CN104240785B - A kind of multi-diaphragm collimator blade anti-collision control method - Google Patents
A kind of multi-diaphragm collimator blade anti-collision control method Download PDFInfo
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- CN104240785B CN104240785B CN201410471636.4A CN201410471636A CN104240785B CN 104240785 B CN104240785 B CN 104240785B CN 201410471636 A CN201410471636 A CN 201410471636A CN 104240785 B CN104240785 B CN 104240785B
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Abstract
This multi-diaphragm collimator blade anti-collision control method, when comprising the steps: static intensity modulating, difference according to real time position and blade movement to target location is compared to the speed of service of the motor that continuous transfer drive moving vane moves with the difference of blade initial position with blade movement to target location, when blade real time position is closer to target location, the motor speed of service is the slowest, can effectively prevent the collision between the blade caused during two groups of blades closedowns.When dynamically adjusting strong, during by judging that motor advances or retreats, the pulse number that the real electrical machinery position coder recorded in real time by i-th Ziye is sent out and higher limit SlidePosH and lower limit SlidePosL are compared to judge that motor is brake, inertia is utilized to continue slide forward or make motor certain speed Vo [i] be rotated further, so that the position that motor operation is actually reached is the most identical with target location, its error is made to guarantee in ± e, prevent blade collision from causing the faults such as mechanical damage, prevent the sand permeation of vane end faces.
Description
Technical field
The present invention relates to medical electronics technical field, be specifically related to a kind of multi-diaphragm collimator method of controlling vanes.
Background technology
Multi-diaphragm collimator is the stereotaxic radiosurgery armarium of a kind of advanced person, can coordinate linear accelerator or cobalt
-60 machines carry out conformal intensity modulated treatment to tumor, thus reach to improve the radiotherapy ratio of gains (the most to greatest extent
The dosage of lonizing radiation is focused in pathological changes, kills tumor cell, and make the normal structure of surrounding and organ be subject to less
Or from unnecessary irradiation) purpose.It it is one of the capital equipment of current oncotherapy.It is by A,
Some lead baffle plates traditional to high density tungsten alloy blade replacement that B two groups arranges in opposite directions are to shield ray, with phase
The motor answering logarithm drives blade and vane group respectively, is detected and control the position of blade by control system, soon
Speed forms the launched field shape required, the corresponding actions of combined treatment machine, reaches conformal or adjusts strong purpose.Blade
The detection of position, is typically calculated by the number of rotary encoder feedback pulse.
Blade quickly forms the process of launched field shape, be controller control two groups of relative blade move toward one another rapidly or
Motion is surrounded and is formed in the same direction, this collision caused the most unavoidably between relative vane, cause connect blade leading screw or
Drive the motor damage of blade, have a strong impact on normal treatment.During especially " dynamically adjusting strong ", because
The speed of service of blade is very fast, and makees not stop in the middle of persistent movement, and collide between relative vane is several
Rate rises significantly.For avoiding blade pair relatively to collide faults such as causing mechanical damage, current Main is
Leave a little gap, but such a process increases the sand permeation of not fully closed vane end faces, human body is had necessarily
Harm.
Summary of the invention
The present invention is in order to overcome the deficiency of above technology, it is provided that a kind of raising leaf position control accuracy, prevents blade
The multi-diaphragm collimator blade anti-collision control method collided.
