System for carrying an item

The item-carrying system comprises: a robot comprising: a gripping portion for gripping an item; external force detecting means for detecting an external force applied to the gripping portion; opening-degree detecting means for detecting an opening-degree of the gripping portion; autonomous movement means; and receiving/passing motion deciding means for deciding a motion of the robot in an item receiving/passing operation, wherein the receiving/passing motion deciding means comprises: means for determining to start receiving an item that causes the gripping portion to start a receiving motion if the external force detecting means has detected an external force not less than a first predetermined value, when the gripping portion is not gripping an item; and means for determining the completion of a receiving motion on the basis of at least one of an external force and an opening-degree during the receiving motion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention pertains to an item-carrying system using a robot that can move autonomously.

2. Description of the Related Art

In recent years, studies have been made to make an autonomously movable robot to carry an item. Such a robot makes motions of receiving/passing the item from/to a human when carrying the item, and therefore it is desired to control the robot to perform the motions without giving the human a sense of discomfort. A robot gripping control unit as disclosed in Japanese Patent Application Laid-Open (Kokai) No. 2004-167674 is for providing a control for a robot which is gripping an item and passes to a human.

However, the robot described in the above patent document has a disadvantage of being an art that mainly assumes a situation in which the robot gripping the item passes it to a human, and therefore the robot can possibly give the human a sense of discomfort that the robot is forcibly snatching the item.

The present invention is conceived to solve this problem, and aims to provide an item-carrying system that allows the robot to receive the item from the human without giving the sense of discomfort thereto.

SUMMARY OF THE INVENTION

To solve the above-mentioned problem, item1of the present invention provides an item-carrying system comprising: a robot comprising: a gripping portion for gripping an item and can open/close; external force detecting means for detecting an external force applied to the gripping portion; opening-degree detecting means for detecting an opening-degree of the gripping portion; and autonomous movement means; and receiving/passing motion deciding means for deciding a motion of the robot in an item receiving/passing operation, the system receiving/passing the item with the gripping portion, wherein the receiving/passing motion deciding means comprises: means for determining to start receiving an item that causes the gripping portion to start a receiving motion if the external force detecting means has detected an external force not less than a first predetermined value, when the gripping portion is not gripping an item; and means for determining the completion of a receiving motion that determines the completion of an item-receiving motion on the basis of at least one of an external force detected by the external force detecting means and an opening-degree detected by the opening-degree detecting means, during the receiving motion.

When passing an item to the robot, the human presses it against the gripping portion of the robot in a grippable manner. The external force detecting means detects the external force caused by the item, and the means for determining to start receiving an item determines, on the basis of the force level, to start and starts the receiving motion.

On judging that “the robot has received the item”, the human releases it, thus decreasing the external force to be detected by the external force detecting means. The system for carrying an item uses the decrease in the force to determine whether or not the robot has completed its receiving motion.

The system also determines the robot has completed its receiving motion when the opening degree of the gripping portion has decreased to an extent exceeding a predetermined amount.

Being capable of determining whether or not it is possible to start the receiving motion, and of recognizing the completion of the motion, the system can perform the receiving motion without giving the human a sense of discomfort.

According to item2of the present invention, there is provided an item-carrying system as set forth in item1, wherein the means for determining the completion of a receiving motion determines that the receiving motion has completed if the external force is not more than a second predetermined value.

Thus, setting the second predetermined value for the external force and using the value to determine the completion of the receiving motion facilitates determining the completion of the receiving motion.

According to item3of the present invention, there is provided an item-carrying system as set forth in item1, wherein the means for determining the completion of a receiving motion determines that the receiving motion has completed if the opening degree is not more than a third predetermined value.

Thus, setting the third predetermined value for the opening degree and using the value to determine the completion of the receiving motion facilitates determining the completion of the receiving motion.

According to item4of the present invention, there is provided an item-carrying system as set forth in item1, wherein the receiving/passing motion deciding means causes the gripping portion to generate a gripping force if the means for determining the completion of a receiving motion has determined that the receiving motion has completed.

Thus, by gripping the item after the completion of the receiving motion, the robot avoids giving the human a sense of discomfort such as forcibly snatching the item therefrom.

According to item5of the present invention, there is provided an item-carrying system as set forth in item4, wherein the system further comprises means for determining success/failure in gripping an item after the receiving/passing motion deciding means caused the gripping portion to generate a gripping force.

This construction allows determining whether or not the gripping portion has successfully gripped the item.

According to item6of the present invention, there is provided an item-carrying system as set forth in item5, wherein the means for determining success/failure in gripping an item determines the success/failure of the gripping motion if the opening degree is not more than a fourth predetermined value.

To prevent failing in gripping a thin item, the robot can determine success/failure in gripping the item, only when the opening degree is not more than the fourth predetermined value. This permits omitting to determine the success/failure when the item is thick.

According to item7of the present invention, there is provided an item-carrying system as set forth in item5, wherein the receiving/passing motion deciding means reperforms the receiving motion if the means for determining success/failure in gripping an item has determined that the gripping motion is failed.

This allows the robot to re-receive the item when failing to grip the item.

According to item8of the present invention, there is provided an item-carrying system as set forth in item5, wherein the robot comprises a pair of gripping portions for gripping an item.

According to item9of the present invention, there is provided an item-carrying system as set forth in item8, wherein the means for determining success/failure in gripping an item determines success/failure of the gripping motion on the basis of an external force generated from the item when the pair of gripping portions are moved closer or apart.

This permits the robot to determine whether or not both of the gripping portions are gripping the item.

According to item10of the present invention, there is provided an item-carrying system as set forth in item9, wherein the means for determining success/failure in gripping an item determines the gripping motion as success or failure, if the external force is not less than or less than a fifth predetermined value, respectively, the external force being generated from the item when the pair of gripping portions are moved closer or apart and detected by the external force detecting means.

According to item11of the present invention, there is provided an item-carrying system as set forth in item1, wherein the gripping portion comprises:

a palm portion;

a first finger attached to the palm portion via a first joint; and

a second finger attached to the palm portion via a second joint, the gripping portion gripping an item with the first and the second fingers, and wherein

the opening-degree detecting means comprises:

first finger angle detecting means for detecting a first finger angle between the palm and the first finger; and

second finger angle detecting means for detecting a second finger angle between the palm and the second finger.

This allows detecting the opening degree with a simple construction.

According to item12of the present invention, there is provided an item-carrying system as set forth in item1, wherein the external force detecting means can detect a horizontally directed external force, and wherein the receiving/passing motion deciding means uses a horizontally directed external force applied to the gripping portion as an external force from the item.

This eliminates an effect of the external force due to the self-weight of the item, and allows detecting and using in a preferable manner an external force due to receiving/passing an item from/to the human.

According to item13of the present invention, there is provided an item-carrying system as set forth in item12, wherein the external force detecting means is a six-axis force sensor.

This permits a simple construction to detect the horizontally directed external force.

According to item14of the present invention, there is provided an item-carrying system as set forth in item1, wherein the system further comprises: human-position specifying means for specifying the position of a human; and receiving/passing position deciding means for deciding, on the basis of the specified human-position, the position for the robot to receive/pass an item from/to the human, and then moving the robot to the receiving/passing position.

The robot thus moves to a preferred position for the receiving/passing motion, thereby alleviating the load for the human in receiving/passing the item.

According to item15of the present invention, there is provided an item-carrying system as set forth in item1, wherein the system further comprises: body-height specifying means for specifying the body-height of the human; and receiving/passing height deciding means for deciding, on the basis of the specified human-body height, the height for the robot to receive/pass an item from/to the human, and then moving the gripping portion to the receiving/passing height.

The robot thus holds the gripping portion to a preferred height for the human to receive/pass the item, thereby ridding the human of the load therefor.

According to item16of the present invention, there is provided an item-carrying system as set forth in item1, wherein the system comprises human-specifying means for specifying the human to whom to pass the item, on the basis of a task instruction signal.

This prevents the robot from erroneously recognizing the human who is to pass the item to the robot.

