JP5315488B2 - Liquid transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a liquid conveyance apparatus capable of conveying liquid without spilling liquid. <P>SOLUTION: The liquid conveyance apparatus 10 includes: a spoon 14 which stores liquid and convey the liquid from a start point O to a finish point P on X-Y-Z orthogonal coordinates; arms 26, 30, 34 which support the spoon 14 and move the spoon 14; a drive unit which drives the arms 26, 30, 34; and a control unit 18 which controls the drive unit so that an X-Y coordinate component C<SB>X-Y</SB>in a conveyance track C of a storage portion 14 becomes straight. The control unit 18 controls the drive unit so that an X-Y coordinate component in a conveyance speed curve of the spoon 14 comprises an acceleration stage, a constant velocity stage, and a deceleration stage. An acceleration curve S and a deceleration curve T are set so that a working force working on liquid during acceleration or deceleration is smaller than the surface tension of liquid filling the spoon 14. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a liquid transport apparatus, and more particularly to a liquid transport apparatus capable of transporting liquid stored in a storage section without overflowing.

  For example, in medical and welfare settings, research is being actively conducted on an assist device that reduces the burden on a caregiver and an independence support robot for the purpose of supporting the independence of a care recipient. In particular, since meal is an indispensable task every day, both the caregiver and the cared person have a heavy burden, and various devices that support meals have been researched and developed (for example, see Patent Document 1).

  However, the meal support apparatuses proposed so far have limited items that can be eaten for structural and functional reasons, and may take a long time to complete the meal. In particular, it has been difficult to quickly transport liquid foods such as soup, miso soup and porridge to the care recipient's mouth without overflowing.

On the other hand, many studies have been made on liquid transport control that enables liquid transport at high speed while suppressing vibration of the liquid (see the following document). Therefore, for example, if the vibration control such as the hybrid shaping method is applied to the meal support apparatus described above, it may be possible to transport liquid food without overflowing.
JP-A-11-253504 JT Feddema, et al., “Control for Slosh-Free Motion of an Open Container, IEEE Control Systems Magazine, Vol. 17 (1997), pp. 29-36 K. Yano and K. Terashima, “Robust Liquid Container Transfer Control for Complete Sloshing Suppression, IEEE, Transaction on Control Systems Technology, Vol. 9, no. 3 (2001), pp. 483-493 K. Yano, S. Higashikawa and K. Terashima, “Motion Control of Liquid container Considering an Inclined Transfer Path, IFAC Journal of Control Engineering Practice, Vol. 10, no. 4 (2002), pp. 465-472 K. Yano and K. Terashima, “Sloshing Suppression Control of Liquid Transfer Systems Considering 3D Transfer Path, IEEE / ASME Transactions on Mechatronics, Vol. 10, no.l (2005), pp.8-16

  However, the hybrid shaping method is effective when the container (container) contains liquid with a margin, but if the liquid fills the container, slight fluctuations in the liquid level during acceleration / deceleration The liquid may overflow from the container due to (displacement). In particular, in the case of small containers such as spoons, the surface tension during transport is greatly affected, and the vibration phenomenon of the liquid level cannot be accurately grasped by the conventional vibration suppression control method, so that the liquid does not overflow. It seems impossible to do.

  In view of the above-described problems inherent in the prior art, the present invention has been proposed to suitably solve these problems, and provides a liquid transport apparatus that can transport the liquid stored in the storage section without overflowing. The purpose is to do.

