CN109899711B - Lighting equipment and robotic cameras - Google Patents

Abstract

Embodiments of the present application provide a lighting device and a robot camera. Wherein, the lighting device includes at least three wing wing parts evenly arranged in space, a wing deployment mechanism, a light emitting part and a lens part located on each wing, the lens part covering the outside of the light emitting part; the wings; A deployment mechanism is connected with the wing members, and the wing deployment mechanism can cause the wing members to be deployed; when the lighting device is in an operating state, the wing members are in a deployed state. By applying the solutions provided by the embodiments of the present application, the shadow depth information in the target illumination area can be increased, thereby increasing the spatial information for objects in the target illumination area.

Description

Lighting equipment and robotic cameras

technical field

The present application relates to the field of lighting technology, and in particular, to a lighting device and a robot camera.

Background technique

The lighting device can provide illumination for the target illumination area. Lighting equipment can be widely used in various fields. Illumination devices can be used in enclosed spaces that require access from narrow gaps, for example, in vivo laparoscopes to illuminate focal areas in the abdominal cavity during minimally invasive surgery. When the lighting device is used in such an environment, the size of the lighting device is required not to be too large. Under the requirement of this size, the light-emitting components in the lighting device can usually only be compactly mounted on the main body, so as to reduce the volume of the lighting device.

Generally, the above-mentioned lighting device can enter the enclosed space through a narrow gap to provide illumination for the enclosed space. However, when this lighting device is used, the shadow depth information in the target illumination area is insufficient, which makes it impossible for human eyes to obtain sufficient spatial information for the object from the target illumination area.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present application is to provide a lighting device and a robot camera, so as to increase the shadow depth information in the target illumination area, so as to increase the spatial information for objects in the target illumination area.

In a first aspect, an embodiment of the present application provides a lighting device, comprising: at least three wing wing parts evenly arranged in space, a wing deployment mechanism, a light emitting part and a lens part on each wing, the The lens part is covered on the outside of the light-emitting part;

The wing deployment mechanism is connected with the wing member, and the wing deployment mechanism can cause the wing member to be deployed; when the lighting device is in an operating state, the wing member is in a deployed state.

Optionally, the lighting device further comprises: a tilting motion mechanism; the tilting motion mechanism can cause the lighting device to tilt.

Optionally, the lighting device further comprises: an anchoring part; the anchoring part is used for anchoring the lighting device at the target position.

Optionally, the lens component makes the light emitted by the light-emitting component map to the target irradiation area according to a specified mapping relationship;

The specified mapping relationship is: a mapping relationship in which the illumination uniformity of the target illumination area of the lighting device at a preset distance is not less than a preset uniformity threshold, and the illumination intensity is not less than a preset intensity threshold; the specified mapping The relationship is based on the refractive index of the lens part, the specified volume of the lens part, the size of the light-emitting part, the light intensity distribution of the light-emitting part, the relative position between the light-emitting part and the target irradiation area Sure.

得到，所述

为以下方程的解：Optionally, the specified mapping relationship is based on the surface gradient

get, the

is the solution of the following equation:

ζ＝{(ξ,η)|ξ²+η²≤1}，所述Ω_s为所述发光部件的光源域，所述ξ和η分别为所述发光部件所在投影平面的横坐标和纵坐标，所述I₀为所述发光部件中轴处的光强分布，所述BC为边界条件，所述E_t为预设的目标照射区域的照度分布函数，所述E_t为根据所述预设均匀度阈值和预设强度阈值确定。where ∈ is a constant coefficient,

ζ={(ξ,η)|ξ ² +η ² ≤1}, the Ω _s is the light source domain of the light-emitting component, and the ξ and η are the abscissa and ordinate of the projection plane where the light-emitting component is located, respectively Coordinates, the I ₀ is the light intensity distribution at the central axis of the light-emitting component, the BC is the boundary condition, the E _t is the preset illuminance distribution function of the target irradiation area, and the E _t is based on the The preset uniformity threshold and the preset intensity threshold are determined.

采用以下方式确定：Optionally, the specified gradient

Determined in the following way:

Taking the first initial value as the illuminance distribution function E _t of the target irradiation area;

Substitute the E _t into the equation

get the solution result u ^∈ ;

Determine the simulated illuminance distribution function of the target irradiation area according to the u ^∈

与所述E_t之间的差距是否小于预设值；judge the

Whether the gap with the E _t is less than the preset value;

If it is, then take the gradient with respect to the u ^∈ to get

将所述修正照度分布函数作为所述照度分布函数E_t的值，返回执行所述将所述E_t代入方程

的步骤。If not, calculate the corrected illuminance distribution function

Take the corrected illuminance distribution function as the value of the illuminance distribution function E _t , and return to execute the substituting the E _t into the equation

A step of.

Optionally, obtain the equation in the following way

The solution result of u ^∈ :

Taking the second initial value and the third initial value as the values of u ^∈ and ∈ respectively;

Substitute both the values of u ^∈ and ∈ into the equation

Carry out numerical discretization on the equation after substituting the value, and use a numerical solver to determine the solution u ^∈ of the equation after numerical discretization;

的步骤。Determine whether the value of ∈ is less than the preset minimum value, if so, take the determined solution u ^∈ as the solution result of the equation; if not, update the values of u ^∈ and ∈, and return to execute the The values of u ^∈ and ∈ are both substituted into the equation

A step of.

In a second aspect, the embodiments of the present application provide a robot camera, including: a camera module and the lighting device provided by the embodiments of the present application;

The camera module is fixed on the middle position of the wing member; when the wing member is in an unfolded state, the camera module can capture images, and when the wing member is in a folded state, the camera module inside the wing member.

