CN2543032Y - Digital geomagnetic position director - Google Patents

Abstract

The utility model relates to a laser guide instrument applied to locating in transport and indication of direction of motion, and a digital pulse detector is adopted to detect the geomagnetism, direction, gradient and speed pulse of a position of a vehicle, wherein from a pulse transformation, coding and console display conducted by a signal processing circuit to a display and an implement conducted by an execution mechanism, the location and position of drivers can always be acquainted by themselves wherever they go. The utility model has the advantages that a defect is avoided of the tendency to be affected by the electromagnetic radiation, weather and topography, as in a case of relying on a signpost or an expensive satellite positioning instrument in a traveling; the structure is simple; the production and appliance cost is low; the operation is easy.

Description

Digital earth magnetism positioning and guiding instrument

Technical field

The utility model relates to a kind of instrument, particularly a kind of guide instrument that is used for communications and transportation location and direction of motion indication.

Background technology

Before the utility model was made, the simulation ground magnetic orientator that is used for aircraft navigation can only be made some location and guide directions rough and discontinuity, and equipment is extremely huge and complicated, is eliminated already.Present traffic above-ground mainly relies on the road sign guiding direction, do not have the place of road sign can only grope to move ahead, so limitation is bigger.Though advanced satellite land is more accurate with orientator, but the location will depend on the position location satellite of foreign country and could work, not only be restricted, and be subject to the interference of electromagnetic radiation, weather and landform, need the data information and the corresponding positioning software of complicated reception and treatment facility and a large amount of electronic charts to work simultaneously, the cost height, usable range is very restricted, and is difficult to penetration and promotion and uses.

Summary of the invention

The purpose of this utility model just is to overcome above-mentioned defective, designs a kind of guide instrument that all means of transports provide continuous location of a convenience and direction guiding that is mainly.

The technical solution of the utility model is:

Principal character is that the output of digit pulse detecting device connects signal processing circuit, signal processing circuit output meets topworks, the digit pulse detecting device is that inner support is suspended on the support arm, the base plate of inner support is provided with rotor, earth magnetism pulse detection coil, testing circuit is connected on the rotor, earth magnetism pulse detection coil is wrapped on the ferrite, magnet is fixed on earth magnetism pulse detection coil top circle centre position, be arranged on photoelectric tube on the inner support top board on the axis of earth magnetism pulse detection coil, edge is provided with two infrared diodes in earth magnetism pulse detection coil top, conductive pellets is suspended on the top board of inner support, the slope detection photo-coupled tube is arranged on the support arm, direction detects photo-coupled tube and is arranged on the internal frame, signal processing circuit is that pulse-detecting circuit output connects pulse conversion circuit, pulse conversion circuit output connects the position pulse driving circuit, the direction of motion indicating circuit, motion position angle indicating circuit, gradient indicating circuit, topworks comprises mechanical driving mechanism, display device, mechanical driving mechanism is that the east-west direction stepper motor is installed on the casing medial surface, the thing screw rod other end that the east-west direction stepper motor is rotationally connected is on the casing another side, thing screw rod and support are rotationally connected, the north and south screw rod is set on the support, the north and south screw rod one end North and South direction stepper motor that is rotationally connected, on the screw rod of north and south electronic compass is set, docking apparatus is set on the casing, display device comprises map and twists on the location collection wheel, the location is collected wheel and is arranged on the casing, is arranged on the orientation pilot lamp on the casing, the position angle shows charactron, the climb and fall pilot lamp, the gradient shows charactron, speed shows charactron, the demonstration charactron of having the records of distance by the log.

Advantage of the present utility model and effect are and can independently locate continuously, adopt the digitized processing signal, the fiduciary level height, can not only guide direction, and can also show position angle, the gradient, speed of present position etc., and volume is little, and production cost and use cost are low.

Description of drawings

Fig. 1-the utility model functional-block diagram;

Fig. 2-digit pulse detector arrangement front view;

Fig. 3-digit pulse detector arrangement side view;

Fig. 4-topworks's synoptic diagram;

Fig. 5-the utility model panel figure;

Pulse-detecting circuit figure in Fig. 6-signal processing circuit;

Pulse conversion circuit figure in Fig. 7-signal processing circuit;

Direction indication in Fig. 8-signal processing circuit, position angle display circuit figure;

Direction indication decoding scheme in Fig. 9-signal processing circuit;

The gradient in Figure 10-signal processing circuit, speed, the digital control decoding scheme that shows of having the records of distance by the log;

Motion orientation indicating circuit figure in Figure 11-signal processing circuit;

Motor-drive circuit figure in Figure 12-executive circuit;

Location in Figure 13-executive circuit, direction indicating circuit figure.

