a completely independent circuit that can be implemented to be selectively used as needed.

The main amplifier 17 is fixed at about 14 dB, so no external adjustment is necessary, and the subsequent variable gain amplifier (VGA) 18 can have a gain of up to 26 dB. Therefore, the total maximum gain of the receiver is about 70 dB (3,000 times). It is very sensitive compared to the gain of 900 ~ 1,000 times the gain of general ultrasonic receiver module.

Among the blocks included in the highly integrated transceiver chip according to the present exemplary embodiment, the variable gain amplifier 18 may be referred to as a variable gain amplifier over time. The gain and gain may be gradually increased over time. The importance can be explained as follows. In order to detect an object by extending the communication distance to a long distance, the reception sensitivity is generally high. However, since the sound pressure is strong in the near object, the receiver saturates quickly.

The saturated signal is ambiguous in timing, making accurate measurement difficult, and subsequent fine signals are masked to become insensitive. Therefore, in this state, the gain must be lowered to receive a clear signal, but the far-field signal is weakened and becomes undetectable. Therefore, it is necessary to adjust the gain according to the distance of the object to be detected. It is a device to make the function automatic.

This may be implemented by adjusting the gain of the variable gain controller 18 according to the control signal provided from the counter. The counter is counted by a predetermined number and then reset. The counted signal is provided to the variable gain controller 18 so that the variable gain controller 18 can automatically vary the gain according to the signal input from the counter. .

On the basis of the fact that the time difference from the buster transmission is proportional to the distance of the object, it gradually increases from the minimum sensitivity at the beginning of the transmission, and the same operation is repeated at the same time as the reset. This functional circuit is very difficult to implement as a general purpose component. Of course, in the past, there have been cases of using an op amp having such a function as a complex function in addition to a time function generator, but now, such an analog device cannot realize the advantages of digital.

The method of changing gain by an external electrical signal was to insert a semiconductor device or a material having a characteristic of performing square or square root operation in the previous analog method. In recent years, all of them are digitally converted to D / A conversion. A method of converting it into a change in resistance value and inserting it into a feedback circuit is used. Program control is easy and specification can be changed.

The transmit / receive chip according to the present embodiment performs digitization by a counter at an initial burst out point, and sequentially increases and decreases gain by sequentially opening and closing the feedback resistor array according to the change of this value. That's the way.

It is an operation similar to controlling the detent volume by the level control unit of a special acoustic device, which is characterized by automatic operation. The counter clock used here uses the main oscillator (20-100kHz) output signal. In this principle, the lower the frequency, the slower the speed of gain increase, and the increasing slope gradually increases in proportion to the frequency. In other words, low frequencies have less damping in the air and reach a considerable distance, so a gentle increase is realistic, while high frequencies have a rapid damping (shorter reach), requiring fast gain compensation. This allows the high frequency sensor to extend the measurement distance to some extent.

The detection circuit 19 uses an excellent circuit having a very low signal loss as a full-wave rectification method using a differential amplifier. In this method, the signal is completely transmitted to the zero point by opening and closing the switch in synchronization with the ultrasonic reception signal. The detected waveform is a shape of a mountain from which only the envelope of the received signal is extracted and cannot be directly input to a digital circuit. Therefore, the waveform is transformed into a completely square wave through a comparator of zero crossing concept. do. In practice, set the threshold at a position slightly above the zero potential to determine the appropriate point to ignore fine noise or ripple.

This threshold potential is implemented as an externally adjustable structure. The shaped square wave comes out as an external output terminal, but part is applied to the distance pulse generator. This circuit 21 is a latch function that converts the time difference between the generation of the transmission buster and the reception of the received signal into the duration of the pulse width. Therefore, when the distance is very long or there is no reception input, a continuous high level signal (5V) is output, and as the distance is closer, it changes to an impulse form. This signal can be analog-integrated as it is, converted into a DC voltage, directly read by a meter, or used as a gate signal of a clock pulse to convert it into a distance value proportional to a counter value.

There are three outputs in the receiver, one of the analog received amplified wave (analog out) just before the detection, the received pulse wave (real time pulse) after the detection and waveform shaping, and the last processed time pulse. As it is useful according to external application, it can be used as needed through each terminal.