In order to solve the above-described problems and achieve the desired purpose suitably, the liquid transport device according to the present invention includes:
A storage unit for storing the liquid and transporting the liquid from the start point to the end point on the XYZ orthogonal coordinates;
An arm for supporting the housing and moving the housing;
A drive unit for driving the arm unit;
A control unit that controls the drive unit so that the XY coordinate component in the transport path of the storage unit is a straight line;
The control unit includes an acceleration stage in which the XY coordinate component in the transport speed curve of the storage section accelerates the storage section with a predetermined acceleration curve, and a constant speed stage in which the storage section is moved at a speed at the end of acceleration. Controlling the drive unit to be configured with a deceleration stage that decelerates the accommodating unit with a predetermined deceleration curve,
The acceleration curve and the deceleration curve are set such that the acting force acting on the liquid during acceleration or deceleration is smaller than the surface tension of the liquid filled in the container.
According to the first aspect of the present invention, the acceleration curve and the deceleration curve of the storage portion at the time of transport are set so that the acting force acting on the liquid is smaller than the surface tension of the liquid, so that the liquid does not overflow. Can be transported to the end point. In addition, the XY coordinate component of the transfer speed curve has a constant speed stage that does not cause an action force on the liquid, so it is not necessary to obtain acceleration / deceleration curves for all transfer trajectories, and the amount of calculation is reduced. Can do. Moreover, since the XY coordinate component of the transport trajectory is controlled to be a straight line, the liquid transport problem in the three-dimensional space can be simplified as a liquid linear transport control problem, and the acceleration / deceleration curve can be derived. The amount of calculation required can be further suppressed.

In the liquid transfer device according to the second aspect, the deceleration curve is set to a curve obtained by inverting the acceleration curve on the time axis.
According to the invention of claim 2, since the deceleration curve is set to a curve obtained by inverting the acceleration curve on the time axis, it is not necessary to obtain the deceleration curve by calculation, and the calculation amount can be halved.

In the liquid transfer device according to a third aspect, the parameter of the acceleration curve is obtained by searching with a genetic algorithm under a constraint condition in which the acting force on the liquid during acceleration is smaller than the surface tension.
According to the invention of claim 3, since the acceleration curve is defined by the parameters obtained by searching with a genetic algorithm, the amount of calculation required for deriving the acceleration curve can be suppressed.

  According to the liquid transport device of the present invention, the liquid stored in the storage unit can be transported without overflowing.

  Next, a preferred embodiment of the liquid transport device according to the present invention will be described below with reference to the accompanying drawings. In addition, in an Example, suppose that the liquid conveyance apparatus which conveys liquids, such as water and soup with a spoon, and supports a user's meal is demonstrated.

  As shown in FIG. 1, the liquid transport device 10 according to the embodiment includes a six-axis manipulator 12, and an attachment portion 16 in which a handle portion 14 a of a spoon (accommodating portion) 14 is detachably attached to the tip of the manipulator 12. And a control unit 18 for controlling the operation of the manipulator 12. Further, the liquid transport device 10 includes an operation switch 20 that is operated by a user, and the operation of the manipulator 12 is turned on and off by operating the operation switch 20. Note that the root of the manipulator 12 is fixed by a fixing unit 22 to a table 40 used by the user for eating.

  The manipulator 12 includes a first joint part 24, a first arm part 26, a second joint part 28, a second arm part 30, a third joint part 32, a third arm part 34, and a fourth arm in order from the fixed part 22 side. The joint part 36 and the front-end | tip part 38 are provided, and the 1st-6th motor (drive part) which is not shown in figure is provided in each rotation site | part. The controller 18 controls the driving of the first to sixth motors, so that the first to third arm portions 26, 30, and 34 are rotated to realize a highly flexible movement of the manipulator 12. ing.

  A first joint portion 24 that can be rotated around an axis perpendicular to the table 40 is attached to the fixed portion 22, and the first joint portion 24 is horizontal to the upper surface of the table 40. A first arm portion 26 capable of rotating around the axis is attached. The distal end of the first arm portion 26 is connected to the second arm portion 30 via the second joint portion 28, and the second arm portion 30 is centered on an axis that is horizontal to the upper surface of the table 40. Rotation is possible. A third joint portion 32 is attached to the distal end of the second arm portion 30 and is rotatable about an axis that is horizontal with respect to the upper surface of the table 40. A third arm portion 34 that is rotatable about an axis along the longitudinal direction of the second arm portion 30 is attached to the end portion 32 a of the third joint portion 32. That is, the third arm portion 34 can be rotated in the vertical direction with respect to the table 40 and can be rotated (spinned) about the axis along the longitudinal direction of the third arm portion 34. . Further, the fourth joint portion 36 connects the third arm portion 34 and the distal end portion 38 so that the distal end portion 38 can rotate around the axis line along the longitudinal direction of the third arm portion 34. Composed.