The present invention overcomes its technical problem be the technical scheme is that
This multi-diaphragm collimator blade anti-collision control method, comprises the steps:
A) when two groups of blades of multi-diaphragm collimator A, B are closed, minimum range is set as 0.1mm, according to formula
It is calculated position error e of A, B blade, the pulse that when N is blade operation 1mm in formula, encoder sends
Number；
B) during static intensity modulating, as | p-S | ＞ PMax1, the motor speed of service driving blade is V_Max, when
During PMax2 ＜ | p-S | ＜ PMax1, the motor speed of service driving blade is V_Normal, when
The motor speed of service driving blade during PMax3 ＜ | p-S | ＜ PMax2 is V_Min, as | p-S | ＜ PMin
Time, the driving voltage that host computer applies to the motor driving blade is 0, and blade stop motion voluntarily, in formula
PMax1=3/4 | P-S |, PMax2=1/2 | P-S |, PMax3=1/3 | P-S |, PMin=1/5 | P-S |, p
The pulse number sent for blade real time position encoder, S is that blade movement is sent out to target location encoder is required
The pulse number gone out, P is the blade pulse number that encoder sends when being positioned at initial position, V_Max=10 ×
N/S, V_Normal=6 × N/S, V_Min=2 × N/S；
C), as | p-S | ＜ PMin, after blade stops, calculating blade stop position L encoder by formula | L-S | and send out
The difference of the pulse number sent needed for the pulse number gone out and blade movement to target location encoder absolute
Value, as | L-S | ＞ e, it is the PWM of 100% that host computer applies 4 dutycycles to the motor driving blade
Pulse；
When d) dynamically adjusting strong, host computer obtains a Ziye positional information at interval of the T moment, and host computer measures motor
Present speed Vr [i], natural coasting distance after calculating motor brake according to formula S lideLen=k × Vr [i]
The pulse number SlideLen that encoder is sent, in formula, k value is 3-5, according to formula S lidePosL=
TP [i]-SlideLen calculate brake rear motor lower limit encoder pulse number SlidePosL and according to
Formula S lidePosH=TP [i]+SlideLen calculates brake rear motor higher limit encoder pulse number
SlidePosH, in formula, TP [i] is positioned at, by i-th Ziye, the pulse number that target location encoder is sent；
E) advance when motor, if during P [i] ＜ SlidePosH, motor brake, if during P [i] ＞ SlidePosH, on
Position machine given speed Vo [i] makes motor be rotated further, and Vo [i]=| TP [i]-P [i] |/(1.1 × T-T [i]), in formula
The pulse number that P [i] is sent out by the real electrical machinery position coder that current i-th Ziye records in real time, T [i] is
Current time；
F) when motor retreats, if during P [i] ＞ SlidePosL, motor brake, if during P [i] ＜ SlidePos,
Host computer given speed Vo [i] makes motor be rotated further, Vo [i]=| TP [i]-P [i] |/(1.1 × T-T [i]), formula
The pulse number that middle P [i] is sent out by the real electrical machinery position coder that current i-th Ziye records in real time, T [i]
For current time.
In order to realize monitoring, it is additionally included in step b) and sends blade position coding at interval of 50ms to host computer
The pulse number that device sends, the step of motion between ipc monitor relative vane.
In order to ensure blade stop position within the scope of allowable error, it is additionally included in step c) host computer to driving
At interval of 100ms by upper computer detection after the pwm pulse that motor 4 dutycycles of applying are 100% of blade
1 | L-S | is the most still more than e, if | L-S | is ＞ e, then repeats step c), until during | L-S | ＜ e,
Stop detection.
In order to rationally arrange the moment, T=50ms in above-mentioned steps d).
The invention has the beneficial effects as follows: during static intensity modulating, according to the difference of real time position with blade movement to target location
Value is compared to continuous transfer drive moving vane fortune with the difference of blade initial position with blade movement to target location
The speed of service of dynamic motor, when blade real time position is closer to target location, the motor speed of service is the slowest,
Can effectively prevent the collision between the blade caused during two groups of blades closedowns.
When dynamically adjusting strong, during by judging that motor advances or retreats, the real electrical machinery that i-th Ziye is recorded in real time
The pulse number that position coder is sent out compares with higher limit SlidePosH and lower limit SlidePosL
Relatively judge that motor is brake, utilize inertia to continue to slide forward or make motor certain speed Vo [i] to continue to turn
Dynamic, so that the position that motor operation is actually reached is the most identical with target location so that it is error guarantees at ± e
In, prevent blade collision from causing the faults such as mechanical damage, reduce the gap between blade, prevent the blade can not be complete
Complete closure causes the sand permeation of vane end faces, the problem having certain harm to human body.
Accompanying drawing explanation
Fig. 1 is blade velocity and the location diagram of the present invention
Fig. 2 is blade velocity and the driving voltage graph of a relation of the present invention；
Fig. 3 is target location and higher limit and lower limit corresponding relation figure；
Physical location and higher limit and target location corresponding relation figure during the advance of Fig. 4 motor；
Physical location and lower higher limit and target location corresponding relation figure in Fig. 5 motor fallback procedures.
