Summary of the invention
A kind of obstacle detector based on infrared modulated, including an infrared modulated detection module, the infrared modulated
Detection module includes structure qualification element, infrared transmitting tube and infrared receiving terminal, and infrared transmitting tube and infrared receiving terminal are in each other
At an angle is set on structure qualification element, and the transmitting visual angle of infrared transmitting tube and the reception visual angle of infrared receiving terminal intersect to form
One closed detection zone, the infrared receiving terminal come from the infrared hair for receiving barrier reflection in the detection zone
Penetrate the modulated signal of pipe.
Further, the center line of the infrared transmitting tube and the infrared receiving terminal forms a predetermined angle, so that
The detection zone is defined in the predetermined distance range immediately ahead of the structure qualification element.
Further, the predetermined distance range is set greater than 4 centimetres and less than 10 centimetre.
Further, emitting from the modulated signal of the infrared transmitting tube is the discontinuous pulses for being modulated into predeterminated frequency
String, the discontinuous pulses string are the carrier signal of predeterminated frequency and modulated signal phase based on infrared coding and obtain;
Wherein, the predeterminated frequency is to be determined by the infrared coding, and the infrared coding is the infrared receiving terminal institute
The Signal coding agreement that can be identified.
Further, the predeterminated frequency is set as 38KHz or 40KHz.
A kind of detection method based on the obstacle detector, the detection method include:
It is realized by several duty cycles to the transmitting signal of the infrared transmitting tube on the structure qualification element and described red
The control of the outer demodulated output signal for receiving head, then judges the knot according to the demodulated output signal of the infrared receiving terminal
Whether there are obstacles in detection zone defined by structure restriction element;
When there are following pulse sequences can determine whether the detection zone memory for the transmitting signal and the demodulated output signal
In barrier, wherein pulse sequence includes:
(1) between t0 moment and t1 moment, the infrared transmitting tube emits the successive pulse groups of one section of predeterminated frequency, correspondingly,
The infrared receiving terminal receives the successive pulse groups of the detection zone internal reflection, demodulated output low level;Its
In, the successive pulse groups are the high level pulse of the modulated signal based on infrared coding and the carrier signal of the predeterminated frequency
Mutually with obtain, the infrared coding is the Signal coding agreement that the infrared receiving terminal can identify;
(2) between t1 moment and t2 moment, there is not train of pulse in the transmitting signal of the infrared transmitting tube, which makees
For the free time interval for emitting signal, correspondingly, the infrared receiving terminal receives the described of the detection zone internal reflection
Emit signal, demodulated output high level;
(3) the t2 moment, into next duty cycle;
(4) working sequence of the period at t2 moment to t3 moment repeats step (1), the work of the period at t3 moment to t4 moment
Make timing and repeat step (2), then enters next but one duty cycle, such iteration, so that the infrared receiver at the t4 moment
Head persistently receives the brewed infrared signal from infrared transmitting tube transmitting of the detection zone internal reflection;
When above-mentioned pulse sequence is not present in the demodulated output signal of the infrared receiving terminal, obstacle is not present in the detection zone
Object.
Further, the predeterminated frequency be the frequency adaptation characteristic according to the infrared receiving terminal and modulate come, with
Eliminate environmental light intensity or the influence of other noise signals.
Further, the transmitting signal of the infrared transmitting tube is the modulated discontinuous pulses string that the predeterminated frequency is made,
The free time interval in the discontinuous pulses string is determined according to the fixation idling cycle of the carrier signal of the predeterminated frequency
's;
Wherein, the discontinuous pulses string is that the carrier wave of the modulated signal and driving infrared emission that are transferred to the infrared transmitting tube is believed
Number phase with obtain, what the numerical value of the fixed idling cycle was determined by the infrared coding.
Further, the output power of the infrared transmitting tube makes the infrared receiving terminal be completely received the inspection
Survey the transmitting signal that barrier is reflected in region.
A kind of robot, the robot are a kind of movable machine people, which is installed with one or more groups of described
Obstacle detector.
Compared with the existing technology, beneficial effects of the present invention: the present invention implements to connect by the infrared component using low cost
The modulated pulse signal of the barrier limited in response region a reflection is received to detect barrier, solves the barrier in limited area
Hinder analyte detection problem, the reflecting surface of black can be detected by way of modulated pulse signal, improve detection of obstacles
Sensitivity.
Specific embodiment
Specific embodiments of the present invention will be further explained with reference to the accompanying drawing:
In the description of invention, it is to be understood that term " center ", "front", "rear", "left", "right", " hard straight ", "horizontal",
The orientation or positional relationship of the instructions such as "top", "bottom", "inner", "outside" is to be based on the orientation or positional relationship shown in the drawings, and is only
For ease of description invent and simplify description, rather than indication or suggestion meaning device or element must have a particular orientation,
It is constructed and operated in a specific orientation, therefore should not be understood as the limitation to invention.