As discussed above, the present invention can provide the item-carrying system in which a robot can perform the item-receiving motion without giving the human a sense of discomfort when receiving it from the human.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Hereinafter, referring to the drawings accordingly, an embodiment of the present invention or an item-carrying system will be discussed, considering an office as a task-performing area and taking a robot control system adapted for item-carrying operation therein. In the drawings, the same portions are attached with the same symbol and a redundant explanation thereof will be omitted.

The “opening degree” as used herein is an index (value) to indicate an opening level of the gripping portion, such as the distance between the fingers of the gripping portion and the angle between a finger portion and a palm portion of the gripping portion.

<Construction of Robot Control System A>

First, a robot control system A according to an embodiment of the invention will be described.FIG. 1is a system block diagram showing a robot control system according to an embodiment of the present invention.

As shown inFIG. 1, the robot control system A comprises: at least one robot R (one in this embodiment) placed in the task-performing area EA; a base station1(such as a wireless LAN) connected to the robot A via wireless communication; a robot managing unit3(such as a server) connected to the base station via a router2; a terminal5connected to the robot managing unit3via a network4; and a sensing tag T worn by a sensing object (a human).

The robot R is positioned in the task-performing area EA, in which the robot R autonomously moves to implement a task (carrying an item) on the basis of a task instruction signal. In the task-performing area EA is provided an item storage site B1, in which the robot R can place the item if, for example, the robot has failed to find the human who is to pass the item thereto.

To make the robot R operate a task based on task data to be input from the terminal5(to be described below), the robot managing unit3generates and outputs a task instruction signal including the task content to the robot R. The task data pertains to the task for the robot R to operate, which contains, for example, the human who is to pass the item to the robot R, the human to whom the robot R is to pass the item, and type of item for carriage.

The terminal5is an input device, such as a desk-top computer and a PHS from which to input the task data to the robot managing unit3. The terminal5is also an output (display) device to enable the human to check a motion reporting signal (task completion reporting signal) sent from the robot R.

Next, the robot R according to the present embodiment will be described. In the description, X, Y, and Z axes are provided in forward-backward, left-right, and up-down directions, respectively (seeFIG. 2).

The robot R according to the embodiment is a dual-legged autonomous moving robot that implements a task based on the instruction signal sent from the robot managing unit3.

FIG. 2is a side view showing an appearance of the robot inFIG. 1. As shown inFIG. 2, the robot R comprises a body R2, a head R4, two arms R3(only one is shown) and two legs R1(only one is shown) with which to stand up and autonomously move (e.g., walks and runs), like the human. The robot R also has on the back of the body R2(in the form of carrying on the shoulders) a controller mounting portion R5for controlling the operations of the legs R1, the body R2, the arms R3, and the head R4.

<Driving Structure of Robot R>

With reference toFIG. 3, a driving structure of the robot R will be described.FIG. 3is a perspective view showing in a simplified manner a driving structure of the robot inFIG. 1. Joints as shown inFIG. 3are illustrated as electric motors for driving the joints.

As shown inFIG. 3, the legs R1each comprise six joints11R (L)-16R (L), totaling in twelve joints in both right and left sides. These joints include: hip joints11R,11L for rotating (around the Z axis) the legs attached to the hip (connections between the legs R1and the body R2); hip joints12R,12L around the pitch (Y) axis at the hip; hip joints13R,13L around the roll (X) axis at the hip; knee joints14R,14L around the pitch (Y) axis at the knee; ankle joints15R,15L around the pitch (Y) axis at the ankle; and ankle joints16R,16L around the roll (X) axis at the ankle. At the bottom of the legs R1, L1are attached with feet17R,17L, respectively. Note that R and L indicate the right and left sides, respectively, and will be omitted in some cases hereinafter.

The legs R1comprise: the hip joints11R(L),12R(L),13R(L); the knee joint14R(L); and the ankle joints15R(L),16R(L). The hip joints11R(L)-13R(L) and the knee joint14R(L) are connected via thigh links51R,51L, and the knee joints14R(L) and the ankle joints15R(L),16R(L) via shank links52R,52L.

As shown inFIG. 3, the body R2has the legs R1, the arms R3, and the head R4connected thereto. That is, the body R2(body link53) is connected to the legs R1, the arms R3, and the head R4via the hip joints11R(L)-13R(L), shoulder joints31R(L)-33R(L) (to be described later), and neck joints41,42(to be described later), respectively.

The body R2also has a joint21for rotation thereof around the Z axis.

As shown inFIG. 3, the arms R3in the right and left sides each comprise seven joints31R(L)-37R(L), totaling in fourteen joints. These joints include: shoulder joints31R,31L around the pitch (Y) axis at the shoulders (connections between the arms R3and the body R2); shoulder joints32R,32L around the roll (X) axis at the shoulders; shoulder joints33R,33L for rotating the arms (around the Z axis); elbow joints34R,34L around the pitch (Y) axis at elbows; arm joint35R,35L for rotating wrists (around the Z axis); wrist joints36R,36L around the pitch (Y) axis of the wrists; and wrist joints37R,37L around the roll (X) axis of the wrists. The arms R3each have on their ends a gripping portion (hand)71R,71L, respectively, attached thereto.

That is, the arms R3comprise: the shoulder joints31R(L),32R(L),33R(L); the elbow joints34R(L); the arm joint35R(L); and the wrist joints36R(L),37R(L). The shoulder joints31R(L)-33R(L) and the elbow joints34R(L) are connected via an upper arm link54R(L), and the elbow joints34R(L) and the wrist joints36R(L),37R(L) via a forearm link55R(L).

The head4comprises: a neck joint41around the Y axis of the neck (connection between the head R4and the body R2); and a neck joint42around the Z axis of the neck, as shown inFIG. 3. The neck joints41and42are provided for setting tilt and panning angles, respectively, of the head R4.

With this construction that provides the both legs R1with a total of twelve freedoms of movement, the robot can arbitrarily move in a three-dimensional space by driving each of the twelve joints11R(L)-16R(L) in an appropriate angle to allow a desired motion of the legs R1when moving. Also, with the arms R3provided with a total of fourteen freedoms of motion, the robot R can perform a desired operation by driving each of the fourteen joints31R(L)-37R(L) in an appropriate angle.

Between the ankle joints15R(L),16R(L) and the feet17R(L), a known six-axis force sensor61R(L) is provided. The six-axis force sensor61R(L) senses three directional components Fx, Fy, Fz and three directional components Mx, My, Mz of the moment of a reaction-force applied to the robot R from the floor surface.

Between the wrist joints36R(L),37R(L) and the gripping portions71R(L), the known six-axis force sensor62R(L) is provided. The known six-axis force sensor62R(L) senses three directional components Fx, Fy, Fz and three directional components Mx, My, Mz of the moment of a reaction-force applied to the gripping portions38R(L) of the robot R.

The body R2has an inclination sensor63for sensing an inclination with respect to the gravitational (Z) axis of the body R2and an angular velocity thereof.

The electric motors at the joints each cause a displacement to, for example, the thigh links51R(L) and the shank links52R(L), via a deaccelerator (not shown) for decreasing and increasing the power of the motor. Each angle of the joints is detected by a joint angle detecting means (e.g., a rotary encoder).

The controller mounting portion R5includes: an autonomous movement controlling section150(to be discussed later); a gripping portion controlling portion160; a wireless communication portion170; a main controlling portion200; and a battery (not shown). Detection data from the sensors61-63is sent to the controlling sections in the controller mounting portion R5. The controlling sections each send a drive instruction signal to drive the electric motor.

FIG. 4is a block diagram showing the robot inFIG. 1. In addition to the legs R1, the arms R3, and the head R4, the robot R comprises: cameras C, C; a speaker S; microphones MC, MC; an image processing section100; a sound processing section110; an object sensing portion120; the autonomous movement controlling section150; the gripping portion controlling portion160; the wireless communication portion170; the main controlling portion200; and a memory portion300, as shown inFIG. 4.