Embodiment

As shown in Figure 1, connection signal, functional diagram between each circuit have been described.

As Fig. 2, shown in Figure 3, the inner support 10 of digit pulse detecting device is suspended on the support arm 15, horizontality, and the supporting shaft of its suspension is provided with damper 11, and damping oil is arranged in it; Inner support 10 is provided with rotor 8, infrared transmitting tube 3, direction detection arc strip 5, adjusts screw 6, direction pulse detection photo-coupled tube 4, magnet 14, conductive pellets 13, power lead 2, earth magnetism pulse detection photoelectric tube 1, wherein be provided with on the rotor 8 earth magnetism pulse detection coil 7, magnetic sensor circuit 9, make its dead in line; On support arm 15 side plates slope detection photo-coupled tube 12 is set; Earth magnetism pulse detection coil 7 is wrapped on the cylindrical high magnetic conductivity ferrite, is in horizontality; Magnet 14 is fixed on the top circle centre position of pulse detection coil 7, and two infrared diodes 3 are fixed on the top place of earth magnetism pulse detection coil 7; Direction detects the outer edge that arc strip 5 is fixed on rotor 8, and the arc length of arc strip 5 is 1/4th of a rotation round, adjusts screw 6 and is in the position of regulating arc strip 5; Direction detects the orientation of its axis tangential movement direction of photo-coupled tube 4, differs 90 degree with slope detection photo-coupled tube 12 orientation; Detect photoelectric tube 1 on the axis of earth magnetism pulse detection coil 7 at the earth magnetism on inner support 10 top boards, the conductive pellets 13 that is suspended on inner support 10 top boards is connected with power lead 2.

As shown in Figure 4, thing motor 16 drives with thing coordinate screw rod 17 and is connected, thing coordinate screw rod 17 drives with support 22 and is connected, motor 18 is connected with north and south coordinate screw rod 19, thing motor 16 is installed on the instrument side, north and south motor 18, north and south coordinate screw rod 19 are installed on the support 22, and the two ends of north and south coordinate screw rod 19 are in two metal guide rods 21, slidably; Orientation electronic compass 20 is arranged on the north and south coordinate screw rod 19, installation direction pilot lamp 24, centralized positioning pilot lamp 36 on it.

As shown in Figure 5, ground Figure 23 in location twists in to collect on the wheel 35, orientation pilot lamp 29, position angle display lamp 26 is set, the display lamp 28 of having the records of distance by the log, signal jack 32, power switch 30, supply hub 33, power safety hole 31 on it.

As shown in Figure 6, the earth magnetism pulse-detecting circuit, earth magnetism pulse detection coil 7 among Fig. 1, Fig. 2, conductive pellets 13 are formed resonant circuit with electric capacity 38, detected ground magnetic-pulse is added to the inverting input of zero-crossing comparator 39 behind resonance step-up, by after the magnetic-pulse zero passage phase-detection over the ground, drive infrared transmitting tube 3 through triode and send infrared pulse, detect by earth magnetism pulse detection photoelectric tube 1, carry out phase-detection through zero-crossing comparator 40, output earth magnetism rectangular pulse signal (1); The direction signal testing circuit is added to the inverting input of zero-crossing comparator 44, outbound course rectangular pulse signal (2) with the direction pulse detection photo-coupled tube 4 detected direction pulse signals among Fig. 1, Fig. 2; The slope detection circuit is added to the inverting input of zero-crossing comparator 47 with the 12 detected gradient pulse signals of the slope detection photo-coupled tube among Fig. 1, Fig. 2, output gradient rectangular pulse signal (3); The velocity pulse testing circuit detects velocity pulse photoelectric tube 41 or is added to zero comparator 42 by magnetic induction coil 50 detected speed pulse signals and carries out phase-detection, after 51 conversion of pulsewidth translation circuit, and output speed pulse signal (4).

