JP3788920B2 - Power assist device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a power assist device that assists an operation force with an assist force that is determined and output based on an operation force of an operator who operates an object to be operated or whose posture is to be changed.
[0002]
[Prior art]
As a conveyance auxiliary device, for example, an air balancer type device is known. In a conventional air balancer-type transport assist device, gravity compensation is performed in order to achieve gravity balance, but inertia compensation relating to momentum is not performed.
[0003]
[Problems to be solved by the invention]
Therefore, conventionally, inertia compensation as described above is left to the operator's operating skill, and when a beginner or the like works, especially when changing the direction of a transported object with a large momentum, etc. Such a large force is required, the burden is large, and it is not desirable in terms of work efficiency.
[0004]
The present invention has been made to solve the above-described problems, and an object of the present invention is to realize a power assist device that assists a beginner or the like to efficiently and accurately acquire operation skills possessed by an expert. That is.
[0005]
[Means for Solving the Problem, Action, and Effect of the Invention]
In order to solve the above problems, the following means are effective.
That is, the first means includes a force sensor that detects an operation force F _h of an operator who operates an object to be moved or changed in posture, and is determined and output based on the operation force F _h. In the power assist device for assisting the operation force F _h by the assist force A, based on sample data regarding the sample, such as the object transportation route or the operation force F _h , which is embodied by an expert, an experimenter, or a subject. An assist force correcting unit that corrects the assist force A is provided, and the assist correcting unit corrects the assist force A according to a correction force that is a difference between the operation of the operator and the operation of the sample data .
[0006]
According to such a means, for example, by recording, for example, an operation method of an expert (an operation mode such as a so-called knack) as the sample data, the operation skill of the assist force A for the operation of the beginner (operator) is related. When correcting, the assisting force A is a force that corrects the operation of the beginner so that the operation of the beginner is close to the operation of the expert (hereinafter referred to as “correcting force”) as one component thereof. It becomes possible to add (add).
[0007]
The above-mentioned sample data created based on the operation of the expert includes so-called “work tips” that change according to the work contents and the characteristics of the object in an optimized form based on the experience of the expert. It is thought that.
Further, the correction force can be increased as the operation direction and the operation force of the skilled person and the operator (beginners etc.) are different.
[0008]
Therefore, the posture and operation of the operator can be corrected with such correction force, and the operator feels the external force (correction force), so depending on the external force, any transport route can be used. “Expert's operation method” such as how to operate efficiently can be learned sensuously.
[0009]
Therefore, according to such means, it is possible to support a beginner or the like to efficiently and accurately acquire the operation skill possessed by the expert. Moreover, not only the sample data of the skilled person but also the sample data of a large number of subjects may be statistically processed to constitute the representative sample data similar to the above. According to such means, the above means can be operated even if there is not necessarily a skilled person.
[0010]
In addition, by performing the operation support as described above, the following effects can be greatly expected while a beginner or the like learns the operation skill possessed by the expert and after completion of the acquisition.
(Effect 1) Reduction of operator fatigue.
(Effect 2) Reduction of operator error.
(Effect 3) Reduction of operator's work time.
[0011]
The power assist device according to the first means does not necessarily include a means for sampling or recording sample data. The above means operates based on the recorded sample data.
[0012]
The second means is the first means of the skilled person, experimenter, or is embodied by the subject or the like, such as conveying path or the operating force F _h of the object, sample for recording sample data about the sample A data recording means;
According to such means, it is possible to record the sample data and generate the assist force based on the sample data by one power assist device. Such a means is particularly effective when reproduction of the site where the power assist device is installed is not easy elsewhere, or when a skilled person can easily visit the site.
[0013]
The third means is the sample data recording means of the second means described above, every predetermined sampling period, and to record the position r and the operating force F _h on the conveying path. In this specification, r is a two-dimensional or three-dimensional position vector, and F _h is a two-dimensional or three-dimensional force vector.
According to such a means, in a case such as the transport path of the skilled person recorded in the transport path of the operator and sample data substantially coincide, the operation force F _h of the operator, are recorded in the sample data It is possible to implement a method such as generating a correction force so as to be closer to the operation force of a skilled worker. Further, the position r corresponds to whether or not the operator's transportation route and the skilled worker's transportation route recorded in the sample data substantially match, or which point on the transportation route corresponds to which point. It can be used to determine whether or not.
[0014]
Further, the fourth means is the assist force correction means of any one of the first to third means described above, wherein the transport route in the route record information on the object operated by the operator in the past, or the operator Select the transportation route most similar to one of the current transportation routes of the object currently being operated from among the plurality of transportation routes in the sample data collected by multiple samplings. It is provided with a similar conveyance route selection means.