  The mounting portion 16 attached to the distal end portion 38 has a columnar shape that can be easily gripped by the user. A known gripping mechanism such as a drill chuck is provided at the tip of the mounting portion 16, and the handle portion 14 a of the spoon 14 can be easily attached to and detached from the mounting portion 16 through the gripping mechanism. The spoon 14 attached to the mounting part 16 is a general one used for meals, and moves while the receiving part 14b is always maintained in a horizontal posture during transportation. The liquid that can be transported without overflowing by the liquid transport apparatus 10 includes liquids such as water, soup, miso soup, and liquids (liquid food) such as jelly and pudding.

  The operation switch 20 includes an operation start button 20a and an operation stop button 20b, and is electrically connected to the control unit 18. Then, when the user presses the operation start button 20a, the operation switch 20 transmits an operation signal to the control unit 18, and the control unit 18 starts the operation of the manipulator 12. When the user presses the operation stop button 20b, the operation switch 20 transmits a stop signal to the control unit 18, and the control unit 18 performs control to stop the manipulator 12. However, the control unit 18 does not stop the manipulator 12 immediately, but stops the spoon 14 while decelerating it based on a deceleration curve T described later. The operation switch 20 is installed on the upper surface of the table 40 at a position where the operator can easily operate.

The controller 18 controls the operation of the motors so that the spoon 14 (liquid) is transported along a predetermined transport path C and transport speed curve V. Here, in order to describe the control mode of the manipulator 12 by the control unit 18, an XYZ orthogonal coordinate space as shown in FIG. 2A is set. Then, the position of the spoon 14 in a state where the liquid is poured is set as a starting point O (origin), and a point (for example, the user's mouth) spaced from the starting point O by a predetermined interval is set as the end point P. For convenience of explanation, the end point P (stop position of the spoon 14) is set so that the _XY coordinate component PXY of the end point P is located on the Y axis. As shown in FIG. 2B, the spoon 14 is transported in a posture in which the handle portion 14a extends in the X-axis direction.

First, the conveyance path C of the spoon 14 is set as follows. The control unit 18, X-Y coordinate component _{C X-Y} of conveyor track C spoon 14 controls the manipulator 12 so as to be straight. That is, as shown in FIG. 2 (b), X-Y coordinate component _{C X-Y} of conveyor track C spoon 14, on the Y axis connecting the X-Y coordinate component _{P X-Y} of the end point P from the starting point O Draw a straight orbit. However, when the transport track C of the spoon 14 is viewed on the YZ coordinate plane, the track is curved (see tracks C ₁ and C ₂ ), or a straight line (track) connecting the start point O and the end point P. may be a C reference _3). In addition, the conveyance track | orbit C (conveyance distance) of the spoon 14 changes with the timing of the stop command (ON of the operation stop button 20b) by a user.

Next, the control unit 18 controls each motor so as to convey the spoon 14 at a preset conveyance speed curve V so that the liquid does not overflow during acceleration / deceleration. Here, if the acceleration (deceleration) in the Z-axis direction is about the acceleration of a normal meal operation, the action on the liquid is small and the influence on the liquid level fluctuation is small. Therefore, the acceleration / deceleration in the Z-axis direction with respect to the spoon 14 can be ignored. That is, whether or not the liquid overflows from the spoon 14 has a problem of acceleration / deceleration in the Y axis direction (XY coordinate plane direction). Therefore, when setting the conveying speed curve V spoon 14, Y-axis direction component (X-Y coordinate component, hereinafter referred to as the degradation rate curve V _X-Y) it is sufficient to set the. Moreover, as mentioned above, since the X-Y coordinate component C _X-Y of conveyor track C spoon 14 is a straight line, the liquid transport problems in three-dimensional space, be simplified as linear conveyance control problem of liquid (See FIG. 2B).