Effect of Variable Gain Amplifier (VGA)

If the received signal is observed while moving the same object by distance without the variable gain amplifier 18 (or released), as the distance increases, the signal weakens and accordingly, the shaped square wave gradually decreases and disappears. Comes out. On the other hand, it can be seen that at close range, the signal is too much saturated and the square wave is too large. It can be understood that if the variable gain amplifier 18 operates in its function, the signal at a short distance is smaller than before and does not change much over a distance. If you shape it as a square wave, you will get a waveform of a generally uniform shape.

FIG. 5 is a schematic diagram illustrating a method for recognizing an obstacle by the mobile robot of FIG. 3.

First, the mobile robot according to the present embodiment calculates the distance to the obstacle by the following equation.

T: time of receiving ultrasonic signal

t: time when trigger signal is transmitted

The microprocessor 21 of the mobile robot 20 according to the present embodiment generates an operation signal of the anisotropic ultrasonic sensor 26 for transmission to detect an obstacle, and transmits the anisotropic ultrasonic sensor 26 via the transmission voltage amplifier 23. ). The microprocessor 21 of the mobile robot 20 is reflected by an obstacle on the basis of the time point transmitted by the transmitting anisotropic ultrasonic sensor 26 as shown in FIG. 5 to the receiving anisotropic ultrasonic sensors 1, 2 (24, 25). The distances d1 and d2 are calculated by measuring the received time of arrival. When the distance between the obstacles d1 and d2 is compared, the mobile robot turns to the right when d2 is larger than d1, and the mobile robot turns to the left when d1 is larger than d2 to avoid obstacles ahead.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the present invention. I will understand. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, as well as the appended claims.

Claims (6)

A main oscillator, a trigger oscillator, a time sustained monostable multivibrator connected to the trigger generator, a buster gate that delivers the outputs of the vibrator and the main oscillator, and an output that transmits the output of the buster gator to a transmission sensor. A transmitter including a drive circuit;
A preamplifier connected to a receiving sensor, a main amplifier connected to the preamplifier, a variable gain amplifier connected to the main amplifier, a detection circuit connected to the variable gain amplifier, a waveform shaping circuit connected to the detection circuit, and the waveform shaping. A receiver having a distance pulse generation circuit connected to the circuit; And
A counter for counting the waveform of the main oscillator to provide a signal for controlling the variable gain of the variable gain amplifier
Transmitting and receiving chip for a mobile robot comprising a.
The method of claim 1,
Transmitting and receiving chip for the mobile robot, characterized in that the transmitting sensor and the receiving sensor is an ultrasonic sensor.
The method of claim 1,
Transmitter / receiver chip for mobile robots whose main oscillator operates in the range of 20 ~ 100 kHz and the trigger oscillator operates in the range of 5 ~ 100Hz.
A transmission anisotropic ultrasonic sensor attached to the mobile robot and transmitting an ultrasonic signal for detecting an obstacle;
A receiving anisotropic ultrasonic sensor for receiving the received ultrasonic signal in response to the ultrasonic signal transmitted from the transmitting anisotropic ultrasonic sensor;
A transmit / receive chip for controlling the transmitting ultrasonic sensor to transmit to the ultrasonic sensor and correspondingly providing an output waveform corresponding to the received ultrasonic signal; And
A microprocessor which is embedded in a mobile robot and calculates the arrival time of the ultrasonic wave using the signal received from the transmission / reception chip, and calculates the position of the current mobile robot using the arrival time of the ultrasonic wave,
The transceiver chip is
A transmitter including a main oscillator, a trigger oscillator, and a buster gate for adding the outputs of the main oscillator and the main oscillator to the transmitting anisotropic ultrasonic sensor;
A receiver comprising a main amplifier connected to the receiving anisotropic ultrasonic sensor, a variable gain amplifier connected to the main amplifier, and a distance pulse generation circuit connected to the variable gain amplifier to generate the output waveform; And
A counter for counting the waveform of the main oscillator to provide a signal for controlling the variable gain of the variable gain amplifier
Mobile robot comprising a.
delete 5. The method of claim 4,
The main oscillator operates in the range of 20 ~ 100 kHz, the trigger oscillator operates in the range of 5 ~ 100Hz.

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