[0015]
According to such a means, when a plurality of sample data is prepared, the sample data can be effectively used after automatically selecting a transport route suitable for the purpose.
Or, according to such means, the sample data of the expert who is closest to the user (operator) in terms of physique, physical strength, how to take the transportation route, or how to move the body during operation, etc. Can be selected. For this reason, the operator can acquire the operation skill of an expert who is closest to himself / herself and is suitable for himself / herself within the shortest time.
The fifth means is that the assist force correcting means is the operator's operation force at the position of the object closest to the current position of the object operated by the operator when the expert operates, and the current position of the operator. If the angle exceeds the predetermined value, the assist force is obtained after replacing the current operation force of the operator with 0, and if the angle is less than the predetermined value, The assisting force is obtained after replacing the operator's current operating force with a weighted average of the operator's current operating force and the skilled operator's operating force.
By the above means of the present invention, the above-mentioned problem can be effectively or rationally solved.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on specific examples. However, the present invention is not limited to the following examples.
〔Example〕
1, 2, and 3 are perspective views illustrating a power assist device 100 according to each embodiment of the present invention. The operator grips the object 10 with the hand 152 provided at the tip of the operation unit 150 and tries to move the object 10 from the placement table 20 to the placement table 21 by the power assist device 100.
Hereinafter, in this embodiment, the position r and the operating force F _h are each a three-dimensional vector.
[0017]
The power assist device 100 is supported by a total of four vertical vertical anchors 111 fixed to the ground surface, and the individual elastic bands 111 are connected to each other by a total of four horizontal rails 112. The moving wheel 181 (for moving the x-direction rod) and the moving wheel 182 (for moving the y-direction rod) can move (roll) while rotating on each rail 112. The x coordinate of the control point in the coordinate system of this mechanical system is increased or decreased by the amount of displacement that the y-direction rod 122 has moved in parallel. Similarly, the y-coordinate of the control point in this coordinate system increases or decreases by the amount of displacement that the x-direction rod 121 rolls and translates. In general, a control point (a point whose position is to be controlled) is fixed near the tip of the hand 152 or the center of gravity of the object 10 held by the hand 152.
[0018]
Since the two moving wheels 181 (for moving the x-direction rod) are connected by the x-direction rod 121, the x-direction rod 121 and the two moving wheels 181 (for moving the x-direction rod) are in the same direction at the same rotational speed. Move while rotating. At this time, the moving wheel 181 (for moving the x-direction rod) rolls on the rail 112. The same applies to the y-direction rod 122 and the two moving wheels 182 (for y-direction rod movement).
[0019]
The x-direction rod 121 is received by a bearing 141, and the y-direction rod 122 is received by a bearing 142. These bearings are constituted by a bearing mechanism. Since these bearings are fixed to the central base 140, the central base 140 can freely move on the xy plane as each rod moves. In addition, a z-axis bearing female screw tube 143 is fixed to the central base 140 so as to pass through the substantial center in the vertical direction so as to be rotatable with respect to the tube axis. This male screw constituting the pair is received by the female screw tube 143 for z-axis bearing. Since the z-axis bearing female screw tube 143 is driven to rotate by the z-axis moving motor 163, the z-axis 130 moves in the vertical direction as the z-axis bearing female screw tube 143 rotates. be able to. Usually, the position of the tube axis on the xy plane is selected as a control point on the xy plane.
[0020]
Inside the operation unit 150, a 6-axis force sensor (not shown) for detecting the magnitude and direction of the operation force F _{h applied} to the operation handle 151, and the weight (mass m) of the object 10 are measured. A built-in weighing scale (not shown). The detected weight (mass m) and operating force F _h of the object 10 are input to a predetermined computer (not shown) wirelessly or by wire.
Further, operation switches such as an emergency stop button (not shown) are arranged on a surface (console plate) of the operation unit 150 facing the operator side. Further, a small camera (not shown) is mounted on this surface (console plate), and the distance d from the operation unit 150 to the operator can be measured as needed.
[0021]
The output torque of the motor 161 for moving the x-direction rod is transmitted to the x-direction rod drive gear 171, the x-direction rod drive shaft 172, and the two x-direction rod drive belts 173, and this output torque is used for moving the x-direction rod. The moving wheel 181 and the x-direction rod 121 are moved (rolled) in the y-direction rod direction. The same applies to the output torque of the motor 162 for moving the y-direction rod.