Optionally, the range of the target illumination area of the lighting device at the preset distance is not less than the range of the image acquisition area of the camera module at the preset distance.

The lighting device and the robot camera provided by the embodiments of the present application include at least three wing parts evenly arranged in space, a wing deployment mechanism, a light emitting part and a lens part located on each wing, and the lens part covers the light emitting part On the outside of the luminaire, the wing unfolding mechanism is connected with the wing member, and the wing unfolding mechanism can promote the wing member to unfold; when the lighting device is in the working state, the wing member is in the unfolding state. Since the wing parts of the lighting device can be unfolded and folded, the size of the lighting device in the folded state can be smaller, and can enter the closed space from a narrow gap. When the lighting device is in working state, the wing parts can be unfolded, so that the light-emitting parts are evenly arranged in a larger space, and the light sources arranged in the larger space can increase the shadow depth information of the target illumination area, thereby increasing the target illumination Spatial information for objects in the region. Of course, implementing any product or method of the present application does not necessarily require achieving all of the advantages described above at the same time.

Description of drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the accompanying drawings that are required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative effort.

Fig. 1a and Fig. 1b are a schematic structural diagram of the lighting device provided in an embodiment of the present application in an unfolded state and a folded state, respectively;

FIG. 2a is another schematic structural diagram of the lighting device provided by the embodiment of the application;

Figure 2b and Figure 2c are two reference figures corresponding to Figure 2a;

FIG. 3 is a physical diagram of the lighting device provided by the embodiment of the present application;

4 is a schematic flowchart of a process for determining a surface gradient provided by an embodiment of the present application;

FIGS. 5 a to 5 d are all reference diagrams provided in the embodiments of the present application for determining a specified mapping relationship;

FIG. 6 is a schematic structural diagram of a robot camera provided by an embodiment of the present application;

FIG. 7 is another schematic structural diagram of a robot camera provided by an embodiment of the present application;

8 to 15 are all reference diagrams for evaluation and testing of the optical design of the lens provided by the embodiments of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, but not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present application.

In order to increase the shadow depth information in the target illumination area to increase the spatial information for objects in the target illumination area, embodiments of the present application provide a lighting device and a robot camera. The present application will be described in detail below through specific embodiments.

FIG. 1a is a schematic structural diagram of the lighting device provided in an embodiment of the application in an unfolded state, and FIG. 1b is a schematic structural diagram of the lighting device provided in an embodiment of the application in a folded state. In Figure 1a, the lighting device comprises: at least three wings of wing parts 101 uniformly arranged in space, a wing deployment mechanism 102, a light-emitting part 103 on each wing and a lens part 104, the lens part 104 The cover is outside the light-emitting member 103 . In Fig. 1b, the lighting device is in a folded state, and the three wings are folded to cover the light emitting part and the lens part inside.

The wing deployment mechanism is connected with the wing member, and the wing deployment mechanism can cause the wing member to be deployed; when the lighting device is in an operating state, the wing member is in a deployed state. Wherein, the wing deployment mechanism 102 may be an electric motor or other devices capable of providing driving force.

It can be seen from the above content that the wing member of the lighting device in this embodiment includes at least three wings that are evenly arranged in space, and the wing unfolding mechanism can promote the wing member to unfold. When the lighting device is in a working state, the wing member is in the unfolded state. . Since the wing parts of the lighting device can be unfolded and folded, the size of the lighting device in the folded state can be smaller, and can enter the closed space from a narrow gap. When the lighting device is in working state, the wing parts can be unfolded, so that the light-emitting parts are evenly arranged in a larger space, and the light sources arranged in the larger space can increase the shadow depth information of the target illumination area, thereby increasing the target illumination Spatial information for objects in the region.

In another embodiment of the present application, on the basis of Fig. 1a and Fig. 1b, the above-mentioned lighting device may further include: a tilting motion mechanism 105; the tilting motion mechanism 105 can cause the lighting device to tilt, as shown in Fig. 2a Show. Fig. 2b and Fig. 2c are two reference diagrams corresponding to Fig. 2a. Wherein, the tilting motion mechanism 105 may be a motor or other devices capable of providing driving force.

In this embodiment, the above-mentioned tilting motion mechanism 105 and the wing unfolding mechanism 102 can be stepping motors, for example, a step with a diameter of 4 mm, a length of 14.42 mm, and a planetary gear head of 125:1 (model ZWBMD004004-125) can be selected. into the motor. The stepper motor can provide 10mNm of torque in continuous operation. The worm and gear sets for the tilt kinematic mechanism and the wing deployment mechanism may have reduction ratios of 12:1 and 20:1, respectively.

In another embodiment of the present application, in Fig. 2a, the lighting device may further include: an anchoring part 106; the anchoring part 106 is used to anchor the lighting device at the target position. The anchoring member may be a magnetic device.

In another embodiment of the present application, in FIG. 2 a , the lighting device may further comprise two worm and gear sets 107 and 108 , the first worm and gear set 107 is used to connect the tilting motion mechanism 105 with the anchoring member 106 , the second worm and gear set 108 is used to connect the wing deployment mechanism 102 and the wing member 101 . When the wing member 51 includes three wings, the worm and gear set 562 may include one worm and three gears connected with the three wings, respectively.

Specifically, the first worm and the worm in the gear set 107 can be connected with the tilting motion mechanism 105 , and the first worm and the gear in the gear set 107 are connected with the anchoring member 106 . Driven by the tilting motion mechanism 105 , the first worm and the worm in the gear set 107 drive the gears to rotate, so that a certain angle is formed between the lighting device and the anchoring member 106 .

