CN202230201U

CN202230201U - Closed loop laser scanning range-finding device

Info

Publication number: CN202230201U
Application number: CN2011203501263U
Authority: CN
Inventors: 黄文恺; 陈虹; 唐连章
Original assignee: Guangzhou University
Current assignee: Guangzhou University
Priority date: 2011-09-17
Filing date: 2011-09-17
Publication date: 2012-05-23
Anticipated expiration: 2021-09-17

Abstract

The present utility model relates to a close range laser range-finding device, specifically to a closed loop laser scanning range-finding device. The device is composed of an optical system, a control unit and a steering motor, and the optical system is formed by arranging an annular focusing lens, a laser transmitting tube and a laser receiver tube successively. The device is characterized in the control unit, a main controller which is formed by a one-chip microcomputer is a core, and a laser signal generator, a laser signal converter and a steering motor driving circuit are peripheral devices. When in work, the laser signal converter is used for converting received object reflection electric signals into high-low level and outputting to the one-chip microcomputer, and turning off the laser signal generator, when reflected laser can not be received by the laser receiver tube, then the laser signal converter is used for outputting opposite signals and opening the laser signal generator, and the one-chip microcomputer is used for calculating frequency of on/off of the laser signal generator, and converting the frequency into the distance of a measured object of the direction.

Description

A kind of closed loop laser scanning and ranging device

Technical field

The utility model relates to laser ranging field, particularly relates to closely laser ranging system.

Background technology

The laser scanning and ranging device is also referred to as laser radar, through mechanical rotary device; The rotation of drive laser sensor; Thereby being implemented in the range sweep of a two dimensional surface, can drawing the distance based on measured object on the different directions on this plane, is that the application for a patent for invention of CN501153795A discloses a kind of laser scanner like publication number; This scanner not only can be realized the range sweep of two dimensional surface, and can on both direction, come to an agreement measurement range.But the optical system of the described scheme of foregoing invention patented claim is very complicated, and the height of its cost is foreseeable.Publication number is that the application for a patent for invention of CN1779486A discloses a kind of laser ranging system; The optical system of this device is set gradually by ring-type condenser lens, LASER Discharge Tube and laser pick-off pipe to be formed, and has advantage simple in structure, that volume is little and with low cost.

But above-mentioned two applications for a patent for invention are distance-finding method openly both, does not also disclose concrete control circuit, will be that the disclosed technical scheme of application for a patent for invention of CN1779486A realizes that precision ranging remains in certain technical difficulty according to publication number obviously.Existing laser distance measurement method mainly contains interferometric method, impulse method, phase method etc.But wherein, impulse method needs the counter of ultraspeed, realize that difficulty is high, and closely distance accuracy is difficult to ensure, cost is expensive; Phase method and interferometric method precision on closely finding range is very high, but complex structure.Therefore, design the simple control circuit with low cost of a kind of circuit, measure to realize the high speed wide-angle, significant.

Summary of the invention

In view of there is above-mentioned deficiency in prior art; The utility model technical matters to be solved is; A kind of improved laser scanning and ranging device is provided, and the control circuit of this device can satisfy high speed wide-angle Testing requirement, and has advantage simple in structure, with low cost.

The technical scheme that the utility model addresses the above problem is following:

A kind of closed loop laser scanning and ranging device, this device is made up of optical system, control module and steer motor.Wherein said optical system is set gradually by ring-type condenser lens, LASER Discharge Tube and laser pick-off pipe to be formed; The reception optical axis of the laser pick-off pipe in the emission optical axis of described LASER Discharge Tube and the described laser pick-off unit is located along the same line, and the laser pick-off pipe is positioned on the focus of the ring-type condenser lens behind the LASER Discharge Tube; It is characterized in that,

The master controller that described control module constitutes with the ARM9 series monolithic is that the peripheral laser signal maker of core configuration, laser signal converter and steer motor driving circuit are formed; Wherein,

Described laser signal maker is the laser drive circuit of high-rate laser chip for driving and peripheral circuit formation thereof, and its output terminal is connected with described LASER Discharge Tube; Described laser signal converter is the shaping amplification circuit that high speed operation amplifier, reverser, d type flip flop connect and compose successively; Its high speed operation amplifier in-phase input end be connected with described laser pick-off pipe; The Q output terminal of d type flip flop is connected with the I/O mouth of said single-chip microcomputer, and the Q output terminal of d type flip flop is connected with the inversion signal input end of said laser signal maker;

Described driving circuit is made up of the motor drive ic that two output terminals are serially connected with said steer motor field winding two, and the signal input end of said two chip for driving is connected with the I/O mouth that one of single-chip microcomputer has PWM output respectively.