FIG. 3 is a graph illustrating an example of the decomposition speed curve V _XY and acceleration set in the liquid transport apparatus 10 according to the embodiment. The decomposition speed curve V _XY includes an acceleration stage in which the spoon 14 is accelerated by the acceleration curve S, a constant speed stage in which the spoon 14 is moved at a speed at the end of the acceleration (hereinafter referred to as a target decomposition speed V ₁ ), and deceleration. It is comprised from the deceleration stage which decelerates the spoon 14 with the curve T. FIG. The acceleration curve S is set so that the acting force applied to the liquid during acceleration is smaller than the surface tension of the liquid filled in the spoon 14. As will be described later, the specific derivation of the acceleration curve S is not limited to the surface tension of the liquid, and the constraint condition that suppresses the degradation of the decomposition rate curve V _X-Y as much as possible (general movement speed ( This is performed by searching for an unknown parameter using a genetic algorithm under acceleration to the target decomposition speed V ₁ ).

The acceleration phase spoon 14 which is accelerated to the target degradation rate V ₁ at, the process proceeds to the constant velocity stage, is conveyed a predetermined time, the target degradation rate V _1. The target degradation rate V ₁ was, for example, generally an adult male is set to the operating speed in the diet. The time of the constant speed stage is the time from when the decomposition speed curve V _XY reaches the target decomposition speed V ₁ until the user presses the operation stop button 20b (see FIG. 3). The deceleration curve T is set to a curve obtained by inverting (axisymmetric) the acceleration curve S with respect to the time axis. That is, the decomposition speed curve V _XY of the spoon 14 is decelerated in a pattern opposite to that at the time of acceleration in the deceleration stage, and can thereby be stopped without overflowing the liquid. Therefore, as shown in FIG. 3, the graph of the decomposition speed curve V _XY is symmetrical. The component in the Z-axis direction of the conveyance speed curve V is appropriately accelerated / decelerated within a range corresponding to the normal meal operation speed, and becomes 0 when the spoon 14 reaches the height position of the end point P. The control unit 18 stores a plurality of transport trajectories C and transport speed curve V (decomposition speed curve V _XY ) patterns according to the shape of the spoon 14, the type of liquid, and the like.

(About the operation of the embodiment)
Next, the operation of the liquid transport apparatus 10 according to the embodiment will be described. When the user grips the mounting portion 16 of the manipulator 12 and gives an operation command to the control unit 18, first, the control unit 18 operates the first to sixth motors to draw liquid from a container (not shown) into the spoon 14. I will meet you. The spoon 14 filled with the liquid becomes a horizontal posture and stands by at the starting point O. Next, when the user presses the operation start button 20 a of the operation switch 20, the control unit 18 moves the spoon 14 with a preset conveyance speed curve V. That is, the controller 18 controls the respective motors, X-Y coordinate component C _X-Y in the transport trajectory C of the spoon 14 to convey the so spoon 14 as a straight line along the Y-axis direction. Further, the control unit 18 accelerates the decomposition speed curve V _XY of the spoon 14 based on the acceleration curve S. At this time, the acceleration curve S is set such that the acting force acting on the liquid during acceleration is smaller than the surface tension of the soup, so that the liquid does not overflow from the spoon 14 during acceleration.

In the acceleration stage, when the decomposition speed curve V _XY of the spoon 14 is accelerated to the target decomposition speed V ₁ (see FIG. 3), the control unit 18 controls each motor to make the spoon 14 have the target decomposition speed V 1. ₁ to move at a constant speed (transition to the constant speed stage). When the user presses the operation stop button 20b of the operation switch 20, the control unit 18 decelerates the decomposition speed curve V _XY of the spoon 14 based on the deceleration curve T. Here, since the deceleration curve T is a curve obtained by inverting the acceleration curve S on the time axis, the acting force of the liquid by the deceleration curve T does not exceed the surface tension of the liquid. Therefore, the spoon 14 can be decelerated without overflowing the liquid. And the spoon 14 decelerated by the deceleration curve T stops near the user's mouth (end point P). When the end point P is reached, the control unit 18 controls each motor to tilt the spoon 14 so that the user can easily put the liquid into the mouth.