A second worm and gears in gear set 108 may be connected to wing deployment mechanism 102 and the second worm and gears of gear set 108 are connected to wing member 101 . Driven by the wing unfolding mechanism 102, the second worm and the worm in the gear set 108 drive the gears to rotate, so that the wing parts 101 are unfolded or folded.

FIG. 3 is a physical view of the lighting device in a folded state and an unfolded state. The physical diagram includes the anchoring part 106 and the lighting device. When the lighting device is in a folded state, the three wing parts 101 of the lighting device can be seen. When the lighting device is in the unfolded state, it can be seen that there are light-emitting parts 103 and lens parts 104 distributed on the three wing parts.

In order to improve the light efficiency and light uniformity of the target irradiation area, in another embodiment of the present application, the lens component can make the light emitted by the light emitting component 103 map the target irradiation area according to a specified mapping relationship. The mapping can also be understood as projection or illumination, that is, the lens component 104 can make the light emitted by the light-emitting component 103 project or illuminate the target illumination area according to a specified mapping relationship.

The specified mapping relationship is: a mapping relationship in which the illumination uniformity of the target illumination area of the lighting device at the preset distance is not less than the preset uniformity threshold, and the illumination intensity is not less than the preset intensity threshold; the specified mapping relationship is based on the lens component. The refractive index, the specified volume of the lens part, the size of the light-emitting part, the light intensity distribution of the light-emitting part, the relative position between the light-emitting part and the target illumination area are determined.

The light sent from the light-emitting component changes the light path after passing through the lens, and the light is irradiated on the target irradiation area according to the specified mapping relationship, so that the target irradiation area has a certain degree of uniformity and light intensity, providing reliable and stable lighting for minimally invasive surgery .

得到。具体的，可以根据表面梯度

构建透镜的表面形状函数，当发光部件发出的光经过该透镜时，从该透镜投射出的光与发光部件发出的光之间存在指定的映射关系。The above specified mapping relationship can be understood as a mapping relationship determined by the lens. The above specified mapping relationship can be based on the surface gradient

get. Specifically, according to the surface gradient

The surface shape function of the lens is constructed, and when the light emitted by the light-emitting component passes through the lens, there is a specified mapping relationship between the light projected from the lens and the light emitted by the light-emitting component.

可以理解为透镜的表面梯度。其中，

为以下方程的解：surface gradient

It can be understood as the surface gradient of the lens. in,

is the solution of the following equation:

E_s为发光部件的照度分布函数，ζ＝{(ξ,η)|ξ²+η²≤1}，ζ为发光部件照度的计算域。Ω_s为发光部件的光源域，ξ和η分别为发光部件所在投影平面ξ-η的横坐标和纵坐标。I₀为发光部件中轴处的光强分布，也就是发光部件极角为0度处的光强分布。BC为边界条件。E_t为预设的目标照射区域的照度分布函数，E_t为根据预设均匀度阈值和预设强度阈值确定。Among them, ∈ is a constant coefficient, which is used to assist in calculating the solution of the above equation.

_Es is the illuminance distribution function of the light-emitting component, ζ={(ξ,η)|ξ ² +η ² ≦1}, and ζ is the computational domain of the illuminance of the light-emitting component. Ω _s is the light source domain of the light-emitting component, and ξ and η are the abscissa and ordinate of the projection plane ξ-η where the light-emitting component is located, respectively. I ₀ is the light intensity distribution at the central axis of the light-emitting component, that is, the light intensity distribution where the polar angle of the light-emitting component is 0 degrees. BC is the boundary condition. E _t is a preset illuminance distribution function of the target irradiation area, and E _t is determined according to a preset uniformity threshold and a preset intensity threshold.

The above-mentioned surface gradient can be determined by the steps of the schematic flowchart shown in Figure 4:

Step S401: take the first initial value as the illuminance distribution function E _t of the target irradiation area;

Step S402: Substitute the E _t into the equation

get the solution result u ^∈ ;

Step S403: Determine the simulated illuminance distribution function of the target irradiation area according to the u ^∈

In this step, the surface gradient can be determined according to u ^∈ , the surface shape function of the lens can be determined according to the determined surface gradient, and the illuminance distribution function obtained after the light passes through the action of the surface shape function of the lens is determined according to the known illuminance distribution function of the light-emitting component. , as the target irradiation area

与所述E_t之间的差距是否小于预设值，如果是，则执行步骤S405，如果否，则执行步骤S406。Step S404: determine the

Whether the difference with the E _t is smaller than the preset value, if yes, go to step S405, if not, go to step S406.

与E_t之间的差距可以是

与E_t之间的差值，也可以是

与E_t之间的方差。预设值为预先设定的值。in,

The gap between E _t can be

difference from E _t , which can also be

Variance with E _t . The preset value is the preset value.

Step S405: Calculate the gradient of the u ^∈ to obtain

将所述修正照度分布函数作为所述照度分布函数E_t的值，返回执行步骤S402。Step S406: Calculate the corrected illuminance distribution function

Take the corrected illuminance distribution function as the value of the illuminance distribution function E _t , and return to step S402.

In a specific implementation manner, step S402 may be performed in the following manner:

Step 1: Take the second initial value and the third initial value as the values of u ^∈ and ∈, respectively.

Wherein, the second initial value is the solution of the guessed equation. ∈ can take values in a preset sequence of gradually decreasing constants, such as 1, 10 ⁻¹ , 10 ⁻² , and so on.

Step 2: Substitute both the values of u ^∈ and ∈ into the equation

Step 3: Carry out numerical discretization on the equation after substituting the value, and use a numerical solver to determine the solution u ^∈ of the equation after numerical discretization;

Among them, numerical discretization and numerical solver are common methods for solving equations, which will not be described in detail here.