During operate as normal, described single-chip microcomputer is according to program setting, and the modulating pulse of exporting given frequency and dutycycle is to motor drive ic; Motor drive ic output drives steer motor, and steer motor then drives said optical system and rotates to tested direction, at this moment; Laser signal maker driving laser power valve is launched the laser of certain wavelength along optical axis direction; After laser arrives measured surface, be reflected, focus on the back by the reception of laser pick-off pipe and convert electric signal to through the ring-type condenser lens, after electrical signal converted exports the laser signal converter to; Through amplifying, reversing, latch; Convert high-low level at last into and export single-chip microcomputer to, the laser signal converter turn-offs the laser signal maker simultaneously, and LASER Discharge Tube is no longer launched laser; When the laser pick-off pipe does not receive the laser of reflected back; The laser signal converter is then exported opposite level signal to single-chip microcomputer; And open the laser maker once more, the number of times of the switch level that receives in the single-chip microcomputer unit of account time obtains the frequency that current angle following time records.Like this, frequency changes along with the distance of tested distance, and frequency is high, and then tested distance is near, otherwise, then tested distance.Single-chip microcomputer is according to the current frequency that records; Combine the action of each circuit to postpone again, can calculate the distance of the measured object under the current angle, obtain the distance of the measured object of different directions like need fast; Single-chip microcomputer can be according to manual work or program setting; Send pwm signal to motor drive ic, control steer motor rotating speed with turn to, to obtain the distance of all directions measured object.

The described closed loop laser scanning and ranging of the utility model device has following beneficial effect than prior art:

1, mechanical part is simple in structure, owing to adopt PWM electric machine speed regulation mode, can realize the range finding of high speed wide-angle;

2, owing to adopt the scheme of closed-loop fashion switch laser signal generator; Utilize the corresponding relation between switching frequency and the distance to realize range finding at a high speed; Under the prerequisite that does not reduce measuring accuracy; Utilizing clock frequency is that the single-chip microcomputer of tens MHz is the laser signal generative circuit that controllable frequency reaches the GHz level, and the performance requirement to measuring element reduces greatly like this, and cost is also very cheap simultaneously.

Description of drawings

Fig. 1 is the mechanical principle synoptic diagram of a specific embodiment of the said closed loop laser scanning and ranging of the utility model device.

Fig. 2 is the circuit structure block diagram of a specific embodiment of the said closed loop laser scanning and ranging of the utility model device.

Fig. 3 is the circuit theory diagrams of a specific embodiment of the said closed loop laser scanning and ranging of the utility model device.

Fig. 4 is the workflow diagram of a specific embodiment of the said closed loop laser scanning and ranging of the utility model device.

Fig. 5 is the single-chip microcomputer workflow diagram of a specific embodiment of the said closed loop laser scanning and ranging of the utility model device.

Embodiment

Present embodiment is the closed loop laser scanning and ranging device of ARM9 series monolithic LPC3200 control.Referring to Fig. 1 and Fig. 3, this device is made up of, control module 6 and servomotor 5, and wherein, optical system 4 is made up of the ring-type condenser lens 3 that sets gradually, LASER Discharge Tube 1 and laser pick-off pipe 2.Wherein,

The power of described LASER Discharge Tube is not more than 1mW, and electric current is the mA level, and emission wavelength is 650nm; The laser signal maker is made up of MAX3738 high-rate laser chip for driving and the peripheral circuit thereof that U.S. MAXIM company produces, and its operating rate is 1Gbps～2.7Gbps, has extinction ratio control, can produce strong narrow driving pulse;

Described laser pick-off pipe is the avalanche photodide of WV at 120VDC～190VDC; Described its external diameter of ring-type condenser lens is 100mm, and internal diameter is 10mm;

The high speed d type flip flop 74F75 that the reverser chip LF365 that the unity gain high speed integrated operational amplifier OPA656 that described laser signal converter is produced by American TI Company, U.S. NSC company produce, American TI Company are produced connects and composes successively; Wherein, the anode of avalanche photodide is connected with the in-phase input end of high speed integrated operational amplifier OPA656; The output terminal of high speed integrated operational amplifier is connected with the input end of reverser LF365; The output terminal of reverser is connected with the D input end of high speed d type flip flop; High speed d type flip flop Q output terminal connects the inversion signal input end IN-of MAX3738, and the Q output terminal connects the I/O mouth of LPC3200 single-chip microcomputer;

Described motor-drive circuit is made up of the BTS7960 motor drive ic of being produced by Infineon company that two output terminals are serially connected with servomotor field winding two, and the signal input end IN of said two chip for driving is connected with the I/O mouth that one of LPC3200 single-chip microcomputer has PWM output respectively.