The robot R also comprises a gyro-sensor SR1and a GPS receiver SR2which detect data pertaining to the direction (direction data) and the position (position data) of the robot R, respectively. The data detected by the gyro-sensor SR1and the GPS receiver SR2is output to the main controlling portion200for use to determine the motion of the robot R, and then sent to the robot managing unit3from the main controlling portion200via the wireless communication portion200.

The cameras C, C, e.g., color CCD (Charge-Coupled Device) cameras, can each capture an image as digital data. The cameras C, C are arranged side by side in parallel and each take an image which is output to the image processing section100. The cameras C, C, the speaker S, and the microphones MC, MC are all mounted in the head R4.

The image processing section100is a portion for processing an image taken by the cameras C, C to grasp therefrom the situation around the robot so as to recognize an obstacle or a human around the robot R. The image processing section100comprises a stereo processing portion101, a moving-object extraction portion102, and a face recognition portion103.

The stereo processing portion101conducts the steps of performing pattern-matching between the images taken by both sides of the cameras C, C using one of the images as a reference image; generating a parallax image by calculating parallax between corresponding pixels in the images; and outputting the generated parallax and original images to the moving-object extraction portion102. This parallax represents the distance from the robot R to the pictured object.

The moving-object extraction portion102extracts a moving object in the pictured image based on the data output from the stereo processing portion101. The moving object is extracted for the purpose of recognizing a human, with the assumption that any moving object is a human.

In order to extract a moving object, the moving-object extraction portion102has several past frames stored therein with which latest frames (images) are compared to perform pattern-matching, calculate a moving amount for each pixel, and generate an image representing the amount of movement. When there exists in the parallax and moving amount images any pixel with a large moving amount in a predetermined distance range from the cameras C, C, the extraction portion102assumes a human exists at that position, extracts the moving object as a parallax image dedicated for the predetermined range, and then outputs an image of the object to the face recognition portion103.

The moving-object extraction portion102also calculates and outputs the height of the extracted object or the body height to the face recognition portion103.

That is, the moving-object extraction portion102, as an example of human-position specifying means as described in the claims, can specify the position of the human with respect to the robot R.

Also, the moving-object extraction portion102, as an example of body-height specifying means as described in the claims, can calculate the human body height.

The face recognition portion103extracts a portion with a skin color from the extracted moving object to recognize the face position from, for example, the size and shape thereof. Similarly, the hand position is also recognized on the basis of, for example, the area, size, and shape of the skin color portion.

The face position recognized is output to the main controlling portion200as well as to the wireless communication portion170to be sent to the robot managing unit3via base station1, as information for the robot R to move and communicate with the human.

The speaker S outputs a sound on the basis of sound data created by a sound synthesizing portion111(to be discussed later).

The microphones MC, MC collect sound around the robot R. The collected sound is output to a sound recognizing portion112and a sound source localizing portion113(to be discussed later).

The sound processing section110includes the sound synthesizing portion111, the sound recognizing portion112, and the sound source localizing portion113.

The sound synthesizing portion111creates a sound data from character information on the basis of a speech behavior instruction determined and output by the main controlling portion200, and outputs the sound to the speaker S. The sound data is created by using a correspondence relationship between prestored character information and sound data.

The sound recognizing portion112receives sound data input from the microphones MC, MC, and creates and outputs to the main controlling portion200, character information from the sound data on the basis of a prestored correspondence relationship between sound data and character information.

The sound source localizing portion113specifies the position of the sound source (the distance and direction from the robot R) on the basis of the differences in sound pressure and time-of-arrival of sound between the microphones MC, MC.

Next, with reference toFIGS. 5-8, the object sensing portion120shown inFIG. 4and the sensing tag T will be discussed.FIG. 5is a block diagram showing the object sensing portion inFIG. 4.FIG. 6is a block diagram showing the sensing tag inFIG. 1.FIGS. 7A and 7Bare illustrative views of a search area for the object sensing portion, presented in top and side views, respectively.FIG. 8is an illustrative view of partitioning of areas around the robot by the object sensing portion.

The object sensing portion120senses whether or not a sensing object H wearing the sensing tag T exists around the robot R, and if so, specifies the position of the object H.

As shown inFIG. 5, the object sensing portion120comprises a control means121, a radio wave sending/receiving means122, an irradiating means123, and a memory means124.

The control means121creates a search signal to be wirelessly sent from the radio wave sending/receiving means122(to be discussed later), and a direction checking signal to be output from the irradiating means123(to be discussed later) as infrared light, as well as specifies the position of the sensing object H on the basis of a reception acknowledgement signal sent from the sensing tag T that has received the search signal.

Here, it is to be noted that: the search signal is used to sense whether or not the sensing object H exists around the robot R; the direction checking signal to sense to which direction the sensing object H will move with the robot R provided as a reference; and the reception acknowledgement signal to indicate that the sensing tag T has received at least the search signal.

The control means121comprises a data processing portion121a, a coding portion121b, a time division portion121c, a decoding portion121d, and an electric field strength detecting portion121e.

The data processing portion121acreates a search signal and a direction checking signal, specifies the position of the sensing object H, and comprises a signal generating portion121a1and a position specifying portion121a2.

The signal generating portion121a1refers to the memory portion124at every predetermined time period or at every input of a signal (transmission instruction signal) instructing a transmission of an electric signal from the main controlling portion200, to obtain an identification number (hereinafter referred to as a robot ID) unique to the robot R in which is provided the object sensing portion120.

The signal generating portion121a1produces a search signal including the robot ID and a reception acknowledgement request signal.

Here, it is to be noted that the reception acknowledgement request signal is for requesting the sensing object H (sensing tag T) that has received the search signal to generate a signal indicating the reception of the search signal (reception acknowledgement signal).

Further, when generating this search signal, the signal generating portion121a1also generates a direction checking signal to be irradiated from the irradiating means123(to be discussed later) as an infrared signal.

The direction checking signal is individually generated for all of the irradiating portions (LED1-LED8) provided to the irradiating means123, and includes the robot ID and an identifier to specify each of the irradiating portions (Irradiating Portion ID).

The direction checking signal is also generated when the reception acknowledgement signal input from the decoding portion121d(to be described later) includes an irradiation request signal.

In the present embodiment employing a total of eight irradiating portions, the data processing portion121agenerates a total of eight direction checking signals each including the robot ID and the irradiating portion ID.

For example, when the robot ID is “02” and the irradiating portions (LED1-LED8) respectively have the irradiating portion IDs (L1-L8), the direction checking signals to be generated for the irradiating portions LED1and LED2, respectively, include a robot ID=“02” and an irradiating portion ID=“L1”, and a robot ID=“02” and an irradiating portion ID=“L2”, respectively.

The signal producing portion121a1outputs the direction checking signal and the search signal to the coding portion.

The position specifying portion121a2specifies the position of the sensing object H on the basis of the reception acknowledgement signal sent from the sensing tag T that has received the search signal. The processes to be conducted at this time in the position specifying portion121a2will be discussed in detail later together with those processes in decoding portion121dand the electric field strength detecting portion121e.

The coding portion121bcodes and then outputs a signal that was input thereto, i.e., outputs a search signal obtained by coding (a coded search signal) to the radio wave sending/receiving means122(to be described below).

With this, the coded search signal is modulated and then wirelessly sent from the radio wave sending/receiving means122.

The coding portion121bsimilarly codes the direction checking signal that was input from the data processing portion121a, and then outputs the coded direction checking signal thus obtained to the time division portion121c(to be discussed below).

In this embodiment, one direction checking signal is generated in the data processing portion121afor each irradiating portion of the irradiating means123.

The irradiating means123is provided with a total of eight irradiating portions as shown inFIG. 5, and therefore, a total of eight direction checking signals are input to the coding portion121bfrom the data processing portion121a.

As a result, a total of eight coded direction checking signals are generated in the coding portion121band output to the time division portion121c.

The time division portion121csets the irradiation order and timing for the irradiating portions (LED1-LED8) of the irradiating means123.