Step 4: Determine whether the value of ∈ is less than the preset minimum value, if so, take the determined solution u ^∈ as the solution result of the equation; if not, update the values of u ^∈ and ∈, and return to step 2 .

When updating u ^∈ , the solution u ^∈ determined in step 3 can be used as the updated u ^∈ . The value of ∈ in the constant sequence can be determined according to the deviation direction between the solved u ^∈ and the substituted u ^∈ .

The derivation process of the above formula is described in detail below.

将辐照度E_s转变为E_t，其中ζ＝(ξ,η)和

是源域Ω_s和目标域Ω_t约束的笛卡尔坐标。上述等式被认为是L² Monge-Kantorovich问题的特殊情况。假设没有传输能量损失，φ应满足Let E _s (ξ, η) and E _t (x, y) denote the irradiance distribution of the light-emitting component, ie, the LED source, and the prescribed target radiation distribution, respectively. As shown in Figure 5a, the goal of this application is to find the ray mapping function

Convert the irradiance _Es to Et, where _ζ =(ξ,η) and

are the Cartesian coordinates constrained by the source domain Ω _s and the target domain Ω _t . The above equation is considered a special case of the L2 Monge ^- Kantorovich problem. Assuming no transmission energy loss, φ should satisfy

式(1)应表示为According to the mapping

Formula (1) should be expressed as

L2Monge-Kantorovich问题可以被表征为凸面的梯度

代替式(2)中的

我们可以看到u是标准Monge-Ampere方程的解：Brenier's theorem states that there is a unique solution to the L2 Monge-Kantorovich problem

The L2Monge-Kantorovich problem can be characterized as the gradient of a convex surface

Substitute in formula (2)

We can see that u is the solution of the standard Monge-Ampere equation:

It is observed that weak solutions of low-order nonlinear PDEs can be approximated by sequences of higher-order quasi-linear PDEs. To approximate the solution of the standard Monge-Ampere equation as a second-order nonlinear partial differential equation, the biharmonic operator with fourth-order partial derivatives is a good choice.

The approximate solution of equation (3) can thus be calculated from:

是弱解。Ω_s的内部点应满足式(4)。Ω_s的边界

上的点应映射到Ω_t的边界

上。where ∈>0, if the limit exists,

is a weak solution. The interior points of Ω _s should satisfy equation (4). Boundary of Ω _s

The points on should map to the boundary of Ω _t

superior.

Neumann边界条件可以表达为according to

The Neumann boundary condition can be expressed as

的数学表达式。结合式(4)和式(5)，用于设计自由透镜的射线映射可以从以下准线性PDE和Neumann边界条件计算where f is

mathematical expression. Combining equations (4) and (5), the ray map for designing free lenses can be calculated from the following quasilinear PDE and Neumann boundary conditions

需要有效的数值方法，在本节详细介绍。上述步骤1～步骤4给出了求解式(6)的计算步骤。所提出的数值方法的主要思想是通过在每个迭代中更新∈来迭代近似u^∈。具体而言，将∈设定为逐渐减小的常数值的序列，例如1，10^-1，10^-2等。在每次迭代中，初始u^∈首先由最后一次迭代的输出u^∈提供或手动给出(在第一次迭代中)。迭代次数取决于序列中∈的个数。我们可以用∈＝1开始迭代，得到u^∈的初始近似，这就是式(3)的解。当∈→0⁺，式(4)等于式(3)。但这并不意味着我们在迭代过程中将∈定为0时可以找到最佳近似解u^∈。Calculate the ray map from equation (6)

Efficient numerical methods are required, which are detailed in this section. The above steps 1 to 4 give the calculation steps for solving equation (6). The main idea of the proposed numerical method is to iteratively approximate u ^∈ by updating ∈ at each iteration. Specifically, ∈ is set to be a sequence of gradually decreasing constant values, such as 1, 10 ⁻¹ , 10 ⁻² , and so on. In each iteration, the initial u ^∈ is first provided by the output u ^∈ of the last iteration or manually (in the first iteration). The number of iterations depends on the number of ∈ in the sequence. We can start the iteration with ∈ = 1 and get an initial approximation of u ^∈ , which is the solution of Eq. (3). When ∈→0 ⁺ , equation (4) is equal to equation (3). But this does not mean that we can find the best approximate solution u ^∈ when we set ∈ to 0 in the iterative process.

由下式约束：error

Constrained by:

时，能够得到最小的全局误差。where u ^∈ indicates that equation (6) has a numerical solution of grid size h. The final value of ∈ in Eq. (6) is related to h, which is used to achieve the optimal convergence speed and minimize the error. This relationship depends on the norm used. According to the experimental data obtained in this application, when ∈=h,

, the smallest global error can be obtained.

To numerically discretize equation (6), the quasi-linear partial differential equation and boundary condition BC are re-expressed as:

采用具有二阶校正误差的前向/后向有限差分方法。式(8)中的双调和项的离散化Δ²u^∈可以由十三点模板表述The discretization of the first-order and second-order partial derivatives in Eq. (8) adopts the central finite difference method in the inner region of Ω _s , and for the boundary region

A forward/backward finite-difference method with second-order correction errors is employed. The discretization Δ ² u ^∈ of the biharmonic term in Eq. (8) can be expressed by a thirteen-point template

的中心的示例。在这种情况下，

和

在源区域Ω_s之外。未定义的

和

的近似可以通过以下公式计算：Here, (ξ _i , η _j ) is abbreviated as (i, j). However, when the critical points are discretized by using the thirteen-point template in Eq. (9), undefined points are introduced. Figure 5b shows the thirteen point template located in the critical region

example of the center. in this case,

and

outside the source region Ω _s . undefined

and

The approximation of can be calculated by the following formula:

表示的网格中临界值；h是两个方向ξ和η的网格大小；

是Ω_s上的一阶偏微分，其可由式(8)中的边界条件确定。式(8)的数值离散化得到一组非线性方程，可以表示为以下形式in,

represents the critical value in the grid; h is the grid size in both directions ξ and η;

is the first-order partial differential over Ω _s , which can be determined by the boundary conditions in Eq. (8). The numerical discretization of Eq. (8) obtains a set of nonlinear equations, which can be expressed in the following form

F(U ^∈ )=0 (11)

where U ^∈ represents a vector of variables u ^∈ . Select Newton's method as the numerical solver to compute the output u ^∈ . Then, compare ∈ with ∈ _min = h in the current iteration, and if ∈>h, update the initial values u ^∈ and ∈ with the calculated U ^∈ and smaller ∈. If ∈ ≤ h, the gradient of the numerical solution U ^∈ in the current iteration is taken as the final surface gradient.

The ray mapping method proposed above requires the use of the irradiance distribution E _s (ξ,η) of the light source LED. However, high-power LEDs, which are generally considered to be Lambertian sources, are defined by the luminous intensity distribution in hemispherical space by I=I ₀ cosθ(lmsr ⁻¹ ), where θ represents the polar angle of the ray and I ₀ represents θ=0° luminous intensity. This embodiment applies the stereo projection method to convert the light intensity of the light source into the irradiance distribution defined on the plane. The main idea of this method is to map the light energy along the emission directions SP=x _u , _yu , _zu to the projected coordinates ζ=(ξ, η) on the ξ-η plane, as shown in Fig. 5c. The final form of the irradiance _Es on the ξ-η plane is

Wherein, ξ ² +η ² ≤1. For grid points ξ ² +η ² ≥ 1, we define E _s (ξ,η)=0.

表示来自光源的单位入射光线矢量，其中

和

是(ξ_i,η_j)的函数。本实施例采用易于实施的表面构建方法设计光源的初始光学表面。该方法的主要思想是首先构建一个具有点p_1,1,…,p_1,n的序列的曲线，如图5d(1)-①所示。然后生成的曲线用于计算沿图5d(1)-②中的方向的表面点。Based on the calculated ray maps, each pair of coordinates (ξ _i , η _j ) in ∑ _L {x _L , y _L , z _L } space can be mapped to the target plane ∑ _G {x _G , y G , y _G , A point in z _G } space T′ _i,j =(x′ _i ,y′ _j ,z′(x _i ,y _j )), where i and j represent the discretization indices of the light source. According to the rotation matrix R and translation vector T between Σ _G and Σ _L , T′ _i,j can be represented by T _i,j in Σ _L , as shown in Fig. 5d(2). Depend on

represents the unit incident ray vector from the light source, where

and

is a function of (ξ _i , η _j ). This embodiment uses an easy-to-implement surface construction method to design the initial optical surface of the light source. The main idea of this method is to first construct a curve with a sequence of points p _1,1 ,...,p _1,n , as shown in Fig. 5d(1)-①. The generated curves are then used to calculate surface points along the directions in Fig. 5d(1)-②.

As shown in Figure 5d(1), define O _i,j as the unit outgoing ray from the optical surface, and formulate it as:

where p _i,j represents the point to be constructed on the surface. In Fig. 5d(1)-①, considering the desired lens volume, the initial point p _1,1 can be manually selected according to the required lens volume. Therefore, O _1,1 is calculated using equation (13). The normal vector at p _i,j can be calculated by Snell's law:

where n ₀ represents the refractive index of the medium surrounding the lens and n ₁ represents the refractive index of the lens. The coordinates of the next point p _1,2 on the curve are calculated as the intersection between the ray I _1,2 and the plane defined by p _1,1 and N _1,2 . After obtaining the points on the first curve in Fig. 5d(1)-①, the points of the curve in direction ② can be calculated by using the points on the first curve as initial points.

After the above method is used to construct a freeform surface with the desired lens volume, it cannot guarantee that the normal vector N _{i,j computed at pi,j for} pi _,j and its neighbors pi ₊ due to accumulated errors The vector between _1,j , p _i,j+1 is constant, as shown in Figure 5d(2). In order to solve this problem and improve the lighting performance, the present application introduces an iterative optimization technique to correct the constructed initial surface to better fit the normal vector. In theory, if the surface mesh is small enough, the surface point pi _,j and the normal vector N _i,j at that point should satisfy the following constraints:

(p _i+1,j -p _i,j )·N _i,j =0 (15)

(pi _,j+1 - _pi,j )·N _i,j =0 (16)

Suppose we represent the plane with N points. Replace p _i,j in equations (15) and (16) with ρ _i,j I _i,j , and get N constraints F ₁ ,...F _N :

F _k (ρ)=||(ρ _{i+1, j} I _{i+1, j-} ρ _{i, j} I _{i, j} )·N _{i, j} ||+||(ρ _{i, j+1} I _{i , j+1} −ρ _{i, j} I _{i, j} )·N _ij ||=0, (17)

where k=1, 2, . . . , N, ρ _i,j represents the distance between S and the surface point pi _,j . The nonlinear least squares method is used to minimize F ₁ (ρ) ² +...+F _N (ρ) ² with ρ _i,j as variables. The updated normal vector N _i,j is calculated according to Eq. (14) by using ρ and the ray map optimized by the current iteration. Iterates to compute new ρ until the computed surface points satisfy the convergence condition ‖ρ _t - ρ _t-1 ‖<δ, where t represents the current iteration number and δ is the stopping condition. Finally, optical surfaces can be represented by using free surface points with Non-Uniform Rational Basis Splines (NURBS).