(Calculation method of acceleration curve S)
Next, a specific method for calculating the acceleration curve S will be described below. Here, the fluid analysis software FLOW-3D is used to analyze the behavior of the liquid on the spoon 14, and the free surface calculation of the liquid is performed using VOF (Volume of Fluid, CWHirt, BDNichols, “Volume of Fluid (VOF) Methods for the Dynamics of Free. Boundaries ”, Journal of Computational Physics, Vol. 39 (1981), pp. 201-255). Further, the complicated geometry of the spoon 14 was recognized using a FAVOR (Fractional Area Volume Obstacle Representation) function which is a kind of volume ratio technique. A 6-DOF manipulator manufactured by Yaskawa Electric was adopted as the liquid transfer device 10. The specifications of the apparatus are shown in Table 1, and the shape and dimensions of the receiving portion 14b of the spoon 14 are shown in FIG. The mesh width of this simulator was set so that one analysis time was about 15 minutes. Table 2 shows mesh parameters in the simulation region at that time. In this case, the total number of meshes is 175000.

Ordinary tap water was used as the liquid, and the amount of the liquid was set to 4.7 × 10 ⁻³ [l] so that the spoon 14 was completely worn out. Table 3 shows the simulation parameters at the time of analysis. In addition, about the contact angle of tap water, since the shape of the spoon 14 was complicated, it determined by performing a simulation analysis.
A liquid analysis simulator based on the above conditions is constructed, and the acceleration curve S is derived.

First, the acceleration curve S is formulated using a function represented by an equation (Equation 2) obtained by differentiating an equation (Equation 1) representing the decomposition speed curve V _XY . Here, t is time, a _i (i = 0 to n) is a constant, and n = 7 in consideration of the balance between calculation time and analysis accuracy. However, the order n is not limited to 7, and may be n = 6 or less, or n = 8 or more.
Next, in consideration of the initial condition of conveyance and the termination condition at the acceleration end time t ₁ , v (0) = 0.0 [m / s], a (0) = 0.0 [m / s ² ], v ″ (0) = 0.0 [m / s ³ ], f (t ₁ ) = V ₁ (target decomposition speed) [m / s], a (t ₁ ) = 0.0 [m / s ² ], V ^″ (t ₁ ) = 0.0 [m / s ³ ].
As a result, Expression (Expression 3) to Expression (Expression 6) can be obtained from these conditions.
There are four unknown parameters to be searched for: t ₁ , V ₁ , a ₇ , a ₆ . Here, V ₁ is a motion capture that uses motion capture to measure the movements of ordinary adult men when eating, and obtains the average speed from the time the object (liquid) is taken to the mouth by analysis. It was. As a result, V _{1 was set to} 0.37 [m / s]. By setting the target decomposition speed V ₁ to such a value, a decrease in the conveyance speed V of the spoon 14 can be suppressed as much as possible.

For parameter optimization, this problem is formulated into a constrained optimization problem using a penalty term as shown in Equation (7).
Here, in Expression (Equation 8), t is time, P is the position at time t ₁ , T _s is the production time, and P _f is the position at the end of acceleration (end point P). Penalty _{J P} of equation (9) is, ω _k = 10 ⁸ if not satisfied constraint (k = 1, 2, · · ·) give. The constraint conditions include an equation for the velocity to be positive (Equation 10), an equation for satisfying the velocity constraint on each axis of the six-degree-of-freedom manipulator (Equation 11), and an equation for preventing the liquid from overflowing (Equation 12). These are expressed as Penelty functions. Here, the expression (Equation 12) is evaluated with the aid of the fluid analysis simulator described above.