Specifically, on input of the coded direction checking signal from the coding portion121b, the time division portion121csets the irradiation order and timing for the irradiating portions (LED1-LED8), and then outputs the coded direction checking signal to the irradiating means123according to the determined order and timings.

For example, in order to flash the irradiating portions at an time interval of 0.5 second in the order of LEDs1,4,7,2,5,8,3and6, the time division portion83outputs the coded direction checking signal to modulating portions of the LEDs1,4,7,2,5,8,3and6in this order at an time interval of 0.5 second.

In the present embodiment, a total of eight coded direction checking signals are input to the time division portion121c. The coded direction checking signals are each predetermined in the data processing portion121ain terms of to which irradiating portion to be output.

Thus, on receiving inputs of the coded direction checking signals, the time division portion121cchecks each of the irradiating portion IDs contained in the signals, and then outputs the signals in a predetermined order and timing to modulating portions adjacent to the irradiating portions specified by the irradiating portion IDs.

For example, when the irradiating portions (LED1-LED8) have IDs specified as “L1-L8”, the time division portion121coutputs the coded direction checking signals respectively having the irradiating portion IDs “L1” and “L2” to the modulating portions adjacent to the irradiating portions LED1and LED2, respectively.

The irradiating means123irradiates light to a search area preset around the robot R.

The irradiating means123comprises the plurality of irradiating portions LED1-LED8and the modulating portions provided corresponding to the irradiating portions.

The modulating portions modulate with a predetermined modulation method the coded direction checking signals input from the time division portion121cinto modulated signals.

The irradiating portions irradiate the modulated signals to the predetermined search area as infrared signals (lights).

In the present embodiment, in order to specify the position of the sensing object H, the area around the robot R is partitioned into a plurality of search areas (seeFIG. 7A). For each search area, one LED is provided an as an irradiating portion for irradiating an infrared light thereto.

Specifically, in the example shown inFIG. 7A, a total of eight search area D1-D8are set in the whole circumference or 360 degrees around the robot R.

In other words, a plurality of search areas D1-D8each with an approximate sector shape are provided around and encircling the robot R. The robot R is located approximately at the center area surrounded by the sector areas.

Thus, in an example shown inFIG. 7, in order to allow irradiation of an infrared light to each search area, the robot R has in the head R3a total of eight irradiating portions along the periphery of the head R3, each directed to a corresponding search area.

Also, as shown inFIG. 7A, the search areas D1-D3in the front side of the robot R are made narrower than the other search areas D4-D8.

Thus, the search area D1-D8are provided in order to solve the problem that the sensing object H may think the lines of vision of the robot R are not directed thereto, if a deviation occurs between the front of the face of the robot R (referred to as the direction of the lines of vision) and the position of the sensing object H when the robot R senses the sensing object H and directs its face thereto.

Here, a method for eliminating the problem is to increase the number of the search areas, but only on the front side rather than the whole circumference of the robot R, to allow finely specifying a position on the front side, so that the lines of vision of the robot R can be directed to the position of the sensing object H. This construction can also decrease the number of the irradiating portions.

Thus in the present embodiment, by narrowing the irradiation scope of the infrared light in the search area D1-D3on the front side of the robot R, it is made possible to more accurately specify the position of the sensing object H in the search areas D1-D3.

This allows, when the sensing object H is a human and the cameras C, C take an image of the face, more accurately specifying the position of the sensing object H on the front side of the robot R, and reflecting the result on the movement control of the robot R and image angle adjustment. As a result, the cameras C, C can be precisely directed to the face of the sensing object H.

As shown inFIG. 5, the radio wave sending/receiving means122sends a radio wave to the areas around the robot R, as well as receives the reception acknowledgement signal sent from the sensing object H that has received the radio wave.

The radio wave sending/receiving means122comprises a modulating portion122a, a demodulating portion122b, and a sending/receiving antenna122c.

The modulating portion122amodulates with a predetermined modulation method the search signal (actually, the coded search signal) input from the data processing portion121ainto a modulated signal, and then wirelessly sends this signal via the sending/receiving antenna122c.

The demodulating portion122breceives, via the sending/receiving antenna122c, the modulated signal wirelessly sent from the sensing tag T of the sensing object H, and demodulates the received signal to obtain the reception acknowledgement signal (actually, a coded reception acknowledgement signal).

The demodulating portion122bthen outputs the obtained reception acknowledgement signal to the decoding portion121and the electric field strength detecting portion121d.

The decoding portion121ddecodes the coded reception acknowledgement signal to obtain the reception acknowledgement signal, and outputs the obtained signal to the data processing portion121a.

In the present embodiment, the reception acknowledgement signal includes at least the irradiating portion ID, the robot ID, and a tag ID number (as will be discussed in detail later), which are output to the data processing portion121aby the decoding portion121d.

The irradiation request signal included in the reception acknowledgement signal is also output to the data processing portion121a.

The electric field strength detecting portion121eis for obtaining the strength of the modulated signal sent from the sensing tag T of the sensing object H, which is received by the radio wave sending/receiving means122.

Specifically, the electric field strength detecting portion121edetects the electric power of the reception acknowledgement signal input from the demodulating portion122b, obtains an average value of the power as the electric field strength, and then outputs the strength to the data processing portion121a.

The position specifying portion121a2of the data processing portion121ais for specifying the position of the sensing object H.

Specifically, the position specifying portion121a2obtains the direction from the robot R to the sensing object H on the basis of the electric field strength of the modulated signal, when the radio wave sending/receiving means122receives the modulated signal sent from the sensing tag T. The position specifying portion121a2further refers to the irradiating portion ID contained in the reception acknowledgement signal to specify from which irradiating portion the light received by the sensing target H was irradiated, and regards the specified irradiation direction of the irradiating portion, i.e., the direction of the search area corresponding to the irradiating portion, as the direction in which the sensing target H exists, so as to specify the position of the sensing object H.

In this embodiment, the position specifying portion121a2first obtains a robot ID out of the reception acknowledgement signal that was input from the decoding portion121dand compares the robot ID with a robot ID stored in the memory means124. If both the IDs match, then the position specifying portion121a2begins specifying the position of the sensing target H.

In the embodiment, the surrounding area of the robot R is partitioned to four areas depending on the distance from the robot R, i.e., defined as areas D11, D12, D13, and D14in the order of shorter distance from the robot, as shown inFIG. 8.

Each of these areas and the electric field strength are associated to each other in advance based on the magnitude of the strength, and a table (distance table) indicating the associations is stored in the memory means124.

The position specifying portion121a2thus refers to the distance table on the basis of the electric field strength input from the electric field strength detecting portion124, to obtain (area) information indicating in which area the sensing object H that sent the reception acknowledgement signal is present.

For example, the position specifying portion121a2obtains (area) information that indicates the area D13, if the electric field strength input thereto from the electric field strength detecting portion121efalls between the threshold values defining the area D13.

Further, the position specifying portion121a2refers to the irradiating portion ID contained in the reception acknowledgement signal input from the decoding portion121d, to specify from which irradiating portion in the irradiating means123was the light irradiated that was received by the sensing object H that had sent the reception acknowledgement signal, so as to obtain (direction) information indicating the irradiation direction of the specified irradiating portion.

In the present embodiment, in the surrounding area of the robot R, a total of eight searching areas D1-D8are set around the robot R, as shown inFIG. 7A.

In the memory means124is stored a (direction) table indicating to which search area the irradiating portions are each directed.

Thus, the data processing portion121auses the irradiating portion ID to refer to the direction table stored in the memory means124, to check to which of the predetermined search areas D1-D8the infrared light is irradiated which is radiated from the irradiating portion with the irradiating portion ID. The data processing portion121athen obtains information indicating the confirmed search area as (direction) information indicating the direction in which the sensing object H exists.

The position specifying portion121a2generates (position) information indicating the position of the sensing object H from the obtained area information and direction information.

As a result, the positional relationship between the robot R and the sensing object H is specified from the strength of the reception acknowledgement signal received by the robot R and the irradiating portion ID contained in the reception acknowledgement signal. In other words, the direction and the distance from the sensing object H in which the robot R exists, i.e., the position of the sensing object H, are specified.