表示应用自由透镜后照度分布的模拟结果。下一次迭代后被修正的照度分布

可以定义为Due to the point light source assumption, with extended size LEDs, illumination uniformity is reduced, especially when designing small volume optical lenses. This problem can be mitigated by employing feedback correction methods. Use E _t (x, y) to represent the required illuminance distribution of the target area,

Represents the simulation result of the illuminance distribution after applying the free lens. Corrected illuminance distribution after the next iteration

can be defined as

At each iteration it is checked whether the lighting performance achieves a satisfactory uniformity of illumination. If so, the free optical lens design is complete. Otherwise, the next iteration is performed to correct the surface of the free lens.

FIG. 6 is a schematic structural diagram of a robot camera according to an embodiment of the present application. The robot camera includes: a camera module 601 and any lighting device 602 provided in the embodiment of the present application;

The camera module is fixed on the middle position of the wing member; when the wing member is in an unfolded state, the camera module can capture images, and when the wing member is in a folded state, the camera module is in the inside the wing member. The camera module 601 may include sub-components such as imaging sensors and lenses.

In the related art, the coaxial configuration of the imaging sensor and the light source will lead to lack of shadow depth cues in the output two-dimensional image, which will lead to insufficient depth information and position information in the image collected by the camera module. The coaxial configuration is a configuration in which the central axis of the imaging sensor and the central axis of the light source are parallel.

Fixing the camera module in the middle of the wing member or at other positions allows the image sensor and light source to be in a non-coaxial configuration. The non-coaxial configuration is a configuration in which the central axis of the imaging sensor and the central axis of the light source are not parallel. This non-coaxial configuration enables the camera module to collect more shadow depth information, thereby enabling the robot camera in this embodiment to collect images with better depth information.

To sum up, in this embodiment, the lighting device includes a wing member, the wing member includes at least three wings that are uniformly arranged in space, and the light-emitting member and the lens member are located on each wing. In this way, no matter where the camera module is fixed on the lighting device, the non-axial configuration of the imaging sensor and the light source can be ensured, so that the shadow depth information in the image can be increased.

FIG. 7 is a schematic diagram of a specific structure of a robot camera according to an embodiment of the present application. This figure includes an anchor member 106, a first worm and gear set 107 connected to the tilt motion mechanism 105, a second worm and gear set 107 connected to the wing deployment mechanism, the wing member 101, and the Light emitting part 103 and lens part 104 . The camera module 601 is located in the middle of the wing member.

In this embodiment, the light emitted by the light-emitting component is bent after passing through the lens component, and finally irradiates on the target irradiation area. In a specific embodiment, the range of the target illumination area at the preset distance of the lighting device is not less than the range of the image capture area at the preset distance by the camera module. In this way, all the images collected by the camera module can be included in the target irradiation area, so that the imaging quality of the images is better.

In the present application, Applicants evaluate the performance of a lens design method in laparoscopy. Figures 8(a) and (b) show on-axis and off-axis experiments, respectively, which were conducted to investigate the effectiveness of optical design methods in different application scenarios using optical design software. In this application, polymethyl methacrylate (PMMA) with a refractive index of 1.49 is used as the lens material, and a Nichia NCSWE17A LED with a luminous flux of 118lm is used as the light source. In order to verify that the method provided by the embodiments of the present application is flexible and can design free optical lenses for target irradiation areas with different patterns, the applicant sets target irradiation areas with circular patterns and square patterns in the on-axis illumination test. See Table 1 for detailed specifications.

Table 1 Evaluation specification for optical design method of free-form surface

Calculation of raymaps. First, the light intensity distribution of the LED (Fig. 8(c)) was converted into a normalized illuminance distribution (Fig. 8(d)). The computational fields of ξ∈[-1,1], η∈[-1,1] of LEDs are discretized by an 81×81 grid. According to the ray mapping algorithm, the grid size h = 0.025 determines the minimum value of ε to be 0.025. This application chooses the sequence of ε taking 1, 0.5, 0.025 to approximate the numerical solution of ray mapping. In order to verify the effectiveness of the method for generating the ray mapping relationship in this embodiment, the intermediate ray mapping result calculated by using ε to take 1, 0.5, and 0.025 is demonstrated. The ray mapping relationship calculated with ε=0.025 was used to generate the initial surface of the free optical lens of the LED.

FIG. 8 is a simulation device for evaluating the free optical design method. (a) On-axis test: The axis of the LED is coincident with the axis of the target illumination area, and the target illumination area is circular and square in the test; (b) Off-axis test: The axis of the LED and the axis of the target illumination area are offset between Δd=5mm, 10mm and 15mm. In this test, only the circular target illumination area is used; (3) the LED light intensity distribution is obtained from the LED data sheet; (d) the LED light intensity distribution is converted using this method.

Fig. 9 shows the on-axis ray mapping relationship calculated respectively for the circular and square target irradiation areas, where ε=1, 0.5, 0.025, and an 81×81 grid is used. For clear visualization purposes, a 61×61 grid is inserted in this figure.

Figure 10 shows the convergence rate of the ray map relation generation method. The characteristics of the convergence rate are expressed by the residual value of ||F|| ₂ in formula (11) and the number of iterations. The remainder of formula (11) ||F|| ₂ is in millimeters. Considering that the freeform optical lens can be at the sub-micron scale ( ^10-4 mm), the convergence threshold can be conservatively set at the nano-scale ( ^10-7 mm). In all experiments, ||F|| ₂ can reach a value of 10 ⁻⁷ after 10 iterations. In Figure 10, (a)-(c) and (d)-(f) are the convergence rates in the circular and square regions when ε is 1, 0.5 and 0.025, respectively.