Next, an optimal solution for the acceleration curve S is derived. Here, the origin is set at the base of the manipulator, the position of (X, Y, Z) = (0.45, 0.00, 0.30) [m] is set to the start point O and 0.30 [ m] The position of the moved (X, Y, Z) = (0.45, 0.30, 0.30) [m] was set as the end point P, and the optimization problem was solved. At this time, the parameters of the genetic algorithm were set as shown in Table 4.

The obtained optimization results are shown in FIG. As a result, it converged to 1.42 [s] in the 13th generation. FIG. 6 shows the obtained speed curve (acceleration stage decomposition speed curve V _XY ) and acceleration curve S. At this time, each parameter is t ₁ = 0.62 [s], a ₇ = −14.808, a ₆ = 25.073, a ₅ = 12.407, a ₄ = −37.692, a ₃ = 16. 365. FIG. 7 shows the angular velocity of each axis in the six-degree-of-freedom manipulator 12. Here, the upper and lower limits of the graph represent the maximum speed constraint of the six-degree-of-freedom manipulator 12, and it can be seen from this that the conveyance can be performed within the limit of the six-degree-of-freedom manipulator 12. FIG. 8 shows the simulation result, and it can be seen that the liquid can be transported without overflowing.

(Liquid transfer experiment)
Next, a liquid conveyance experiment was performed by an overflow prevention control system (this method) using the acceleration curve S (deceleration curve T) obtained by the above method. As a comparative example, a liquid transfer experiment using a positioning control system based on proportional control and a vibration control system based on a hybrid shaping method is performed and compared with this method. FIG. 9 shows the transfer trajectory, speed curve, and acceleration curve of the control experiment result by each control method. Moreover, the liquid behavior of the actual spoon in each experiment is shown in FIGS. Here, the solid line, the broken line, and the alternate long and short dash line in FIG. 9 indicate the experimental results by the overflow prevention control, the hybrid shaping method, and the proportional control, respectively. As shown in FIG. 12, when transported with the acceleration curve S (deceleration curve T) obtained by the present method, the transport time can be transported without overflowing the liquid even though the transport time is the same as that of the comparative example. I understand that. On the other hand, as shown in FIGS. 10 and 11, in the acceleration (deceleration) curve obtained by the hybrid shaping method and the proportional control, the liquid overflows from the spoon during conveyance (see circles in FIGS. 10 and 11). ).

As described above, according to the liquid transport device 10 according to the embodiment, the liquid can be transported to the user's mouth without overflowing the liquid at a speed close to a normal meal operation. Further, if only the acceleration curve S of the decomposition speed curve V _XY is set, it is not necessary to obtain the acceleration / deceleration curve in the entire transport path C, so that the calculation time can be greatly shortened. Moreover, by a straight line X-Y coordinate component C _X-Y of the transport track C, and liquid transport problems in three-dimensional space can be simplified as linear conveyance control problem of a liquid, further suppressing the amount of computation Can do. Further, since the acceleration curve S is defined by parameters obtained by searching with a genetic algorithm, the calculation time for deriving the acceleration curve S is suppressed, and calculation with a general computer becomes possible.

In addition, although the liquid conveying apparatus 10 demonstrated in the Example was an apparatus aiming at meal assistance, as a liquid conveying apparatus which concerns on this invention, it is not necessarily limited to meal assistance, For example, an industrial robot etc. It can be applied as a device for various uses. Moreover, in the Example, although the spoon 14 was employ | adopted as an accommodating part, if a liquid can be accommodated, a dish, a lotus root, etc. may be sufficient. Further, the deceleration curve T of the embodiment is a curve obtained by inverting the acceleration curve S on the time axis. However, the deceleration curve T is derived separately, and the decomposition speed curve V _XY with a deceleration pattern different from the acceleration curve S is obtained. You may make it decelerate. In the liquid transport apparatus 10 of the example, the acceleration curve S and the deceleration curve T are set so as not to exceed the surface tension in consideration of the surface tension of the liquid. However, in addition to the surface tension, the velocity curve S and the deceleration curve T may be set so as not to exceed the inward force of the liquid based on the viscosity, weight, etc. of the liquid (force that works inward so that the liquid does not overflow). .