The position specifying portion121a2outputs the position information to the main controlling portion200along with the tag ID number contained in the reception acknowledgement signal input from the decoding portion121d.

This allows the main controlling portion200to control the autonomous movement controlling section150to move the robot R to the front of the sensing subject H, and if the sensing subject H is a human, to correct the elevation angle and direction of the cameras C, C to take an image of the face of the sensing subject H.

When the reception acknowledgement signal contains the irradiation request signal, the signal producing portion121a1generates and outputs the direction checking signal to the coding portion121b. This causes the irradiating portions of the irradiating means123to radiate infrared light.

The sensing tag T is for receiving the radio wave sent and light irradiated from the robot R and sending thereto the reception acknowledgement signal for acknowledging the reception of the wave and light.

The radio wave sent and the light irradiated from the robot R are received by the sensing tag T worn by the sensing object H which is a human in this embodiment. The sensing tag T is described below.

As shown inFIG. 6, the sensing tag T comprises a radio wave sending/receiving means125, a light receiving means126, a reception acknowledgement signal generating means127, and a memory means128.

The radio wave sending/receiving means125is for receiving the modulated signal wirelessly sent from the robot R, as well as modulating and then sending to the robot R the reception acknowledgement signal generated by the reception acknowledgement signal generating means127(to be discussed later).

The radio wave sending/receiving means125comprises a sending/receiving antenna125a, a demodulating portion125b, and a modulating portion125c.

The demodulating portion125bis for demodulating the modulated signal sent from the robot R and received via the sending/receiving antenna125a, obtaining the search signal (actually, a coded search signal), and outputting the search signal to the reception acknowledgement signal generating means127(to be described later).

The modulating portion125cis for modulating the coded reception acknowledgement signal which was input from a coding portion127cof the reception acknowledgement signal generating means127to generate a modulated signal, as well as for wirelessly sending the modulated signal via the sending/receiving antenna125a.

The light receiving means126is for receiving the infrared light irradiated from the robot R.

The light receiving means126comprises a light receiving portion126aand a light demodulating portion126b.

The light receiving portion126adirectly receives the infrared light (signal) irradiated from the robot R.

The light demodulating portion126bdemodulates the infrared signal received by the light receiving portion to obtain the direction checking signal (actually, the coded direction checking signal).

Specifically, on receiving the infrared light irradiated from the robot R with the light receiving portion126a, the light receiving means126demodulates the received infrared signal with the light demodulating portion126bto obtain the coded direction checking signal, and then outputs the signal to the reception acknowledgement signal generating means127.

When the radio wave sending/receiving means125has received a search signal sent from the robot R, the reception acknowledgement signal generating means127generates, according to the reception acknowledgement request signal contained in the signal, the reception acknowledgement signal for indicating the reception of the search signal sent from the robot R.

The reception acknowledgement signal generating means127comprises a decoding portion127a, a data processing portion127b, and a coding portion127c.

The decoding portion127adecodes a coded signal that was input thereto to obtain a signal.

The decoding portion127adecodes the coded search signal input from the radio wave sending/receiving means125and the coded direction checking signal input from the light receiving means126, to obtain the search signal and the direction checking signal. The decoding portion127athen outputs the search and direction checking signals to the data processing portion127bin the subsequent stage.

The data processing portion127bis for generating the reception acknowledgement signal.

In the present embodiment, the search signal includes: the robot ID which is an identifier for specifying the robot R that has sent the search signal; and the reception acknowledgement request signal that instructs the sensing object H which has received the radio wave to conduct a predetermined process.

The direction checking signal contains: the robot ID which is an identifier for specifying the robot R that has sent the direction checking signal; and the irradiating portion ID for specifying the irradiating portion that has sent the direction checking signal.

Thus, on receiving an input of the search signal, the data processing portion127bswitches the light receiving means126from the wait to activated states according to the reception acknowledgement request signal contained in the search signal.

Then, if the direction checking signal is input to the light receiving means126within a predetermined time period after the activation thereof, the data processing portion127bcompares the robot IDs contained in the direction checking signal and the search signal.

If the IDs match, the data processing portion127brefers to the memory means128to obtain a unique (tag) ID number assigned to the sensing tag T.

The data processing portion127bthen generates and outputs to the coding portion127c, the reception acknowledgement signal that includes the tag ID number, the robot ID contained in the search signal, and the irradiating portion ID contained in the direction checking signal.

In contrast, if no direction checking signal is input to the light receiving means126within a predetermined time period after the activation thereof, or if the robot IDs contained in the search signal and the direction checking signal do not match, the data processing portion127bgenerates and then outputs to the coding portion127c, the reception acknowledgement signal that further contains the irradiation request signal.

Here, the irradiation request signal is a signal for instructing the robot R as a sensing unit to irradiate the infrared light.

The coding portion127ccodes and then outputs to the radio wave sending/receiving means125, the reception acknowledgement signal input thereto into the coded reception acknowledgement signal.

By this procedure, the coded reception acknowledgement signal is modulated by the modulating portion125c, and then wirelessly sent via the sending/receiving antenna125a.

As shown inFIG. 4, the autonomous movement controlling section150comprises a head controlling portion151, an arm controlling portion152, and a leg controlling portion153.

The head controlling portion151, the arm controlling portion152, and the leg controlling portion153drive the head R4, the arms R3, and the legs R1, respectively, under the instruction by the main controlling portion200. A combination of the autonomous movement controlling section150, the head R4, the arms R3, and the legs R1provides an example of the “autonomous movement means (autonomous movement unit)” as discussed in the claims.

The gripping portion controlling portion160drives the gripping portion71under the instruction by the main controlling portion200.

The wireless communication portion170is a communication unit for sending/receiving data to/from the robot managing unit3. The wireless communication portion170comprises a public network communication unit171and a wireless communication unit172.

The public network communication unit171is a wireless communication means using a public network such as a cellphone network and a PHS (Personal Handyphone System) network. While the wireless communication unit172is a wireless communication means using a short-distance wireless communication such as a wireless LAN complying with the IEEE802.11b standard.

The wireless communication portion170selects either the public network communication unit171or the wireless communication unit172according to a connection request from the robot managing unit3to perform data communication therewith.

Referring toFIGS. 9-11, the gripping portions71R (L) of the robot R will be described in further detail below.FIGS. 9 and 10are perspective views showing the gripping portion of the robot wherein the fingers are opened and closed, respectively.FIG. 11is a block diagram showing the gripping portion, the opening-degree detecting means, and the six-axis force sensor of the robot. The pair of gripping portions71R,71L are mirror-symmetrical, and only the left gripping portion71L is shown inFIGS. 9 and 10. In the discussion below, the gripping portions will be attached with numerical symbols without R and L in some cases.

As shown inFIGS. 9 and 10, the gripping portion71comprises a palm72, a first finger73, and second fingers7.

The palm72is connected to the forearm link55via the wrist joints36,37(seeFIG. 3).

The first finger73is the portion corresponding to the thumb and is connected to the bottom end side of the palm72via a first finger joint73a.

The second fingers74are the portions corresponding to the index, middle, ring, and little fingers, and are each connected to the end side of the palm72via a second finger joint74a.

In the palm72are mounted a first finger motor73bfor driving the first finger73and a second finger motor74bfor driving the second fingers74. In the palm72are also mounted a first finger angle detecting means83for detecting the first finger angle α (between the first finger73and the palm72); and a second finger angle detecting means84for detecting the second finger angle β (between the second fingers74and the palm72), as shown inFIG. 11.

The first finger angle α is formed by the first finger73and the palm72and becomes larger from the opened to closed states of the fingers. The first finger angle α is α1and α2(α1≦α≦α2) when the fingers are opened and closed, respectively, as shown inFIGS. 9 and 10.

The second finger angle β is formed by the second fingers74and the palm72and becomes larger from the opened to closed states of the fingers. The second finger angle β is β1(=0) and β2(0≦β≦β2) when the fingers are opened and closed, respectively, as shown inFIGS. 9 and 10.