On-axis testing of freeform optical lens designs. Figure 10(a) shows the simulated setup for axial testing of the freeform optical lens design. The on-axis test was carried out using a circular target irradiation area with a radius R of 80mm and a square target irradiation area with a side length 2R of 160mm. The illumination distance from the LED to the center of the target irradiation area was set to D=100 mm. Figures 11(a) and (b) show the designed lens profile with marked dimensions. Figures 13(c) and (d) show the simulated illuminance distribution on the target illumination area. Considering the Fresnel loss, the optical efficiencies of the free-form lens are 88.3% and 90.5%, respectively. Illumination uniformity (Uniformity) can be calculated by formula (19)

where σ and μ are the standard deviation and mean of the collected illuminance data. Table 2 details the optical properties tested on-axis.

Table 2 Optical properties of on-axis tests

Figure 11 is an on-axis freeform lens design for two different illumination patterns. (a) and (b) show the lens profiles for circular and square regions, respectively. (c) and (d) show the illumination uniformity performed on the target plane for (a) and (b), respectively.

Off-axis testing of freeform optical lens designs. Figure 8(b) illustrates the simulated setup for off-axis testing. The illumination area was set as a circular area with a radius R of 80mm. The distance from the LED to the target plane is set to D=100mm. Axial offset Δd = 5mm, 10mm and 15mm were introduced to evaluate the best performance when the LED5s axis and the target illumination area S5s were not aligned. To construct freeform optical surfaces in this more general case, a transformation matrix is required to transform the ray map from global coordinates to the local coordinates of the LED. Figure 12 shows the designed lens profile and simulated illuminance distribution results for each case. Due to the axis offset, the optical lens is no longer symmetrical. Therefore, embodiments of the present application provide front and side views of the lens, as shown in Figures 12(a), (d) and (g). Figure 12(b), (e) and (h) show the simulated illuminance distribution of the illuminated area of the circular target. Considering the Fresnel loss, the optical efficiencies of the free-form lens are 88.06%, 87.74% and 88.15%, respectively. Figures 12(c), (f) and (i) show the illuminance uniformity along the horizontal and vertical directions in the illuminated area. Table 3 summarizes the optical performance of the off-axis test.

Table 3 Optical properties of off-axis tests

Final design of the LED free optical lens. Referring to the configuration of the lighting device provided in FIG. 13 , the lens mounting position L on the wing was set to 20.5 mm. For the extended mode, the opening angle of the wing is set to β=80°. In the design, a lens volume with a maximum radial length pmax of 5.4 mm is set to ensure that three lenses can fit into the robotic camera. The initial illumination distance D was set to 100 mm. The radius of the target circular area R is set to 80 mm. Table 4 summarizes the specifications of the free optical lens design for laparoscopic illuminators.

Table 4 Specifications of Lighting Equipment Setup

Figure 13 shows a three-dimensional (3D) design of a laparoscopic illumination device. Figure 13(a) shows three views of the freeform surface. Figure 13(b) shows the compactness of the lens satisfying the lens volume constraints. Figure 13(c) shows the integration of lenses and LEDs in one wing. Figure 13(d) shows the 3D structure of the assembled laparoscopic illumination device.

The lighting performance of the target illuminated area. The performance of the developed lighting device was evaluated according to the simulation settings in Table 4. Due to the symmetrical arrangement of the three wings, a single LED is energized first, emitting light through its free-form lens. Fig. 14(a) shows the illuminance distribution on the target irradiation area. Taking into account the Fresnel loss, the optical efficiency of the designed freeform lens is 89.45%, which means that each 105.55lm of light in the total 118 lumens of light flux is successfully projected to the desired target illumination area. The average illuminance provided by a single LED is 5473.8 lx. According to formula (19), the horizontal and vertical illuminance uniformity are 95.87% and 94.78%, respectively, as shown in Fig. 14(b).

Figure 14(c) shows the illuminance distribution on the target illuminated area when all LEDs are powered on. In this case, the total luminous flux provided by the lighting device is 354 lumens, and the total luminous flux falling on the target illuminated area is 316.58 lumens, with an optical efficiency of 89.43%. The average illuminance of the target illuminated area is 12,441lx. Figure 14(d) shows that the illuminance units in the horizontal and vertical directions are 96.33% and 96.79%, respectively. Figure 14(e) shows the illuminance distribution of the target irradiated area with a 3D profile. The evaluation results of lighting performance are summarized in Table 6. It can be clearly seen that the laparoscopic lighting device developed in the embodiment of the present application meets all the design requirements in Table 6.

Table 6 Design requirements for laparoscopic lighting equipment

Focus the beam. In MIS, after the intra-abdominal laparoscopic system is inserted into the abdominal cavity, the distance D between the camera and the target surgical field may be less than 100 mm. While the wings of the luminaire can still provide good illumination in the area at an angle β of 80 degrees, the illuminance uniformity is reduced and more energy is wasted outside the FOV.

The in-vivo laparoscopic lighting device proposed in the embodiment of the present application has a refocusing function. By adjusting the angle of the wing, the target irradiation area can be uniformly illuminated when the distance from the camera module to the target changes, thereby controlling the light beam. In Fig. 15(a), the desired target irradiation area D=60 mm can be set. When the angle β of the wing is set to 80°, the illuminated area is covered by a yellow line. This β value is most suitable for D=100mm. To refocus the light in the target illuminated area at D=60mm, reduce the span angle from β to β-Δβ, the angle θ between the green and yellow dashed arrows can be determined by using the angle θ between the green dashed arrow and the yellow dashed arrow. value. From the geometry of this setup, θ is calculated to be 6°. Similarly, in order to illuminate the target illumination area of D=80mm, the angle of the wing should be reduced by θ=3° from the initial angle β=80°.