Detailed description of the invention
The present invention will be further described for 1 to accompanying drawing 5 below in conjunction with the accompanying drawings.
This multi-diaphragm collimator blade anti-collision control method, comprises the steps:
(1) current, for the multi-diaphragm collimator of non-switch type, the movement of its blade is by motor drag leading screw
Mode completes, and the rotary motion of motor is changed into the linear motion of blade by leading screw.And the motion of motor
Speed, is carried out by the way of pulse width modulation (PWM).Therefore, for convenience of calculation, can be by leaf
The distance transform that sheet moves is encoder pulse number.Narrow spacing when two groups of blades of multi-diaphragm collimator A, B are closed
From being set as 0.1mm, according to formulaIt is calculated position error e of A, B blade, N in formula
The pulse number that when running 1mm for blade, encoder sends.Assuming that 1mm correspondence encoder pulse number is 100,
Then during two groups of blade Guan Bis of A, B, minimum spacing is 10 pulses.Accordingly, A, B case blade position error should be little
In 5 pulses.
(2) as shown in Figure 1, during static intensity modulating, as | p-S | ＞ PMax1, the motor of blade is driven to run speed
Degree is V_Max, and as PMax2 ＜ | p-S | ＜ PMax1, the motor speed of service of driving blade is
V_Normal, the motor speed of service driving blade as PMax3 ＜ | p-S | ＜ PMax2 is V_Min, when
During | p-S | ＜ PMin, the driving voltage that host computer applies to the motor driving blade is 0, and blade stops voluntarily
Motion, PMax1=3/4 | P-S | in formula, PMax2=1/2 | P-S |, PMax3=1/3 | P-S |,
PMin=1/5 | P-S |, p are the pulse number that blade real time position encoder sends, and S is that blade movement is to mesh
The pulse number sent needed for cursor position encoder, P is the blade pulse that encoder sends when being positioned at initial position
Number, V_Max=10 × N/S, V_Normal=6 × N/S, V_Min=2 × N/S.According to real time position p with
Blade movement is carried out to the difference of target location with the difference of blade initial position with blade movement to target location
Relatively carry out the speed of service of the motor of continuous transfer drive moving vane motion, when blade real time position is closer to target location
Time the motor speed of service the slowest, can effectively prevent the collision between the blade that two groups of blades cause when closing.
(3), as shown in Figure 2, as | p-S | ＜ PMin, after blade stops, calculating blade by formula | L-S | and stop
Stop bit puts the pulse sent needed for pulse number that L encoder sends and blade movement to target location encoder
The absolute value of the difference of number, as | L-S | ＞ e, host computer applies 4 duties to the motor driving blade
Than the pwm pulse being 100%.Host computer makes electricity by sending the pwm pulse that 4 dutycycles are 100%
Machine starts, and drives blade again to move so that it is the pulse number that stop position L encoder sends is transported with blade
The absolute value of the difference moving the pulse number sent needed for the encoder of target location is less than e, ensures that leaf
The positioning precision of sheet, further ensure that and will not collide between blade.