As shown in Figure 1, the present embodiment provides a kind of obstacle detector based on infrared modulated, including an infrared tune
Detection module processed, the infrared modulated detection module include structure qualification element 101, infrared transmitting tube 102 and infrared receiving terminal
110, structure qualification element 101 is used as load carrier, red for fixing and being isolated infrared transmitting tube 102 and infrared receiving terminal 110
Outer transmitting tube 102 and infrared receiving terminal 110 are set on structure qualification element 101 in angle of intersection, pass through structure qualification member
Part 101 converges to the optical path of infrared transmitting tube 102 and infrared receiving terminal 110 on region 109.Optical path 105 and optical path 103 surround
The transmitting angular field of view of infrared transmitting tube 102, optical path 105 and optical path 103 are crossed to form the angle of departure of infrared transmitting tube 102, and 104
Indicate the center line of infrared transmitting tube 102;Optical path 106 and optical path 107 surround the reception angular field of view of infrared receiving terminal 110, light
Road 106 and optical path 107 are crossed to form the acceptance angle of infrared receiving terminal 110, and 108 indicate the center line of infrared receiving terminal 110.Region
The closed detection zone that the transmitting visual angle of 109 expression infrared transmitting tubes and the reception visual angle of infrared receiving terminal intersect to form
The closed irregular figure that domain, i.e. optical path 105, optical path 103, optical path 106 and optical path 107 surround, the detection zone position
In the light emitting region of infrared transmitting tube 102 intersect with the range of receiving of infrared receiving terminal 110 it is common within sweep of the eye, the inspection
The barrier reflection surveyed in region is stronger, and the light intensity that infrared receiving terminal 110 receives is also stronger.
In the detection zone 109 formed by the restriction effect of structure qualification element 101,110 energy of infrared receiving terminal
It enough receives barrier in detection zone 109 and reflects the IR modulated signals from the infrared transmitting tube 102;Wherein barrier is anti-
The signal penetrated is the modulated signal emitted from the infrared transmitting tube, that is, be transferred to the modulated signal of the infrared transmitting tube with
The signal that the carrier pulse of driving infrared emission is multiplied.
Preferably, the center line 108 of the center line 104 of the infrared transmitting tube 102 and the infrared receiving terminal 110 formation
One predetermined angle, so that the detection zone 109 is defined in the predetermined distance range in 101 front of structure qualification element
Interior, i.e. the minimum range in 101 front of detection zone 109 and the structure qualification element is h1, maximum distance h2 in Fig. 1.
Specifically, h1 is set as 4 centimetres, and h2 is set as 10 centimetres.The predetermined distance range is set greater than 4 centimetres and less than 10 li
Rice.
Preferably, the output power of the infrared transmitting tube is constant, and its watt level meets the infrared receiving terminal
Receive and demodulate the intensity requirement of the predetermined distance range internal reflection signal.Obstacle distance institute in the detection zone 109
State that infrared receiving terminal 110 is closer, the reception signal of the infrared receiving terminal 110 is stronger, when the two distance is less than anticollision distance
When can cause safety problem;Infrared receiving terminal 110 described in obstacle distance is remoter in the detection zone 109 (is greater than anticollision
Distance), the reception signal of the infrared receiving terminal 110 is weaker, when the center line 104 of the infrared transmitting tube 102 and described red
When the outer center line 108 for receiving head 110 is almost without intersection point, the reception signal of the infrared receiving terminal 110 can not be demodulated.
Therefore need to limit a detection zone 109 in the predetermined distance range, then adjust the defeated of the infrared transmitting tube 102
Power carries out detection of obstacles out, so that barrier is reflected back the signal for being suitable for demodulating intensity to institute in detection zone 109
State infrared receiving terminal 110.The infrared transmitting tube 102 according to during actually detected barrier the predetermined distance range it is big
It is small, the output power of a stability number is set to meet and limit the reception of the infrared receiving terminal 110 barrier reflection in range
The intensity requirement of signal excludes the influence of other light pulses, improves detection effect, realizes low-power consumption detection.