As shown in Figure 7, pulse conversion circuit.After 52,53 conversion of pulsewidth translation circuit, exporting two pulsewidths is 1/4th of drive motor swing circle with the earth magnetism rectangular pulse signal (1) exported among Fig. 6, two earth magnetism rect.p.s of phase phasic difference 180 degree; After 58 conversion of pulsewidth translation circuit, exporting two pulsewidths is 1/4th of the 2 motor cycles of drive motor with the direction rectangular pulse signal (2) exported among Fig. 6, the both direction rect.p. of phase phasic difference 90 degree; Two earth magnetism rectangles are carried out the logic phase demodulation with the both direction rect.p. respectively in four AND gate circuits 55, export four and represent north, east, south and the west to durection component pulse (5), (6), (7) and (8), again with this four direction component pulse respectively with Fig. 6 in the speed pulse signal (4) exported carry out logical process by four AND gate circuits 56, output is northern respectively, east, south and west be four speed dispense-pulse upwards, with north, the speed dispense-pulse that south makes progress obtains northern southern velocity pulse (9) after by OR-circuit 57 unions, obtains thing velocity pulse (10) equally.

Still as shown in Figure 7, with gradient pulse (3) in the accompanying drawing 6 under horizontality through circuit 59 be transformed to direction pulse (2) phase place differ respectively 90 the degree, width is the gradient pulse of drive motor swing circle 1/4th, the equidirectional arteries and veins clock of gradient pulse after the conversion (2) is handled gradient component pulse (11) and (12) of output ascents and descents degree with door in gradient component phase discriminator 42.Ascents and descents component pulse (11) and (12) are exported gradient component pulse (14) by OR-circuit 43 unions; With time clock AND gate logic in circuit 45 of gradient component pulse (14) and 60 outputs of grade correction clock signal generator, output grade correction data pulse (13); The grade correction circuit is that grade correction data pulse (13) is added to the clock end of proofreading and correct code translator 62, the Q1 of gradient component pulse count decoding frequency divider 103 among Figure 10 output is brought out defeated gradient component pulse (38) be added to the clear terminal of proofreading and correct code translator 62 and latch end, proofread and correct decoding; To proofread and correct code translator 62 output terminals from Q1-Q12 per two by diode and be unified into A1, A2, A3, A4, A5, six output terminals of A6, with these six output terminals by after the resistance eutral grounding dividing potential drop respectively with six output terminals of Q10-Q15 of north and south velocity pulse counting decoder 61, and six output terminals of the q10-q15 of east-west direction velocity pulse counting decoder 63 AND gate logic in circuit 64, by corresponding OR circuit 65 unions of the warp of the pulse behind circuit 64 and the gate logic, the pulse of output by phase inverter 66 anti-phase after, one the tunnel is added to the clear terminal of speed counting decoder 61 and 63, another road is added to the input end of AND gate circuit 67, respectively and north and south, thing velocity pulse (9), (10) AND gate logic, the north and south velocity pulse (15) after the output terminal output grade correction, thing velocity pulse (16).

As shown in Figure 8, direction indicated number circuit, be pulse (5), (6), (7), (8) with durection component phase detector output among Fig. 7, in direction level treatment circuit 68, be added to union in four OR-circuits after by the capacitive coupling electric resistance partial pressure, export four direction level (17), (18), (19), (20) respectively from output terminal with its rp pulse; In order to make the direction level equalization of output, output termination rc filter circuit.Direction level (17) and (18), (18) and (19), (19) and (20), (20) and (17) are carried out the AND gate logic respectively in motion orientation level determiner 69, the level of output is exported four through twice anti-phase back and is represented the level (23) of the level (21) in east northeast orientation, the level (22) in orientation, the southeast, position, southern west, the level (24) of northwest position respectively.Durection component pulse among Fig. 7, (5), (6), (7), (8) are carried out the AND gate logic with orientation level (21), (22), (23), (24) respectively after anti-phase twice in component motion pulse decoder 70 select, through OR-circuit 71 unions, the component pulse of output is the durection component pulse (25) on the present direction of motion with the durection component pulse that chooses.