Here, as a value for the opening degree of the gripping portion71, gripping angle deviation θ with respect to the first finger angle α and the second finger angle β is defined as follows.
θ=(α2−α)+(β2−β)

That is, the gripping angle deviation θ is a value representing the opening degree with respect to the fully opened state of the gripping portion71. The value becomes the minimum: θmin=0 and the maximum: θmax=α2+β2when the fingers are closed and opened, respectively.

When the gripping portion71is gripping an item, the gripping angle deviation θ has a positive value because the fingers73,74come to a stop before turning to the closed state. The gripping angle deviation θ has characteristics of becoming larger as the item to be gripped becomes thicker.

The robot control system A of the present embodiment employs the six-axis force sensor62as the means for detecting the external force applied from the item to the gripping portion71. The six-axis force sensor62can also detect the directions of the external force, and thus forces Fx, Fy, and Fz in the directions of X, Y, and Z axes out of the forces applied to the gripping portion71. Therefore, even when the item is heavy, it is possible to eliminate the force in the Z axis direction due to the gravitation of the item, and detect the external force (Fx in this embodiment) caused by the human in passing or receiving the item to/from the robot.

Now, with reference toFIG. 12, the main controlling portion200and memory portion300ofFIG. 4will be discussed.FIG. 12is a block diagram showing the main controlling portion and the memory portion inFIG. 4.

As shown inFIG. 12, the memory portion300comprises a human data memory portion310, a map data memory portion320, an item data memory portion330, and a speech data memory portion340.

The human data memory portion310stores data (human data) pertaining to the humans present in the office or the task-performing area EA, the data being associated to each other.

The human data includes, for example, human ID number, name, department name, tag ID number, place where the human is usually present, desk position, face image.

The map data memory portion320stores data (map data) relating to the layout in the task-performing area EA, such as positions of walls and desks.

The item data memory portion330stores data (item data) pertaining to the items for the robot R to carry, the data being associated to each other.

The item data includes, for example, ID number, name, size, and weight of the items.

The speech data memory portion340stores data (speech data) for the robot R to utter. <Main Controlling Portion>As shown inFIG. 12, the main controlling portion200comprises a motion management means210, a human specifying means220, a moving motion deciding means230, a receiving/passing motion deciding means240, and a time measuring means250.

The motion management means210obtains a task instruction signal sent from the robot managing unit3, and on the basis of the signal, controls the human specifying means220, the moving motion deciding means230, and the receiving/passing motion deciding means240.

The motion management means210outputs to the robot managing unit3, for example, direction data and position data of the robot R detected by the gyro-sensor SR1and the GPS receiver SR2, respectively.

The motion management means210also outputs to the robot managing unit3the motion reporting signal for reporting the task operation state of the robot R.

The human specifying means220specifies the human detected by the object sensing portion120, on the basis of the human information stored in the human data memory portion310and the tag ID number of the tag obtained by the object sensing portion120. Because the human data memory portion310stores the name of the human and the tag ID number of the tag unique to the human associated to each other, it is possible to determine whether or not the human near the robot R has something to do with the task operation by referring to those data and the task instruction signal.

The human specifying means220further specifies who is the moving object taken by the cameras C, C, on the basis of position data of the moving object extracted by the moving-object extraction portion102and position data of the sensing object sensed by the object sensing portion120.

The moving motion deciding means230is for determining the content of the autonomous movement of the robot R, and comprises a moving path deciding means231and a receiving/passing position deciding means232.

The moving path deciding means231determines a moving path of the robot R on the basis of the task instruction signal, the position data and the direction data of the robot R, the human data, and the map data.

The receiving/passing position deciding means232decides the position for the robot R to receive/pass the item from/to the human, on the basis of the position data on the moving object (human) detected the moving-object extraction portion120.

When the receiving/passing position deciding means232decides the receiving/passing position, the moving path deciding means231decides the moving path on which the robot R moves to the position. The receiving/passing position where the robot passes/receives the item to/from the human in a preferable manner is decided using the preset distance a1(seeFIG. 14).

The receiving/passing motion deciding means240is for determining the motion of the gripping portion71in the item-carrying operation, and comprises: a reception method deciding means241; a receiving/passing height deciding means242; means for determining to start receiving an item243; means for determining the completion of a receiving motion244; means for determining success/failure in gripping an item245; means for determining to start passing an item246; means for determining the completion of passing an item247; a carrying state setting means248, and a mastery level determining means249, The reception method deciding means241determines a receiving method on the basis of the instruction signal and the item data stored in the item data memory portion330.

The robot R of the present invention can select two receiving methods: use of one hand or both hands.

The one-hand and both-hand methods use one gripping portion71R (or71L) and both gripping portions71R,71L, respectively, to receive the item. The reception method deciding means241selects one of the two methods, on the basis of the size and weight in the item data. For example, the both-hand method is selected for receiving an item such as an A4sized document that is receivable with both hands, and the one-hand method for receiving a small-sized item not receivable with both hands.

The receiving/passing height deciding means242decides the height a3at which the gripping portion71is to grip an item (seeFIG. 17), on the basis of the body height of the human calculated by the moving-object extraction portion. The height a3is where the robot R passes/receives the item to/from the human in a preferable manner, and is selected in one of the three preset steps based on the calculated body height.

Via the autonomous movement controlling section150, the receiving/passing height deciding means242causes the gripping portion71to be held at the height of a3, with the direction from the human to the gripping portion71becoming a2, and the gripping portion71aligned with the center (central vertical line) of the human calculated by the

<Means for Determining to Start Receiving an Item>

The means for determining to start receiving an item243determines whether or not the human is holding an item at a receivable position for the robot R and the robot R can start receiving the item, and if yes, causes the gripping portion71to start the receiving motion.

The means for determining to start receiving an item243determines that the receiving motion can be started and drives the gripping portion71via the gripping portion controlling portion160to perform the finger closing motion, if the six-axis force sensor62detects the force Fx in the x axis as not less than a predetermined valued Fx1(first predetermined value) when the gripping portion71is not gripping an item, in particular, in a reception-wait state to be discussed later.

This is a control utilizing that the human passing an item to the robot R presses the item against the palm72.

<Means for Determining the Completion of Receiving Motion>

The means for determining the completion of a receiving motion244determines if the receiving motion has completed while the gripping portion71is receiving an item.

The means for determining the completion of a receiving motion244determines so if the six-axis force sensor62detects the force Fx in the x axis as not more than a predetermined valued Fx2(second predetermined value; Fx2≦Fx1).

This is a control using a decrease in the pressing force against the palm72caused by the human who has judged the robot R has received the item and released the hands therefrom.

The means for determining the completion of a receiving motion244determines the receiving motion has completed, if the opening degree of the gripping portion71is not more than a predetermined value, i.e., if the gripping angle deviation θ is not more than a (third) predetermined value θ1(e.g., θ=0) in the reception-wait state.

On determining that the receiving motion is completed, the means for determining the completion of a receiving motion244drives the gripping portion71via the gripping portion controlling portion to generate a torque in the finger closing direction for gripping the item.

<Means for Determining Success/Failure in Gripping an Item>

The means for determining success/failure in gripping an item245determines whether the gripping portion has gripped the item successfully or failingly.

In the present embodiment, when both hands are used to grip the item, the means for determining success/failure in gripping an item245moves the gripping portions71R,71L closer or apart to/from each other via the arm controlling portion152. Then, the means for determining success/failure in gripping an item245determines whether or not both of the gripping portions71R,71L are gripping the item, on the basis of the reaction force Fy from the item detected by the six-axis force sensor.

The means for determining success/failure in gripping an item245determines the gripping is successful if the reaction force Fy is not less than a predetermined value Fy1(fifth predetermined value).

<Means for Determining to Start Passing an Item>

The means for determining to start passing an item246determines whether the human is about to receive the item from the robot R when the robot is holding the item at a receivable position for the human, and if yes, then causes the gripping portion71to start receiving the item.