Preferably, emitting from the signal of the infrared transmitting tube 102 is the discontinuous pulses string for being modulated into predeterminated frequency, should
Discontinuous pulses string is the carrier signal of predeterminated frequency and modulated signal phase based on infrared coding and obtain, wherein predeterminated frequency
It is to be determined by infrared coding, and infrared coding is the Signal coding agreement that the infrared receiving terminal 110 can identify.It is described pre-
If frequency is set as 38KHz or 40KHz, implement the infrared coding that the infrared receiving terminal 110 can identify to meet the present invention
Agreement.The conventional impulse modulation mode of the transmitting terminal use being connected with the infrared external reflection pipe 102 (such as pulse width modulation
(PWM), the methods of pulse position modulation (PPM)), binary digital signal is modulated into the discontinuous pulses string of predeterminated frequency, and
Driving infrared transmitting tube 102 is sent in the form of light pulse, i.e., carries useful information by the carrier signal of predeterminated frequency
Modulated signal be sent to recipient.Wherein, modulated signal interval is sent, and first sends one section of continuous impulse with predeterminated frequency
Sequence enters back into idle state, then sends one section of continuous impulse sequence with predeterminated frequency again, enters back into idle state,
It is so alternate to send;
As one embodiment, the modulated signal is a kind of binary signal, as shown in figure 3, the logic in binary signal
The pulse width of ' 1 ' low and high level signal is equal to 0.26ms, the arteries and veins of the low level signal of the logic ' 0 ' in binary signal
Width is rushed equal to 0.52ms, the pulse width of high level signal is equal to 0.26ms.It should be noted that different infrared codings
In, the corresponding duty ratio of logical zero and logical one is different in binary signal, i.e., the pulse of corresponding low and high level signal is wide
The ratio of degree is different.And in present invention implementation, various common infrared remote coding agreements are suitable for the modulated signal.
Further, the light arteries and veins received is converted into electric signal by the infrared receiving terminal, using amplification, filtering etc.
Demodulator circuit is given after reason to be demodulated, and is exported after being reduced to binary digital signal.When the infrared receiving terminal receives tune
When signal processed, a low level is exported, a high level is otherwise exported, because of the infrared receiving terminal demodulated output signal and institute
The original transmitted signal for stating infrared transmitting tube is opposite.
Based on the obstacle detector, present invention implementation provides a kind of detection method, which includes:
It is realized by several duty cycles to the transmitting signal of the infrared transmitting tube 102 on the structure qualification element and described
The control of the demodulated output signal of infrared receiving terminal 110, then according to the reception signal of the infrared receiving terminal 110 to judge
State in detection zone 109 defined by structure qualification element 101 that whether there are obstacles;
Specifically, it in order to realize the detection function of modulated signal, needs to do corresponding timing control to the infrared transmitting tube 102
System, the demodulated output signal by detecting the infrared receiving terminal 110 judge defined by the structure qualification element to realize
Whether there are obstacles in detection zone 109.As shown in Fig. 2, figure middle and upper part is divided into the brewed of the infrared transmitting tube 102
Emit signal, figure middle-lower part is the demodulated output signal of the infrared receiving terminal 110.When the transmitting signal and the demodulation
There are following pulse sequences can determine whether in the detection zone 109 that wherein pulse sequence includes: there are barrier for output signal
(1) between t0 moment and t1 moment, the infrared transmitting tube 102 emits the successive pulse groups of one section of predeterminated frequency, accordingly
Ground, the infrared receiving terminal 110 receive the successive pulse groups of 109 internal reflection of detection zone, demodulated output
Low level;Wherein, the successive pulse groups are the high level pulse and the predeterminated frequency of the modulated signal based on infrared coding
Carrier signal phase with obtain, the infrared coding is the Signal coding agreement that the infrared receiving terminal can identify;
(2) between t1 moment and t2 moment, there is not train of pulse in the transmitting signal of the infrared transmitting tube 102, the time
Duan Zuowei emits the free time interval of signal, and correspondingly, the infrared receiving terminal 110 receives in the detection zone 109
The transmitting signal of reflection, demodulated output high level;
(3) the t2 moment, into next duty cycle;
(4) working sequence of the period at t2 moment to t3 moment repeats step (1), the work of the period at t3 moment to t4 moment
Make timing and repeat step (2), then enters next but one duty cycle, such iteration, so that the infrared receiver at the t4 moment
First 110 persistently receive the brewed infrared letter from the infrared transmitting tube 102 transmitting of 109 internal reflection of detection zone
Number;The 102 repeated work timing (1) to (4) of infrared transmitting tube, constantly transmitting modulated signal, and barrier is in described
Brewed infrared signal can be reflected in detection zone 109, and the infrared receiving terminal 110 is allowed persistently to receive reflection letter
Number.
Wherein the successive pulse groups of predeterminated frequency are the binary signal for loading the coding of carrier signal, and described infrared are connect
The reflection signal that receipts head 110 receives is that a part of the entire barrier or barrier in the detection zone 109 is anti-
Penetrate face.
When above-mentioned pulse sequence is not present in the demodulated output signal of the infrared receiving terminal 110, the detection zone 109 is not
There are barriers.