  In the embodiment, ON / OFF of the liquid transport apparatus 10 is operated by the operation switch 20. However, for example, when a sensing sensor is provided in the mounting portion 16 of the manipulator 12 and the user touches the mounting portion 16, the manipulator 12 automatically operates, and when the user releases the hand from the mounting portion 16, The manipulator 12 may be automatically decelerated and stopped. Alternatively, the end point P of the spoon 14 may be fixed, and the manipulator 12 may transport the spoon 14 on the constant transport path C and stop at the end point P simply by the user giving an operation start command. Furthermore, it is also possible to provide the liquid transport apparatus 10 with a transport distance measuring means that recognizes the user's mouth (end point P) and automatically measures the distance from the start point O to the end point P. Then, based on the transport distance measured by the transport distance recognition means, the control unit 18 adjusts the time of the constant speed stage (that is, the distance transported at the constant speed), and the spoon 14 is automatically set at the end point P. It can also be stopped. In this case, the user does not need to give a stop command to the manipulator 12, and the spoon 14 automatically stops at the user's mouth.

It is a perspective view which shows the whole structure of the liquid conveying apparatus which concerns on an Example. It is explanatory drawing which shows the conveyance track | orbit of a spoon, Comprising: (a) shows a conveyance track | orbit by XYZ coordinate, (b) shows the XY coordinate component of a conveyance track | orbit. It is a graph which shows the decomposition | disassembly rate curve and acceleration of a spoon. It is explanatory drawing which shows the dimension of the receiving part of a spoon, Comprising: (a) is a top view, (b) is a front view, (c) shows a side view. It is a graph which shows the result of optimization. It is a graph which shows the decomposition speed curve and acceleration curve of the acceleration stage derived | led-out by optimization. It is a graph which shows the angular velocity of each axis | shaft of a manipulator. It is a figure which shows the simulation result of a liquid conveyance. It is a graph which shows the control experiment result by each control method, (a) is a conveyance track, (b) is a speed curve, (c) shows an acceleration curve. It is a photograph which shows the result of the liquid conveyance experiment by proportional control. It is a photograph which shows the result of the liquid conveyance experiment by a hybrid shaping method. It is a photograph which shows the result of the liquid conveyance experiment by this method.

Explanation of symbols

14 spoon (accommodating part), 18 control part, 26 1st arm part 30 2nd arm part, 34 3rd arm part, C transport track C _—XY transport track XY coordinate component, O start point, P end point, S acceleration curve T deceleration curve, V transport speed curve, V ₁ target decomposition speed V _XY decomposition speed curve (XY coordinate component of transport speed curve)

Claims (3)

A storage unit (14) for storing the liquid and transporting the liquid from the start point (O) to the end point (P) on the XYZ orthogonal coordinates;
An arm part (26, 30, 34) for supporting the accommodating part (14) and moving the accommodating part (14);
A drive section for driving the arm sections (26, 30, 34);
A control unit (18) for controlling the drive unit so that the _XY coordinate component (C _XY ) in the transport path (C) of the storage unit (14) is a straight line;
The control unit (18) is configured such that the _XY coordinate component (V _XY ) in the transport speed curve (V) of the storage unit (14) accelerates the storage unit (14) with a predetermined acceleration curve (S). A constant speed stage in which the accommodating part (14) is moved at a speed (V ₁ ) at the end of acceleration, and a deceleration stage in which the accommodating part (14) is decelerated by a predetermined deceleration curve (T) Control the drive so that
The acceleration curve (S) and the deceleration curve (T) are set so that the acting force acting on the liquid at the time of acceleration or deceleration is smaller than the surface tension of the liquid filled in the container (14). A liquid transporting device.   The liquid transport apparatus according to claim 1, wherein the deceleration curve (T) is set to a curve obtained by inverting the acceleration curve (S) on a time axis.   3. The liquid transfer device according to claim 2, wherein the parameter of the acceleration curve (S) is obtained by searching with a genetic algorithm under a constraint condition in which an acting force on the liquid during acceleration is smaller than the surface tension.