Described ARM9 series monolithic control module is made up of LPC3200 single-chip microcomputer and the peripheral circuit thereof that NXP company produces.

Referring to Fig. 4 and Fig. 5 and combine Fig. 3; After LPC3200 single-chip microcomputer U1 initialization was accomplished, single-chip microcomputer was promptly according to the PWM square wave of program setting through PWM output I/O mouth PWM1, PWM2 output certain frequency and dutycycle, if the PWM1 mouth of LPC3200 single-chip microcomputer U1 output PWM square wave; PWM2 keeps output low level; Then the servomotor forward rotation keeps output low level as if the PWM1 mouth, PWM2 mouth output PWM square wave; Servomotor backward rotation then, this moment, the OUT delivery outlet PWM square wave drive servomotor M1 that also exports same modulation of 2 motor drive ic U6, U7 turned to direction to be measured; Simultaneously, the SHUTDOWN pin of high-rate laser chip for driving U2 output electronegative potential, switching tube Q1 is closed; The laser of 650nm wavelength is sent in LASER Discharge Tube D1 conducting, produces diffuse reflection behind laser radiation to the light tight object of direction to be measured; Part laser returns, and converges to the laser pick-off pipe D3 that places on the focus through the ring-type condenser lens, when the laser that receives reaches predetermined strength; Laser pick-off pipe D3 conducting, the in-phase input end step-down of high speed operation amplifier U3, output terminal then output low level to the input end of reverser U4; The output terminal output high level of reverser U4 is to the D input end of d type flip flop U5; Latch output through d type flip flop, the Q output terminal is also exported the inverting input IN-of high level to high speed laser-driven chip U2, and this moment, the OUT+ pin of U2 was drawn high; LASER Discharge Tube D1 is turned off, and the Q output low level is to the I/O mouth DAT17 of single-chip microcomputer U1 simultaneously; D1 is turned off because of LASER Discharge Tube, and when the laser intensity that receives once more as laser pick-off pipe D3 was lower than predetermined value, laser pick-off pipe D3 ended; High speed operation amplifier U3 in-phase input end uprises; The output terminal output high level of high speed operation amplifier is to the input end of reverser U4, and the output terminal output low level of reverser U4 latchs output to the D input end of d type flip flop U5 through d type flip flop; The Q output terminal also output low level to the inverting input IN-of U2; This moment, the OUT+ pin of high-rate laser chip for driving U2 was dragged down, LASER Discharge Tube D1 conducting once more, and the high level of Q output simultaneously is to the I/O mouth DAT17 of single-chip microcomputer U1; SCM program with the process of above-mentioned high-rate laser chip for driving switch as one-period; SCM program calculates the number of received switch periods in the unit interval, promptly draws frequency, combines the action of each circuit to postpone again; Can calculate the distance of the measured object under the current angle; Obtain the distance of the measured object of different directions fast like need, single-chip microcomputer LPC3200 can send pwm signal to motor drive ic U6 and U7 according to manual work or program setting; The rotating speed of control servomotor M1 with turn to, then can obtain the distance of measured object under the different angles.

Claims

1. closed loop laser scanning and ranging device, this device is made up of optical system, control module and steer motor, and wherein said optical system is set gradually by ring-type condenser lens, LASER Discharge Tube and laser pick-off pipe to be formed, it is characterized in that,

The master controller that described control module constitutes with single-chip microcomputer is that the peripheral laser signal maker of core configuration, laser signal converter and steer motor driving circuit are formed; Wherein,

The minimum control system that described master controller is served as reasons and constituted into the AMR9 Series chip;

Described laser signal maker is the laser drive circuit that high-rate laser chip for driving and peripheral circuit thereof constitute, and its output terminal is connected with described LASER Discharge Tube;

Described laser signal converter is the shaping amplification circuit that high speed operation amplifier, reverser, d type flip flop connect and compose successively; Its high speed operation amplifier in-phase input end be connected with described laser pick-off pipe; The Q output terminal of d type flip flop is connected with the I/O mouth of said single-chip microcomputer, and the Q output terminal of d type flip flop is connected with the inversion signal input end of said laser signal maker;

2. a kind of closed loop laser scanning and ranging device according to claim 1 is characterized in that described ARM9 Series chip is LPC3200; Described high-rate laser chip for driving is MAX3738; High speed operation amplifier in the described laser signal converter is that OPA656, reverser are that LF365, d type flip flop are 74F75, and described motor drive ic is BTS7960.