Still as shown in Figure 8, be that the position angle is shown that gating pulse (25) is divided into two-way in the display circuit of position angle, the count decoding frequency divider 72 of leading up to carries out 16 frequency divisions with pulse (25), durection component pulse (30) behind the frequency division is added to latching of position angle display decoder 73 holds and clear terminal, the time clock of another road and position angle read clock pulse producer 75 outputs is in circuit 76 after the AND gate, be added to the clock end of position angle display decoder 73 after twice of the position angle video data pulse of output is anti-phase, drive by code translator 73 decodings, in charactron 74, just show orientation angles in motion.

Direction indicating circuit during the positive dirction motion, be that A, B, C, D four-input terminal that direction level (17), (18), (19), (20) are added to positive dirction code translator 77 respectively for twice after anti-phase are deciphered, export the direction indication high level in positive north, due east, due south, positive west respectively from Q1, Q2, Q4, Q8, through triode 78,79,80,81 driving direction pilot lamp 82,83,84,85 is luminous, indicates present travel direction.

Still as shown in Figure 8, the clock frequency of position angle read clock generator 75 outputs is 360 times of drive motor gyro frequency, by the maximum orientation angles that demonstrates in each orientation after the digital decoder for decoding in position angle is 90 degree, and four position angle sums are 360 degree.

As shown in Figure 9, direction indication decoding scheme, at first with the time clock of durection component pulse (25) and direction telltable clock generator 90 outputs, outbound course designation data pulse (31) after the AND gate logic in circuit 91, direction designation data pulse (31) is added to four 4 line-16 line direction code translators 86,87,88,89 input end of clock, direction behind 16 frequency divisions indication component pulse (30) among Fig. 8 is added to four direction indication code translator 86,87,88,89 clear terminal and latch end, four orientation level (21) with 69 outputs of level identification circuit in orientation among Fig. 8, (22), (23), (24) be added to four direction code translator 86 respectively after anti-phase, 87,88,89 permission end, export 15 directions indication level in east northeast orientation from the Q1-Q15 output terminal of direction code translator 86, export 15 directions indication level in orientation, the southeast from the Q1-Q15 output terminal of code translator 87, export 15 direction indication level of position, southern west from the Q1-Q15 output terminal of code translator 88, export 15 directions indication level of northwest position from the Q1-Q15 output terminal of code translator 89, be added to the base stage that drives triode 93 with behind the velocity pulse (41) of each output terminal after and the gate logic, drive that the blinker 24 of corresponding orientation is luminous indicates present direction of motion by flashing circuit generator 92 and frequency division.The pulsed frequency of direction telltable clock generator output is 60 times of drive motor gyro frequency.

As shown in figure 10, gradient decoding scheme is uphill gradient component pulse (11) and the downward grades component pulse (12) with 42 outputs of gradient component phase detector among Fig. 7, in gradient level treatment circuit 95 with its rp pulse through behind the capacitive coupling electric resistance partial pressure in two OR circuit union, output upward slope component level (32) and descending component level (33), and in order to make gradient component level equalization, output termination rc filter circuit; Upward slope component level (32) and descending component level (33) are passed through to export gradient level (39) after the OR circuit addition; The gradient data pulse that the time clock of the gradient component pulse among Fig. 7 (14) a road and gradient read clock generator 101 outputs is exported after circuit 102 AND gate logics is added to the clock end of gradient display decoder 99, another road of gradient component pulse (14) is added to carries out 16 frequency divisions in the count decoding frequency divider 103, component pulse (38) behind the Q1 output frequency division, one the tunnel is added to the zero clearing of grade correction code translator 62 among Fig. 7, latch end, another road is added to the end that latchs of gradient display decoder 99 after anti-phase, pulse gradient level (39) advances logical process in circuit 96 after is added to the clear terminal of gradient display decoder 99, from charactron 100, just show the gradient; Upward slope component level (32) is added in the upward slope indicating circuit 104, descending component level (33) is added to just to indicate in the descending indicating circuit 105 be to go up a slope or descending now.Adjust the output frequency of gradient read clock pulse producer 101, the gradient that charactron is demonstrated is consistent with actual grade.

Speed decoding display circuit carries out work by code translator and charactron in the circuit 106; The demonstration of having the records of distance by the log is to carry out work by code translator in the circuit 107 and charactron.