Figures 15(b)-(e) show the illuminance distribution of the beam passing through the refocusing target plane at D=60mm and D=80mm. In the case of FIGS. 15( b ) and ( c ), it is set to 74°. The average illuminance of a circular area with a radius R of 48mm is calculated to be 45823 lx. In the case of considering Fresnel loss, the optical efficiency is about 92%. The illuminance uniformity in the horizontal and vertical directions is 98.29% and 98.22%, respectively. Whereas in the case of FIGS. 15( d ) and ( e ), β was set to 77° to irradiate the target irradiation area of D=80 mm. The average illuminance for a circular area with a radius R of 64 mm is calculated to be 24172 lx. Taking into account the Fresnel loss, the optical efficiency is 90.9%. The horizontal and vertical illuminance uniformity are 95.37% and 95.98%, respectively. The illumination performance of the refocused beams is summarized in Table 7.

Table 7 Lighting performance for light refocusing test

It should be noted that, in this document, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any relationship between these entities or operations. any such actual relationship or sequence exists. Moreover, the terms "comprising", "comprising" or any other variation are intended to encompass a non-exclusive inclusion such that a process, method, article or device comprising a list of elements includes not only those elements, but also not expressly listed Other elements, or elements that are inherent to such a process, method, article or apparatus. Without further limitation, an element qualified by the phrase "comprising a..." does not preclude the presence of additional identical elements in a process, method, article or apparatus that includes the element.

Each embodiment in this specification is described in a related manner, and the same and similar parts between the various embodiments may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and for related parts, please refer to the partial descriptions of the method embodiments.

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application are included in the protection scope of this application.

Claims (7)

1. A lighting device, characterized in that it comprises: wing parts of at least three wings evenly arranged in space, a wing deployment mechanism, a light-emitting part and a lens part located on each wing, the lens parts being covered in the outer side of the light-emitting component; The wing deployment mechanism is connected with the wing member, and the wing deployment mechanism can cause the wing member to unfold; when the lighting device is in an operating state, the wing member is in a deployed state; The surface gradient of the surface shape of the lens component is a surface gradient

The lens component makes the light emitted by the light-emitting component map to the target irradiation area according to a specified mapping relationship; the specified mapping relationship is: the illumination uniformity of the target irradiation area at a preset distance of the lighting device is not less than a predetermined value. Set a uniformity threshold and a mapping relationship in which the light intensity is not less than a preset intensity threshold; the specified mapping relationship is based on the refractive index of the lens component, the specified volume of the lens component, the size of the light-emitting component, the determining the light intensity distribution of the light-emitting component and the relative position between the light-emitting component and the target irradiation area; The specified mapping relationship is based on the surface gradient

get, the

is the solution of the following equation:

Wherein, the ε is a constant coefficient, E _s is the illuminance distribution function of the light-emitting component,

ζ is the calculation domain of the illuminance of the light-emitting component, ζ={(ξ, η)|ξ ² +η ² ≤1}, the Ω _s is the light source domain of the light-emitting component, and the ξ and η are the light-emitting The abscissa and ordinate of the projection plane where the component is located, the I ₀ is the light intensity distribution at the central axis of the light-emitting component, the BC is the boundary condition, and the E _t is the preset illuminance distribution function of the target irradiation area , the E _t is determined according to the preset uniformity threshold and the preset intensity threshold. 2 . The lighting device according to claim 1 , wherein the lighting device further comprises: a tilting motion mechanism; the tilting motion mechanism can cause the lighting device to tilt. 3 . 3. The lighting device according to claim 2, characterized in that, the lighting device further comprises: an anchoring part; the anchoring part is used for anchoring the lighting device at the target position. 4. The lighting device of claim 1, wherein the surface gradient

Determined in the following way: Taking the first initial value as the illuminance distribution function E _t of the target irradiation area; Substitute the E _t into the equation

get the solution result u ^∈ ; Determine the simulated illuminance distribution function of the target irradiation area according to the u ^∈

judge the

Whether the gap with the E _t is less than the preset value; If it is, then take the gradient with respect to the u ^∈ to get

If not, calculate the corrected illuminance distribution function

Take the corrected illuminance distribution function as the value of the illuminance distribution function E _t , and return to execute the substituting the E _t into the equation

A step of. 5. The lighting device according to claim 4, wherein the equation is obtained in the following manner

The solution result of u ^∈ : Taking the second initial value and the third initial value as the values of u ^∈ and ∈ respectively; Substitute both the values of u ^∈ and ∈ into the equation

Carry out numerical discretization on the equation after substituting the value, and use a numerical solver to determine the solution u ^∈ of the equation after numerical discretization; Determine whether the value of ∈ is less than the preset minimum value, if so, take the determined solution u ^∈ as the solution result of the equation; if not, update the values of u ^∈ and ∈, and return to execute the The values of u ^∈ and ∈ are both substituted into the equation

A step of. 6. A robot camera, comprising: a camera module and the lighting device according to any one of claims 1 to 5; The camera module is fixed on the middle position of the wing member; when the wing member is in an unfolded state, the camera module can capture images, and when the wing member is in a folded state, the camera module inside the wing member. 7 . The robot camera according to claim 6 , wherein the range of the target illumination area of the lighting device at the preset distance is not less than the size of the image acquisition area of the camera module at the preset distance. 8 . scope.

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