In the reception-wait state to be discussed later, the means for determining to start passing an item246determines the receiving motion can be started if the force Fx in the X axis detected by the six-axis force sensor is not less than a predetermined value Fx3, and drives the gripping portions71via the gripping portion controlling portion160to open the fingers.

This is a control utilizing that the human receiving the item from the robot R pulls the item.

The means for determining to start passing an item246determines the receiving motion can be started if the opening degree of the gripping portions71is not more than a predetermined value, that is, the gripping angle deviation θ is not more than a predetermined value θ2(e.g., θ=0) in the reception-wait state.

This is a control utilizing that the human receiving the item from the robot R pulls and removes the item from the gripping portions71, and thus the gripping portions71are closed with the gripping torque.

<Means for Determining the Completion of Passing an Item>

The means for determining the completion of passing an item247determines that the receiving motion has completed, if the force in the X axis detected by the six-axis force sensor is not more than a predetermined value Fx4(Fx4≦Fx3) in the item-receiving state to be described later.

This is a control utilizing a decrease in the external force Fx caused by the item to the gripping portions71when the human has completed receiving the item from the robot R.

<Means for Setting Carrying State>

The carrying state setting means248detects, sets, and updates the state of the gripping portion71.

The gripping portion71has the followings states.1. Free: The item-carriage request is not requested.2. Reception-wait: The robot is holding the gripping portion to the human and waiting for the human to pass the item to the robot.3. Receiving: The robot is receiving the item from the human, i.e., the human is passing the item to the robot.4. Receiving motion completed: The human has released the item from the hands and the item is (seems to be) on the side of the robot.5. Determining gripping success/failure: The robot determines if gripping the item has succeeded/failed.6. Reception failed: The robot has failed in receiving the item from the human.7. Gripping completed: The robot has succeeded in receiving the item from the human and is gripping the item.8. Passing-wait: The robot is holding the gripping portions toward the human and waiting for the human to receive the item.9. Passing: The robot is passing the item to the human, and the human is receiving the item from the robot.10. Passing completed: The robot has successfully passed the item to the human, i.e., the human has successfully received the item, which is now on the side of the human.11. Error: The item dropped during carriage, for example.
<Mastery Level Determining Means>

The mastery level determining means249determines the mastery level of the human in the receiving/passing motion.

The mastery level determining means249uses the time measuring means250, which is a clock provided in the main controlling portion200to measure the time required for the reception-wait state to change to the receiving state, or for the passing-wait state to the passing state. On the basis of the measured length of time, the mastery level determining means249determines the mastery level of the human. Here, the mastery level determining means249determines the mastery levels as high, middle, and low in the order from shorter to longer measuring time.

On the basis of the mastery level, the gripping portion controlling portion160sets the speed with which to close/open the fingers. That is, when the robot R conducts the receiving/passing motion to a human who is determined to have a low mastery level, the receiving/passing motion deciding means240causes the gripping portions71to slowly close/open the fingers to avoid giving the human a sense of discomfort.

When the robot R performs the receiving/passing motion to a human who is determined to have a high mastery level, the receiving/passing motion deciding means240causes the gripping portions71to fastly close/open the fingers to avoid giving the human a sense of botheration.

Based on the mastery level, the receiving/passing motion deciding means240also determines and then makes the speaker S output a speech base on speech data.

The robot R of the present invention will be discussed in terms of the item-carrying motion. Here, an exemplary case is taken in which the robot R has received an instruction signal pertaining to a task such as “receiving an item M from the human H1and then pass the item M to the human H2”. The item M is an A4sized document that the robot R can grip with both hands.

<Moving to the Receiving Position>

First, movement of the robot R toward the receiving position will be described.FIG. 13is a flowchart showing an item-carrying operation by a robot control system according to an embodiment of the invention, in which the robot is shown to move to a receiving position.

First, the robot R is waiting in the home position provided in the task task-performing area EA (Step1).

If the robot R receives the instruction signal sent from the robot managing unit3(Yes in Step2), then the robot R starts moving from the home position to a location where the human H1is usually present P1(Step3). On arriving at the location P1(Yes in Step4), the robot R stops moving and starts searching for the human H1(Step5).

On sensing the tag ID number of the human H1using the object sensing portion120(Yes in Step6), the robot R takes an image of the human H1using the cameras C, C (Yes in Step7), and then moves to the front of the human H1as shown inFIG. 14(Step8). InFIG. 14, the robot R is shown to have moved to the receiving position determined by the receiving/passing position deciding means232.

If the object sensing portion120could not sense the tag ID number of the human H1within a predetermined time period (Yes in Step9), the robot R generates and outputs to the robot managing unit3a motion reporting signal for reporting that the motion management means210could not perform the task, and then moves back to the home position (Step10).

Next will be discussed the receiving motion of the robot R.FIG. 15is a flowchart to show an item-carrying operation by the robot control system according to an embodiment of the invention, in which is shown an item-receiving motion.

After moving back to the receiving position, the robot R holds the gripping portions71R,71L with the fingers opened to the height determined by the receiving/passing height deciding means242as shown inFIGS. 16 and 17(Step21).

As shown inFIGS. 16 and 17, the robot R holds the gripping portions71(71R,71L) to the height a3decided by the receiving/passing height deciding means242such that the distance from the human H1to the gripping portions71R,71L is a2. Further, the robot R aligns the direction of holding the gripping portions71R,71L with the center (central vertical line) of the human H1calculated by the moving-object extraction portion102.

On completion of the holding motion of the gripping portions71R,71L, the carrying state setting means248sets the carrying state to the “reception-wait” state, and the robot R utters “Please pass me the item M” (Step S22)

When the robot R detects an external force Fx not less than Fx1with the six-axis force sensors62R,62L in the reception-wait state, the carrying state setting means248sets the carrying state as “receiving”, and the robot R starts closing the gripping portions71R,71L (Step24). InFIG. 18is illustrated a situation in which the robot R has started receiving the item M.

If the six-axis force sensor detects a force Fx not more than Fx2or if the gripping angle deviation θ is not more than θ1in the receiving state (Yes in Step25), then the carrying state setting means248sets the carrying state as “receiving motion completed”, and the gripping portions71R,71L grip the item M, as shown inFIG. 19.

Thereafter, the means for determining success/failure in gripping an item245determines the opening degrees of the gripping portions71R,71L (Step27).

If the opening degrees for both of the gripping portions71R,71L, i.e., the gripping angle deviation, is not less than a predetermined value θ3or a fourth predetermined value (condition D1), the means for determining success/failure in gripping an item245determines that the item M is thick and that both of the gripping portions71R,71L have gripped the item M, and the carrying state setting means248sets the carrying state as “gripping completed” (Step28).

If at least one of the gripping portions71R,71L has a gripping angle deviation θ less than a predetermined value θ3(condition D2), then the carrying state setting means248sets the carrying state as “determining gripping success/failure” (Step29), and the means for determining success/failure in gripping an item245determines the success/failure (Step30).

Specifically, the robot R moves closer or apart the gripping portions71R,71L to make the six-axis force sensors62R,62L detect the reactive force Fy applied from the item M. If the reaction force Fy is not less than the predetermined value Fy1(condition3), then the means for determining success/failure in gripping an item245determines the gripping is successful, the carrying state setting means248sets the carrying state as “receiving motion completed”, and the gripping portions71R,71L grip the item M.

If the reaction force Fy is less than the predetermined value Fy1(condition4), the means for determining success/failure in gripping an item245determines that the gripping is failed, and the carrying state setting means248sets the carrying state as “reception failed”.

Here, with reference toFIGS. 20A,20B,20C, determination on the gripping success/failure will be discussed.

As shown inFIG. 20A, when both of the gripping portions71R,71L are gripping the item M, moving the gripping portions closer will cause the reaction force Fy (not less than the predetermined value Fy1) due to the item M.

As shown inFIG. 20B, when only one of the griping portions71R,71L is gripping the item M (71R in the drawing), moving the gripping portions closer will only result in a small reaction force Fy due to the item M (Fy2≦Fy≦Fy1).