As shown in figure 11, it is with north and south velocity pulse (15) after the grade correction among Fig. 7 and thing velocity pulse (16) that the location ratio is adjusted circuit, respectively through counter 116 and 117 countings, the system of counting is by switch 111,112,113 change, north and south after transformation of scale, the thing velocity pulse is respectively through pulsewidth translation circuit 119, north and south velocity pulse (34) and power supply gating pulse (35) are exported in 120 conversion and twice anti-phase back, thing velocity pulse (36) power supply gating pulse (37), north and south velocity pulse (34) is added to stairstep signal input end in the step-by-step impulse generator 123, the north among Fig. 7 is added to direction control input end in the step-by-step impulse generator 123 to component pulse (5) after circuit 122 time-delay, the step-by-step impulse of step-by-step impulse generator 123 outputs, by driver 124 drive stepping motor 125, on the coordinate of north and south, do the stepping location.Power supply gating pulse (35) is supplied with stepper motor 125 power supplys by circuit 126.The velocity pulse (36) of east-west direction is added to stairstep signal input end in the step-by-step impulse generator 129, Fig. 7 Middle East durection component pulse (6) is added to direction control input end in the step-by-step impulse generator 129 after delay circuit 128 time-delay, does the stepping location through driver 130 drive stepping motor 131 at the thing coordinate from the step-by-step impulse of step-by-step impulse generator 129 outputs.Power supply gating pulse (37) is supplied with stepper motor 131 power supplys by circuit 132.The pulse switch 115 of manual adjustment position, the direction control switch 121 of North and South direction adjustment usefulness, the direction control switch 127 of east-west direction adjustment usefulness, the pulse producer 114 of adjustment position.

As shown in figure 12, the control circuit of direction of motion pilot lamp flicker, be that the velocity pulse (4) that will export among Fig. 6 is added to after by the capacitive coupling electric resistance partial pressure with its rp pulse in velocity level treatment circuit 133 and carries out union in the OR circuit, the level of output is after phase inverter 134 is anti-phase, the velocity level (40) of output is added to the Vss end of scintillation pulse frequency-dividing counter 135, velocity pulse behind the frequency division (41) is indicated code translator 86 with direction respectively, 87,88,89 output level is undertaken and gate logic by the AND circuit in the scintillation pulse generator 92, to assign to the driving triode 93 that is added to blinker with the pulse behind the gate logic, in 94, make blinker 24 and positioning light 36 flickers in the direction of motion indication electronic compass.Stable for the velocity level that makes 133 outputs of velocity level treatment circuit, its output terminal adds capacitance-resistance and considers wave circuit.

As shown in figure 13, motion orientation indicating circuit, be with east northeast orientation level (21), the southeast bit level (22), southern west bit level (23), northwest position level (24) among Fig. 8 respectively through phase inverter 138 twice anti-phase after, be added to the base stage of orientation indication driving triode 139,140,141,142, thereby make light emitting diode 143 indication east northeast orientation, light emitting diode 144 indication orientation, the southeast, light emitting diode 145 indication positions, southern west, light emitting diode 146 indication northwest positions.

As Fig. 8, Figure 10, shown in Figure 12, the coupling capacitance in its circuit and the product of divider resistance should much larger than the coupling pulse width (RC＞＞tw), and divider resistance should be the minimum value of the normal upset of gate circuit, the pulse that can guarantee to be coupled to the gate circuit input end like this is indeformable, and make the input end of gate circuit when having pulse, not be in low level by the rapid discharge of resistance, gate circuit is overturn accurately by the width and the phase place of pulse.

More than phase inverter in all circuit all adopt CM0S circuit Si Mite to trigger phase inverter.

The detection of earth magnetism, direction, the gradient is the key component of positioning and guiding instrument, and the inner support [10], support arm 15, fixed screw, the adjustment screw that constitute the digit pulse detecting device all should be non magnetic.The base plate of the support arm of detecting device [15] should be installed on the plane that parallels with the moving object base plate, the axis of direction detection photoelectric tube [4] should point to the horizontal direction of motion, object can not be magnetic in 50 centimeters scopes around the detecting device, in order to avoid to its interference, what earth magnetism pulse detection amplifying circuit element should be firm in the detecting device is welded on the circuit board [9], and circuit board [9] is fixed on the drive motor rotor [8].It is relatively good that drive motor adopts computer disk drive motor in the detecting device.In order to prevent the influence of outer bound pair detecting device, detecting device is installed in the nonmagnetic protective cover.