Preferably, the predeterminated frequency be modulated according to the frequency adaptation characteristic of the infrared receiving terminal 110 come, with
Meet the requirement of common infrared coding agreement.Specifically, infrared light can be made with specific frequency scintillation by modulation, it is described
Infrared receiving terminal 110 can be adapted to this frequency, other noise signals are all ignored.The different of carrier wave are modulated according to transmitting terminal to select
The reception head of corresponding frequency, demodulation frequency.In the embodiment of the present invention, the predeterminated frequency is set as 38KHz or 40KHz.
Preferably, the transmitting signal of the infrared transmitting tube 102 is the modulated discontinuous pulses string that the predeterminated frequency is made,
The free time interval in the discontinuous pulses string is according to the fixation idling cycle between the carrier signal of the predeterminated frequency
Determining, the modulated signal is the encoded signal based on infrared coding, and the numerical value of the fixed idling cycle is also by described red
The related protocol of outer coding determines.It is separated between the carrier pulse using the fixed idling cycle, to indicate logic
" 0 ", and the discontinuous pulses string is the load for being transferred to the modulated signal and driving infrared emission of the infrared transmitting tube 102
Wave signal phase with obtain.
As one embodiment of the present invention, infrared signal is modulated with pulse width modulation (PWM), pulse position tune
The methods of (PPM) is made, so that carrier frequency is adjustable.Pulsewidth modulation is used in the present embodiment.Binary modulation is by master control core
Piece is completed, it is modulated into the binary signal after coding the discontinuous pulses string that frequency is 38KHz, this interruption train of pulse is to use
In the modulated signal that the infrared transmitting tube 102 is sent.As shown in figure 4, waveform A is the coding waveforms of binary signal, wave
Shape B be frequency be the 38KHz(period be about 26us) successive pulse groups (being equivalent to carrier signal), the coding wave of binary signal
The pulse width of the low and high level of logical one is equivalent to the time width of 10 pulses in successive pulse groups B in shape A;And
The low level pulse width of logical zero is equivalent to the time width of 20 pulses in successive pulse groups B, the pulse of high level
Width is equivalent to the time width of 10 pulses in successive pulse groups B.Waveform C be it is modulated after discontinuous pulses string, be
Transmitting signal for the signal of transmission, corresponding to Fig. 2.
As shown in figure 4, binary data pending is 101, when there are when barrier, then in the detection zone 109
The modulated signal that the infrared transmitting tube 102 is sent is reflected to the infrared receiving terminal 110, the solution of corresponding binary signal
The signal (the waveform D in Fig. 4) received by the infrared receiving terminal 110 is adjusted through inter-process and demodulates recovery, exports Fig. 4
In waveform E (waveform A's negates in exactly Fig. 4), i.e., the demodulation of the described infrared receiving terminal can be regarded as: in input pulse string
When export low level, otherwise export high level.Binary decoding is completed by main control chip, it sends infrared receiving terminal
Binary coding waveform is reduced into the binary data that the infrared transmitting tube is sent by decoding.Such as Fig. 4, waveform E is decoded
It is reduced into data information 101, may determine that show that there are barriers in the detection zone 109 at this time.
Preferably, the infrared transmitting tube 102 is in the detection zone 109 at a distance from the structure qualification element 101
The power of output constant intensity in range, so that the infrared receiving terminal 110 can only receive obstacle in the detection zone 109
The transmitting signal of object reflection;Wherein, the detection zone 109 and the distance range of the structure qualification element 101 are big
In 4 centimetres less than 10 centimetres.The minimum range of detection zone 109 as shown in Figure 1 and 101 front of structure qualification element
For h1, maximum distance h2.Specifically, h1 is set as 3 centimetres, and h2 is set as 8 centimetres.The infrared transmitting tube 102 is according to reality
The size of the predetermined distance range during barrier is detected on border, sets the output power of a stability number to meet and limit
The infrared receiving terminal 110 receives the intensity requirement of barrier reflection signal in range.
During atual detection, entire barrier is located at the 101 front detection zone of structure qualification element
Region except 109, as shown in Figure 1, being divided into two kinds of embodiments.Embodiment one, when barrier is located at optical path 105 and optical path 103
When surrounding the region #1 in the light emitting region of infrared transmitting tube 102 except the detection zone 109, region #1 is not in optical path 106
Surrounded in the reception angular field of view of infrared receiving terminal 110 with optical path 107, due to the infrared transmitting tube 102 output power and
The limitation of the detection zone, the infrared receiving terminal 110 almost do not receive the reflection signal of the barrier in the #1 of region or connect
Extremely weak signal is received so that it cannot demodulated output signal;