(4) as shown in Figure 3, when dynamically adjusting strong, host computer obtains a Ziye positional information at interval of the T moment,
Host computer measures the present speed Vr [i] of motor, calculates motor according to formula S lideLen=k × Vr [i] and stops
The pulse number SlideLen that after car, natural coasting distance encoder is sent, in formula, k value is 3-5, according to
Formula S lidePosL=TP [i]-SlideLen calculates brake rear motor lower limit encoder pulse number
SlidePosL and according to formula S lidePosH=TP [i]+SlideLen calculate brake rear motor higher limit
Encoder pulse number SlidePosH, in formula, TP [i] is positioned at target location encoder by i-th Ziye and is sent
Pulse number.(5) as shown in Figure 4, when motor advances, if during P [i] ＜ SlidePosH, motor
Brake, if during P [i] ＞ SlidePosH, host computer given speed Vo [i] makes motor be rotated further, Vo [i]=
| TP [i]-P [i] |/(1.1 × T-T [i]), in formula, P [i] is the real electrical machinery position that current i-th Ziye records in real time
The pulse number that encoder is sent out, T [i] is current time.(6) as shown in Figure 5, when motor retreats,
If during P [i] ＞ SlidePosL, motor brake, if during P [i] ＜ SlidePos, host computer given speed Vo [i]
Making motor be rotated further, Vo [i]=| TP [i]-P [i] |/(1.1 × T-T [i]), in formula, P [i] is current i-th
The pulse number that the wild real electrical machinery position coder recorded in real time is sent out, T [i] is current time.By judging
When motor advances or retreats, the pulse that the real electrical machinery position coder recorded in real time by i-th Ziye is sent out
Number P [i] and higher limit SlidePosH and lower limit SlidePosL are compared to judge that motor is to stop
Car, utilizes inertia to continue slide forward or make motor certain speed Vo [i] be rotated further, so that motor fortune
The position that is actually reached of row is the most identical with target location so that it is error guarantees, in ± e, to prevent blade from colliding
Cause the faults such as mechanical damage, reduce the gap between blade, prevent blade from of completely closed can not cause blade end
The sand permeation in face, the problem that human body is had certain harm.
It is additionally included in step (2) and sends, to host computer, the pulse that blade position encoder sends at interval of 50ms
Number, the step of motion between ipc monitor relative vane.So that host computer knows the position of blade in time,
Improve monitoring capacity.
Being additionally included in host computer in step (3) is the PWM of 100% to motor 4 dutycycles of applying of driving blade
E the most still it is more than at interval of 100ms by 1 | L-S | of upper computer detection after pulse, if | L-S | is ＞ e,
Then repeat step c), until during | L-S | ＜ e, stopping detection.Detected by interval 100ms, permissible
Guarantee that blade stop position, within the scope of allowable error, further increases anti-collision capacity, improve reliable
Property.
T=50ms in step (4).A Ziye positional information is obtained, it is meant that at 50ms at interval of the 50ms moment
Interior motor should arrive given Ziye position, can affect efficiency more than 50ms, can bring to motor less than 50ms
Excessive load, affects the life-span of motor.
Claims (4)
1. a multi-diaphragm collimator blade anti-collision control method, it is characterised in that: comprise the steps:
A) when two groups of blades of multi-diaphragm collimator A, B are closed, minimum range is set as 0.1mm, according to formula
It is calculated position error e of A, B blade, the pulse that when N is blade operation 1mm in formula, encoder sends
Number；
B) during static intensity modulating, as | p-S | ＞ PMax1, the motor speed of service driving blade is V_Max, when
During PMax2 ＜ | p-S | ＜ PMax1, the motor speed of service driving blade is V_Normal, when
The motor speed of service driving blade during PMax3 ＜ | p-S | ＜ PMax2 is V_Min, as | p-S | ＜ PMin
Time, the driving voltage that host computer applies to the motor driving blade is 0, and blade stop motion voluntarily, in formula
PMax1=3/4 | P-S |, PMax2=1/2 | P-S |, PMax3=1/3 | P-S |, PMin=1/5 | P-S |, p
The pulse number sent for blade real time position encoder, S is that blade movement is sent out to target location encoder is required
The pulse number gone out, P is the blade pulse number that encoder sends when being positioned at initial position, V_Max=10 ×
N/S, V_Normal=6 × N/S, V_Min=2 × N/S；
C), as | p-S | ＜ PMin, after blade stops, calculating blade stop position L encoder by formula | L-S | and send out
The difference of the pulse number sent needed for the pulse number gone out and blade movement to target location encoder absolute
Value, as | L-S | ＞ e, it is the PWM of 100% that host computer applies 4 dutycycles to the motor driving blade
Pulse；
When d) dynamically adjusting strong, host computer obtains a Ziye positional information at interval of the T moment, and host computer measures motor
Present speed Vr [i], natural coasting distance after calculating motor brake according to formula S lideLen=k × Vr [i]
The pulse number SlideLen that encoder is sent, in formula, k value is 3-5, according to formula S lidePosL=
TP [i]-SlideLen calculate brake rear motor lower limit encoder pulse number SlidePosL and according to
Formula S lidePosH=TP [i]+SlideLen calculates brake rear motor higher limit encoder pulse number
SlidePosH, in formula, TP [i] is positioned at, by i-th Ziye, the pulse number that target location encoder is sent；
E) advance when motor, if during P [i] ＜ SlidePosH, motor brake, if during P [i] ＞ SlidePosH, on
Position machine given speed Vo [i] makes motor be rotated further, and Vo [i]=| TP [i]-P [i] |/(1.1 × T-T [i]), in formula
The pulse number that P [i] is sent out by the real electrical machinery position coder that current i-th Ziye records in real time, T [i] is
Current time；
F) when motor retreats, if during P [i] ＞ SlidePosL, motor brake, if during P [i] ＜ SlidePos,
Host computer given speed Vo [i] makes motor be rotated further, Vo [i]=| TP [i]-P [i] |/(1.1 × T-T [i]), formula
The pulse number that middle P [i] is sent out by the real electrical machinery position coder that current i-th Ziye records in real time, T [i]
For current time.