[0022]
FIG. 4 is a hardware configuration diagram of a motor control device 200 that constitutes a control unit of the power assist device 100 according to each embodiment of the present invention. This device 200 includes the axes (x, x, x) of the assist device 100 described above. Each y, z) is prepared logically or physically.
[0023]
The brushless DC motor M of FIG. 4 that generates assist torque (hereinafter simply referred to as “motor M”) has motor drive currents for the three phases U, V, and W via the current detector 215 from the drive circuit 213. iu, iv, iw are supplied. However, the form (realization form) of the motor M is not particularly limited to a three-phase motor or the like, and an arbitrary form of motor may be used.
2 and 3 is provided with a force sensor 232 (FIG. 4) for detecting the magnitude and direction of the operating force H applied by the operator. The force sensor 232 can be mounted with, for example, a commercially available 3-axis to 6-axis force sensor.
The motor M is provided with a rotation angle sensor (encoder) E that detects the motor rotation angle, and the CPU 210 determines the rotation angle of the motor M based on a predetermined output signal of the motor M output from the rotation angle sensor E. Calculate.
[0024]
The motor control device 200 includes a CPU 210, a ROM 211, a RAM 212, a drive circuit 213, an input interface (IF) 214, a current detector 215, and the like. The drive circuit 213 includes a battery (not shown), a PWM converter, a PMOS drive circuit, and the like, and supplies electric power to the motor M by changing the drive current to a sine wave by chopper control.
[0025]
The motor control device 200 inputs the operating force H, the rotation angle of the motor M, and the motor drive currents iu and iv to the CPU 210 via the input interface (IF) 214, and determines a predetermined torque from these input values. The current command value is determined by calculation.
The input interface (IF) 214 also has an interface with a personal computer (PC) 250, and reads and updates the database as necessary, or inputs various parameters and commands (commands). Can be executed.
[0026]
FIG. 5 is a control block diagram illustrating a basic control method of the power assist device 100 according to each embodiment of the present invention. For example, the motor 161, the motor 162, or the motor 163 can be controlled by such a control method. The present invention is, for example, has been made in order to reasonably control the power assist device 100 such as described above, the present invention is primarily, in Figure 5 for calculating the assist force A on the basis of the operating force F _h The present invention relates to various calculation means for realizing the assist calculation unit 400 on a computer system (not shown).
[0027]
FIG. 6 is a general flowchart illustrating the execution procedure of the operation storage mode of the power assist device 100.
In this flowchart, first at step 510, A / D conversion of analog signals of the operation force F _h obtained from the force sensor into a digital signal.
[0028]
Next, in step 520, a signal having an unnecessary frequency such as noise is removed by a well-known filtering process on the converted digital signal (current value of the operating force F _h ).
In step 530, it is determined whether or not the operation storage mode is currently set. If the operation storage mode is in effect (within the work pattern storage time), the process proceeds to step 540, and if not, the process proceeds to step 570.
[0029]
In step 540, the position r of the current control point ("current value P" in the figure) is calculated based on the encoder output value (encoder value) input from the encoder.
In step 550, the calculated position r of the control point ("current value P" in the figure) is stored in a predetermined storage area.
In step 560, the value of the current operating force F _h obtained in step 520 is stored in a predetermined storage area in association with the “current value P”.
[0030]
In step 570, the assist force A is calculated according to the following equation (1).
[Expression 1]
A = αF _h (1)
Here, α is a predetermined assist ratio (scalar).
Steps 530 to 570 described above correspond to the processing of the assist calculation unit 400 in FIG.
[0031]
In step 580, based on the value of the assist force A = (A _x , A _y , A _z ), current values (current command values) to be supplied to the motors 161, 162, 163 are calculated. In this calculation method, as illustrated in FIG. 5, for example, the current command value may be calculated in the order of “assist force A → speed command value → current command value”, or “assist force A → torque The current command value may be calculated in the order of “command value → current command value”.
[0032]
In step 590, so-called “motor control” for driving the motors 161, 162, and 163 by well-known chopper control or the like is executed. However, this step 590 may be implemented entirely by hardware throughout.
By executing the “operation storage mode” as described above, it is possible to record the operation state of the expert as “sample data” in a predetermined storage area.
[0033]
FIG. 7 is a general flowchart illustrating the execution procedure of the operation support mode of the power assist device 100.
Hereinafter, the following symbols (subscripts) may be used in the drawings of the present specification.
[The meaning of the subscript attached to the force vector F]
h maturity… expert's operation power h first stored as “sample data”… beginner's operation force before correction (detection value)
h first_new… New operation force after correction (correction value)
[0034]
In the “operation support mode”, first, in step 610, the power assist device 100 is initialized. In this processing, various initial inspections such as hardware check and initialization of the computer system are performed.