As shown inFIG. 20C, when none of the griping portions71R,71L is gripping the item M, moving the gripping portions closer will cause no reaction force Fy due to the item M (Fy=0).

Thus, the means for determining success/failure in gripping an item245can determine whether or not the robot R is gripping the item with both hands (gripping portions71R,71L) by determining the gripping is successful if the reaction force Fy is not less than the predetermined value Fy1.

Next will be described preparation by the robot R for re-receiving an item.FIG. 21is a flowchart to show an item-carrying operation by the robot control system according to an embodiment of the invention, in which a robot prepares for re-receiving the item from the human.

If the means for determining success/failure in gripping an item245determines that the gripping has failed (condition4in Step29), then the carrying state setting means248sets the state of the gripping portions as “reception failed” (Step41), and the means for determining success/failure in gripping an item254determines the state of the gripping portions71R,71L (Step42). In determining the gripping success/failure, if at least one of the six-axis force sensor62R,62L detects an external force Fy other than the predetermined value Fy2(condition5in Step42), then the carrying state setting means42sets the carrying state as “reception-wait”, and the robot R utters “Please, take the item M and pass it to me again” (Step43).

If one of the six-axis force sensors62R,62L on the side gripping the item M detects an external force Fx not less than a predetermined value Fx5(Yes in Step44), then the carrying state setting means248sets the carrying state as “passing the item”, and the gripping portions71R,71L are released (Step45). Thereafter, this step proceeds to Step22to reperform the receiving motion.

It is to be noted that if the gripping angle deviation θ of the gripping portions71R,71L is not more than a predetermined value θ4, e.g., θ=0 (condition D6), in the judgment of the gripping success/failure in Step42, then the robot R utters “Please pass me the item M again” and the gripping portions71R,71L are released (Step45). Thereafter, this step proceeds to Step22to reconduct the receiving motion.

<Moving and Carrying an Item>

Next will be discussed movement of the robot R for carrying the item.FIG. 22is a flowchart to show an item-carrying operation by the robot control system according to an embodiment of the invention, in which the robot moves and carries the item.

If gripping the item is completed in Step28, then the robot R moves the gripping portions71R,71L to a position (dead angle) out of the viewing area D21(seeFIG. 23) of the cameras C, C (Step61), in order to prevent the gripped item M from intervening the camera view.

The robot R then starts moving from the reception position to a location where the human H2is usually present P2(Step62). On arriving at the location P2(Yes in Step63), the robot R stops moving and starts searching for the human H2(Step64).

On detecting the tag ID number of the human H2using the object sensing portion120(Yes in Step65), the robot R obtains an image of the human H2using the cameras C, C (Yes in Step66), and moves to the front of the human H2(Step67).

If the object sensing portion120has failed in detecting the tag ID number of the human H2within a predetermined time period (Yes in Step68), then the robot R carries the item M to the item storage site B1provided in the task-performing area EA (seeFIG. 1).

<Motion of Passing an Item>

Next is described a motion by the robot R of passing an item to the human.FIG. 24is a flowchart to show an item-carrying operation by the robot control system according to an embodiment of the invention, in which the robot passes the item to the human.

As shown inFIGS. 25 and 26, after moving to the position for passing the item, the robot R holds the gripping portions71(71R,71L) gripping the item M to the reception height determined by the receiving/passing height deciding means242(Step81).

When the robot has completed in holding the gripping portions71R,71L thereto, the carrying state setting means248sets the carrying state as “passing-wait”, and then the robot R utters “Please, receive the item M” (Step82).

In the state the robot is waiting for the human to receive the item from the robot, if the six-axis force sensors62R,62L detect an external force Fx not less than the predetermined value Fx3, or if the gripping angle deviation θ is not more than the predetermined value θ2, for example θ=0 (Yes in Step83), then the carrying state setting means248sets the carrying state as “passing the item to the human” and the robot R starts opening the gripping portions71R,71L (Step84). InFIG. 27is illustrated a situation in which the human H2is about to receive the item M from the robot R.

In the state the robot is passing the item to the human, if the six-axis force sensors62R,62L detects a force Fx not more than the predetermined value Fx4(Fx4≦Fx3) (Yes in Step85), then the carrying state setting means248sets the carrying state as “passing the item is complete” (Step86).

On completion of passing the item M to the human, the robot R uses the motion management means210to generate and then output to the robot managing unit3a motion reporting signal for reporting the completion of the task implementation (Step87).

The robot R then moves from the receiving position to the home position (Step88).

If the robot R dropped the item M while moving to carry it, then the carrying state setting means248sets the carrying state as “error”, and the motion management means210generates and then outputs to the robot managing unit3a motion reporting signal for reporting the failure in carrying the item M.

In this embodiment, the receiving/passing motion deciding means240determines that the robot R has dropped the item M, if the gripping angle deviation θ is not more than a predetermined value θ5(e.g., θ=0).

If the force Fx detected by the six-axis force sensors changes to a large extent while the robot R is moving to carry the item (because the item M struck against an obstacle, for example), then the robot R temporarily stops the autonomous movement and waits for the Fx to return to a normal value.

Similarly, when the cameras C, C have detected an obstacle in their front (e.g., a human passing in front of the robot), the robot R temporarily stops the autonomous movement and waits for the obstacle to be removed.

<Moving to the Item Storage Site>

Next, movement of the robot R to the item storage site will be discussed.FIG. 28is a flowchart to show an item-carrying operation by the robot control system according to an embodiment of the invention, in which the robot moves to the item storage site.

If the robot R has failed in searching the human H2within a predetermined time period (Yes in Step68), then it moves from the location where the human H2is usually present P2to the item storage site B1(Step101).

The robot R then places the item M in the item storage site B1(Step102), generates a motion reporting signal for reporting the placement of the item M in the item storage site B1, and outputs the signal to the robot managing unit3and a terminal5for use by the human H2(Step103). Thereafter, the robot R moves from the item storage site B1to the home position (Step104).

As discussed heretofore, the robot control system according to an embodiment of the invention has the following effects.(1) When receiving an item from the human, the robot can determine that the human has completed receiving the item from the robot, by detecting a decrease in the pressing force of the item against the gripping portion which is caused when the human releases the hands from the item. Also the robot can prevent giving the human a sense that the item was forcefully taken away, by generating a gripping torque for gripping the item after completion of receiving the item.(2) The robot determines the mastery level of the human of receiving (passing) an item from (to) the robot by using the time period from the receiving (passing) wait state to starting receiving (passing) the item, so as to perform a receiving (passing) motion according to the mastery level. Thus, the robot can perform the receiving (passing) motion depending on the mastery levels, i.e., slowly and quickly for low and high mastery levels, respectively.(3) In receiving an item with both hands, the robot can check if they have successfully or failingly gripped the item even if the item is light and thin, by determining if the robot is gripping the item with both gripping portions. Further, even if the gripping has ended up in failure, it is possible to receive the item again (reperform the receiving motion).(4) By performing motions depending on the position and body height of the human, the robot can decrease the load for the human and perform receiving/passing motion in a more natural manner. That is, because the robot performs motions in an adapted manner to the human, the load is decreased for the human to behave according to the robot motions.(5) By utilizing a force in a horizontal direction out of the external forces from an item to control the receiving/passing motion, the robot can separately detect forces due to human motion and the self weight of the item, and thus prevent an erroneous motion due to the self weight of the item.

Although an embodiment of the present invention has been described above, the invention is not limited thereto but may be modified in construction as needed within the scope of the resent invention.

For example, the external force Fz in the Z axis detected by the six-axis force sensor may be used to determine if the robot has dropped the item in the carriage thereof, because when the item is dropped, Fz decreases and the sensor stops sensing the weight of the item.

The number and location, for example, of the joints of the robot may also be modified as needed.

Further, although the present embodiment employs a construction in which the receiving/passing motion deciding means, the human-position specifying means, the receiving/passing height deciding means, the body-height specifying means, the receiving/passing height deciding means, and the human specifying means are provided in the controlling sections installed in the robot, at least one of these means may be provided on the side of the robot managing unit.