Speed detector [41], [50] are installed on the vehicle wheel frame of traveling vehicle, and the rotating speed of wheel is converted to electric impulse signal, and the frequency of electric impulse signal has been represented the size of speed.

Thing, north and south positioning screw should adopt the screw rod of same pitch, and the positioning motor power on the east-west direction should be bigger than the positioning motor power on the North and South direction, and driving arm [22] moves upward between east and west smoothly like this.Electronic compass [20] diameter that is installed on the locating support [22] is no more than 2 centimetres.

The location map is that the positioning and guiding instrument by standard moves on the spot to draw and.

The positioning and guiding instrument also can add corresponding software with location digital signal and the output of direction of motion digital signal, demonstrates travel direction and position by computer monitor.

Claims (10)

1. digital earth magnetism positioning and guiding instrument, it is characterized in that the output of digit pulse detecting device connects signal processing circuit, signal processing circuit output meets topworks, the digit pulse detecting device is that inner support is suspended on the support arm, the base plate of inner support is provided with rotor, earth magnetism pulse detection coil, testing circuit is connected on the rotor, earth magnetism pulse detection coil is wrapped on the ferrite, magnet is fixed on earth magnetism pulse detection coil top circle centre position, be arranged on photoelectric tube on the inner support top board on the axis of earth magnetism pulse detection coil, edge is provided with two infrared diodes in earth magnetism pulse detection coil top, conductive pellets is suspended on the top board of inner support, the slope detection photo-coupled tube is arranged on the support arm, direction detects photo-coupled tube and is arranged on the internal frame, signal processing circuit is that pulse-detecting circuit output connects pulse conversion circuit, pulse conversion circuit output connects the position pulse driving circuit, the direction of motion indicating circuit, motion position angle indicating circuit, gradient indicating circuit, topworks comprises mechanical driving mechanism, display device, mechanical driving mechanism is that the east-west direction stepper motor is installed on the casing medial surface, the thing screw rod other end that the east-west direction stepper motor is rotationally connected is on the casing another side, thing screw rod and support are rotationally connected, the north and south screw rod is set on the support, the north and south screw rod one end North and South direction stepper motor that is rotationally connected, on the screw rod of north and south electronic compass is set, docking apparatus is set on the casing, display device comprises map and twists on the location collection wheel, the location is collected wheel and is arranged on the casing, is arranged on the orientation pilot lamp on the casing, the position angle shows charactron, the climb and fall pilot lamp, the gradient shows charactron, speed shows charactron, the demonstration charactron of having the records of distance by the log.

2. digital earth magnetism positioning and guiding instrument according to claim 1 is characterized in that inner support hangs on the bolster on the support arm damper is set, and damping oil is arranged in the damper.

3. digital earth magnetism positioning and guiding instrument according to claim 1 is characterized in that slope detection photo-coupled tube and direction detect photo-coupled tube and differ 90 degree on the orientation.

4. digital earth magnetism positioning and guiding instrument according to claim 1 is characterized in that conductive pellets is connected with the magnet contact.

5. digital earth magnetism positioning and guiding instrument according to claim 1 is characterized in that pulse-detecting circuit comprises earth magnetism pulse-detecting circuit, direction pulse-detecting circuit, gradient pulse-detecting circuit, velocity pulse testing circuit.

6. digital building site magnetic orientation guide instrument according to claim 1 is characterized in that pulse conversion circuit comprises earth magnetism pulse conversion circuit, direction pulse conversion circuit, gradient pulse conversion circuit, velocity pulse translation circuit.

7. according to the described digital earth magnetism positioning and guiding instrument of claim 1, it is characterized in that the support two ends are in the guide rod of casing two inboards.

8. digital earth magnetism positioning and guiding instrument according to claim 1 is characterized in that being provided with on the electronic compass positioning light, blinker.

9. digital earth magnetism positioning and guiding instrument according to claim 1 is characterized in that docking apparatus comprises pulse detection signals input jack, power switch, power supply input jack, power safety jack.

10. digital earth magnetism positioning and guiding instrument according to claim 1, it is characterized in that display device comprises map and twists on the location collection wheel, the location is collected wheel and is arranged on the casing, and the orientation pilot lamp, the position angle that are arranged on the casing show that charactron, climb and fall pilot lamp, the gradient show that charactron, speed show charactron, the demonstration charactron of having the records of distance by the log.

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