Next, in step 620, the sample data (expert data) recorded in the “operation storage mode” is read into a predetermined storage area.
[0035]
In step 630, the analog signal of the operation force obtained from the force sensor is A / D converted into a digital signal.
Next, in step 640, a signal having an unnecessary frequency such as noise is removed by a well-known filtering process on the converted digital signal (current operating force value).
[0036]
In step 650, a subroutine for “operation force correction” which will be described later is called and executed. Thereby, the value of the beginner's operation force used for the assist force calculation process (calculation of the assist force A) is corrected based on the value of the operator's operation force in the sample data.
[0037]
In step 660, the value of the assist force A is calculated based on the corrected operation force (correction value) of the beginner based on the equation (1). However, the following general formula (2) may be used instead of the above formula (1). As the function f in the equation (2), for example, a broad monotonically increasing function having an upper limit can be used, and a function that is suitably or optimally tuned may be used.
[Expression 2]
A = f (F _h ) (2)
[0038]
In step 670 and step 680, processing similar to that in steps 580 and 590 described above is executed. However, in step 670, the current command value calculation based on the calculation of the torque command value is executed in the order of “assist force A → torque command value → current command value”.
[0039]
FIG. 8 is a flowchart illustrating the execution procedure of a subroutine for realizing the “operation force correction process” in the operation support mode. This subroutine is called and executed in step 650 of FIG.
First, in this subroutine, the current control point position r (“current value P” in the figure) is calculated based on the encoder output value (encoder value) input from the encoder (step 710).
[0040]
Next, in step 720, a point closest to the current position r of the current control point is searched from the set of sampling points located on the transport route indicated by the sample data (expert data), and the expert at that point is searched. Find the operating force of.
[0041]
In step 730, an angle θ formed by the direction of the operating force of the current operator (beginner) and the direction of the operating force of the skilled worker obtained in step 720 is calculated.
In step 740, the magnitude of the angle θ is determined. If 90 ° or less, the process proceeds to step 760, and if not, the process proceeds to step 750.
However, these determination processes may be performed by the sign of the calculation result of the inner product of the operation force of the current operator (beginner) and the operation force of the expert. Such a method is particularly effective in an apparatus using an orthogonal coordinate system such as the power assist apparatus 100 described above.
[0042]
In step 750, the corrected operation force (correction value) for the beginner is set to zero. Thereby, when the operation direction is greatly different from 90 ° with respect to the operation force of the expert, the output of the assist force A is suppressed.
In steps 760 and 770, the corrected operation force (correction value) for the beginner is determined as shown in the figure. Here, n represents a correction rate, and an arbitrary value between 0 and 1 can be set as the value of n. Such a parameter (n) may be changed according to the situation such as the proficiency level of the operator (beginner).
[0043]
In step 760, when determining the correction force, the following correction term ΔF may be added as a new term constituting the correction force.
[Equation 3]
ΔF = κΔs (3)
Here, Δs is a displacement vector representing the amount of positional deviation between the expert's transport route and the beginner's transport route, and κ is an appropriate constant. Alternatively, the absolute value | ΔF | of ΔF may be proportional to the first to third powers of the absolute value | Δs | of Δs.
[0044]
Further, step 760 described above may be omitted (deleted), and the right side of the substitution formula in step 770 may be changed to “(expert's operating force) + (beginner's operating force) × η” or the like. Here, η is an appropriate positive number.
[0045]
For example, according to the above-described means, the value of the novice operation force used for the assist force calculation process (calculation of the assist force A) such as Equation (1) or Equation (2) is recorded. Since correction (correction) is performed in step 770 according to the operation mode of the expert, an appropriate correction force can be generated. Therefore, this correction force can assist a beginner or the like to efficiently and accurately acquire the operation skill possessed by the expert.
[0046]
Moreover, not only the sample data of the skilled person but also the sample data of a large number of subjects may be statistically processed to constitute the representative sample data similar to the above. According to such means, the above means can be operated even if there is not necessarily a skilled person.
[0047]
In the above embodiment (FIG. 8), the amount of sample data (expert data) was not mentioned, but a plurality of sets of sample data were collected by sampling a plurality of times, and the similar transport of the present invention was performed. By using route selection means or the like, only one set of sample data that seems to be most suitable may be automatically selected from the plurality of sets of sample data. The determination of whether or not the transportation routes are similar can be performed using a known information processing method such as a least square method.
According to such means, the above-described sample data can be effectively utilized after automatically selecting a predetermined transportation route that meets the purpose.