Multi-diaphragm collimator blade anti-collision control method the most according to claim 1, it is characterised in that: also wrap
Include and send, to host computer, the pulse that blade position encoder sends at interval of 50ms in step b)
Number, the step of motion between ipc monitor relative vane.
Multi-diaphragm collimator blade anti-collision control method the most according to claim 1, it is characterised in that: also wrap
Include in step c) host computer and apply, to the motor driving blade, the PWM arteries and veins that 4 dutycycles are 100%
E the most still it is more than at interval of 100ms by 1 | L-S | of upper computer detection after punching, if | L-S | is ＞ e,
Then repeat step c), until during | L-S | ＜ e, stopping detection.
Multi-diaphragm collimator blade anti-collision control method the most according to claim 1, it is characterised in that: described
T=50ms in step d).
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Families Citing this family (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CA2991083C (en) | 2015-09-10 | 2021-01-26 | Shanghai United Imaging Healthcare Co., Ltd. | Multi-leaf collimator and driving system |
| CN106512221B (en) * | 2015-09-14 | 2019-06-28 | 上海联影医疗科技有限公司 | Multi-diaphragm collimator, the drive system of multi-diaphragm collimator blade and driving method |
| CN105797283B (en) * | 2016-04-18 | 2018-12-18 | 苏州雷泰医疗科技有限公司 | A kind of grating blade controller and accelerator therapy device |
| US10166406B2 (en) * | 2017-02-24 | 2019-01-01 | Varian Medical Systems International Ag | Radiation treatment planning and delivery using collision free regions |
| CN108096720B (en) * | 2017-12-11 | 2020-06-02 | 上海联影医疗科技有限公司 | Multi-blade collimator initialization method and radiotherapy system |
| CN110187629B (en) * | 2019-05-31 | 2020-10-30 | 福建瑞达精工股份有限公司 | High-precision clock alarm starting point calibration method |
| CN110288932B (en) * | 2019-06-24 | 2022-11-11 | 深圳市福瑞达显示技术有限公司 | Anti-collision method of spliced fan screen based on FPGA and spliced fan screen |
| CN110548230B (en) * | 2019-09-11 | 2021-05-18 | 上海联影医疗科技股份有限公司 | Multi-leaf collimator control method, radiotherapy system and storage medium |
| WO2021179255A1 (en) * | 2020-03-12 | 2021-09-16 | Shanghai United Imaging Healthcare Co., Ltd. | Systems and methods for driving leaves of a multi-leaf collimator |
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| CN103371837A (en) * | 2012-04-27 | 2013-10-30 | Ge医疗系统环球技术有限公司 | Anti-collision method and device used for reciprocating motion device |
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| US8637841B2 (en) * | 2010-08-23 | 2014-01-28 | Varian Medical Systems, Inc. | Multi level multileaf collimators |
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| CN101246757A (en) * | 2007-08-23 | 2008-08-20 | 中国医学科学院肿瘤医院 | Generation method of dynamic independent collimating device collimation block movement path |
| CN101739034A (en) * | 2008-11-12 | 2010-06-16 | 深圳市海博科技有限公司 | Method for controlling movement of multi-diaphragm collimator |
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