[0048]
Alternatively, according to such means, sample data of an expert who is close to the user (operator) in terms of physique, physical strength, how to take the transportation route, or how to move the body during operation is automatically obtained. It becomes possible to select. For this reason, the operator can acquire the operation skill of an expert who is close to himself / herself and is suitable for himself / herself within a sufficiently short time.
[0049]
In addition, at the initialization of step 610 in FIG. 7, the apparatus is selected based on items such as gender, age, height, weight, or various muscular strengths and physical strengths from a large number of sample data (expert data). Using a similar transport route selection means, etc., from the sample data of skilled workers who have been narrowed down to some extent, obtain a set of skilled workers who are considered to be close to the operator (beginners) who use the In addition, only one set of sample data that seems to be most suitable may be automatically selected. By such means, the operator can acquire the operation skill of an expert who is closest to himself / herself within the shortest time and is suitable for the person himself / herself.
[Brief description of the drawings]
FIG. 1 is a perspective view illustrating a power assist device 100 according to an embodiment of the invention.
FIG. 2 is a perspective view illustrating a power assist device 100 according to an embodiment of the invention.
FIG. 3 is a perspective view illustrating a power assist device 100 according to an embodiment of the invention.
FIG. 4 is a hardware configuration diagram of a motor control device 200 that constitutes a control unit of the power assist device 100 according to the embodiment of the present invention.
FIG. 5 is a control block diagram illustrating a control method of the power assist device 100 according to the embodiment of the invention.
6 is a general flowchart illustrating an execution procedure of an operation storage mode of the power assist device 100. FIG.
7 is a general flowchart illustrating an execution procedure of an operation support mode of the power assist device 100. FIG.
FIG. 8 is a flowchart illustrating an execution procedure of a subroutine for realizing “operation force correction processing” in the operation support mode.
[Explanation of symbols]
m ... Mass of the object to be operated (scalar)
F _h ... Operating force of the operator (vector)
A ... Assist force (vector) output by the power assist device
r ... Object position (vector)
α ... Assist ratio (scalar)
DESCRIPTION OF SYMBOLS 10 ... Object 100 ... Power assist apparatus 111 ... Hari 112 ... Rail 121 ... X direction rod 122 ... Y direction rod 130 ... Z axis (ball screw)
140 ... Center base 141 ... Bearing (for x direction rod)
142… Bearing (for y-direction rod)
143 ... z-axis bearing female screw pipe 150 ... operation part 151 ... operation handle 152 ... hand 161 ... motor (for moving the x-direction rod)
162 ... motor (for y-direction rod movement)
163 ... Motor (for z-axis movement)
171 ... x-direction rod drive gear 172 ... x-direction rod drive shaft 173 ... x-direction rod drive belt 181 ... moving wheel (for x-direction rod movement)
182 ... Moving wheel (for y-direction rod movement)
200: Motor control device (control unit)
232 ... Force sensor M ... Motor E ... Encoder

Claims (5)

It has a force sensor that detects the operation force F _h the operator operating the object moving or the operation target to be attitude change, the operating force by the assist force A which is determined and output based on the operating force F _h in the power assist device for assisting a F _h,
Skilled experimenter, or embodied by the subject or the like, wherein such delivery route or the operating force F _h of the object, based on the sample data about the sample, have a assist force correction means for correcting the assist force A ,
The assist correction means corrects the assist force A according to a correction force that is a difference between an operator's operation and a sample data operation . Skilled experimenter, or is embodied by the subject or the like, such as conveying path or the operating force F _h of the object, in claim 1, characterized in that it comprises a sample data recording means for recording the sample data about the sample The power assist device described. 3. The power assist device according to claim 2, wherein the sample data recording unit records the position r on the transport route and the operation force F _h at every predetermined sampling period. The assist force correcting means includes
A transport route that is most similar to one of the transport route in the route record information related to the object that the operator has operated in the past, or the current transport route of the object that the operator is currently operating,
The similar transportation route selecting means for selecting from among the plurality of transportation routes in the sample data collected by sampling a plurality of times. Power assist device. The assist force correcting means includes
About the angle formed by the operation force of the expert at the position of the object closest to the current position of the object operated by the operator and the current operation force of the operator
When the angle exceeds a predetermined value, the assist force is obtained after replacing the current operation force of the operator with 0,
When the angle is equal to or less than a predetermined value, the assist force is obtained after replacing the current operation force of the operator with a weighted average of the current operation force of the operator and the operation force of the expert. The power assist device according to any one of claims 1 to 4.

Images