Patent Application
20080154165
The present invention relates to a body weight support device and body weight support program for assisting a weight support by user's own legs.
Conventionally, it is known a walking assist device giving an assist propulsion for walking for a user. The walking assist device is used for assisting walking of a person who is difficult to walk by herself or himself such as a person whose a muscle force of her or his legs has lessened or whose legs has been injured. In addition, the walking assist device is also expected as such an exercise use and amusement use for aiming an improvement of a muscle force and a walking posture.
A walking aid device described in paragraphs 0034 to 0036 and FIGS. 15 and 16 of Japanese Patent Laid-Open Publication No. Hei. 5-329186 is attached to legs of a user and gives a constant propulsion to the user by rotating joints of a crotch, knees, and ankles with a joint drive device.
Although the walking aid device described in JP Hei. 5-329186 can alleviate a users fatigue accompanied with her or his movement by giving a propulsion in a walking direction, her or his weight is supported by her or his own legs and a load on the legs due to supporting the weight remains as it is. In addition, because the walking aid device firmly constrains user's whole legs with support members, he or she tends to feel an uncomfortable constraint feeling and an ache. Furthermore, such a configuration of constraining the whole legs with the support members needs to make the members fit each user well according to a body type and a way in walking.
Consequently, it is strongly requested a body weight support device that can alleviate a constraint of user's legs, is lightweight, and can reduce a load on the legs; and a body weight support program thereof.
A first aspect of the present invention is a body weight support device that comprises a body attachment part attached to a user's body, a floor contact part provided contactably on a floor, a leg link part for connecting the body attachment part to the floor contact part through a joint part, an actuator for driving the joint part, and a control unit for controlling a drive of the actuator, wherein the control unit drives the actuator so that the leg link part gives a body weight support force to the user through the body attachment part.
Here, the “body weight support force” means a force for supporting part of a user's weight. Thus it is enabled to reduce a load due to a user's weight on her or his legs. The “weight” is a weight where the user's weight and that of user's clothes and belongings are added and which the user must support by her or his own legs if he or she does not use the body weight support device of the present invention.
In addition, the joint part may be provide in at least one place of a connection portion of the body attachment part and the leg link part, that of the floor contact part and the leg link part, and an intermediate portion of the leg link part, and it is also considered that the joint part is provided, as one example, coaxially to a joint of a user's leg.
Thus it is enabled to provide a body weight support device that can alleviate a constraint of user's legs, is lightweight, and can reduce a load on the legs.
In addition, a second aspect of the present invention is the body weight support device of the first aspect that further comprises a floor contact detection mechanism for detecting a user's foot contact with a floor, and if the floor contact detection mechanism detects the floor contact, the control unit drives the actuator so that the leg link part gives the body weight support force to the user.
Here, the “user's foot contact with a floor” means a state of a floor reaction force being input in a user's foot. In other words, the “user's foot contact with a floor” includes not only a case of a user's foot directly contacting a floor but also a case of a shoe put on by her or him contacting the floor. Thus it is enabled to generate a body weight support force only when necessary.
In addition, a third aspect of the present invention is the body weight support device of the second aspect, and if the floor contact detection mechanism does not detect a floor contact, the control unit releases the drive of the actuator and makes the joint part rotation-free.
Thus in accordance with the third aspect of the present invention, there is no interruption of a motion of a user's foot not in contact with the floor.
In addition, a fourth aspect of the present invention is the body weight support device of the second aspect, and the actuator comprises a crotch joint part actuator for driving a crotch joint part provided in the leg link part, and if the floor contact detection mechanism does not detect a floor contact, the control unit drives the crotch joint part actuator so as to assist a upper thigh of the user to swing forward.
Thus in accordance with the fourth aspect of the present invention, it is enabled to assist a motion of a user's foot not in contact with the floor.
In addition, a fifth aspect of the present invention is the body weight support device of any one of the second to fourth aspects, and in the control unit a predetermined value of a target body weight support force is set, and if the floor contact detection mechanism detects a floor contact, the control unit drives the actuator so that the leg link part gives the target body weight support force to the user.
Thus in accordance with the fifth aspect of the present invention, it is enabled to give a predetermined body weight support force even if a user's posture changes.
In addition, a sixth aspect of the present invention is the body weight support device of any one of the second to fourth aspects, and in the control unit a target body weight support force of a predetermined ratio of a user's weight is set, and if the floor contact detection mechanism detects a floor contact, the control unit drives the actuator so as to give the target body weight support force of the predetermined ratio of the user's weight.
Thus in accordance with the sixth aspect of the present invention, it is enabled to control the actuator according to a user's weight.
In addition, a seventh aspect of the present invention is the body weight support device of either the fifth or sixth aspect that further comprises a load detection mechanism for detecting a user's load on the leg link part through the body attachment part, and in the control unit a lower limit value and upper limit value of the target body weight support force are set, and the control unit drives the actuator so that a body weight support force by the leg link part falls between the lower and upper limit values of the target body weight support force, based on the load detected by the load detection mechanism.
If a load detected by the load detection mechanism is smaller than the lower limit value of the target body weight support force, the control unit drives the actuator so as to enlarge the load. In addition, if the load detected by the load detection mechanism is larger than the upper limit value of the target body weight support force, the control unit drives the actuator so as to lessen the load.
Thus it is prevented for the body weight support force to become too large or too small, and it is enabled to control the drive of the actuator so as to give a correct range of a body weight support force.
In addition, an eighth aspect of the present invention is the body weight support device of any one of the first to sixth aspects that further comprises a load detection mechanism for detecting a user's load on the leg link part through the body attachment part, and the control unit drives the actuator, based on the load detected by the load detection mechanism.
A load detected by the load detection mechanism corresponds to a body weight support force by the leg link part. Thus in accordance with the eighth aspect of the present invention, feedback control using a current body weight support force is enabled.
In addition, a ninth aspect of the present invention is the body weight support device of any one of the first to eighth aspects, wherein the actuator comprises a knee joint part actuator for driving a knee joint part provided in the leg link part, and wherein the knee joint part and the knee joint part actuator are provided along the user's leg.
Thus in accordance with the ninth aspect of the present invention the body weight support device also tends to synchronize a human walking motion and a transmission efficiency of a body weight support force becomes better.
In addition, a tenth aspect of the present invention is the body weight support device of any one of the first to ninth aspects, wherein a portion where the body weight support force is given to the user through the leg link part and a portion where the user's load in the body attachment part is loaded are positioned within a substantially same vertical plane.
Here, the “vertical plane” means a plane vertical to a floor or parallel to a gravity direction. Thus in accordance with the tenth aspect of the present invention the body weight support device can prevent an unnecessary moment in a pitch direction (around a Y-axis) from being generated in a user.
In addition, an eleventh aspect of the present invention is the body weight support device of any one of the first to tenth aspects that further comprises a leg link part behavior detection mechanism for detecting a behavior of the leg link part, wherein the control unit drives the actuator, based on the behavior detected by the leg link part behavior detection mechanism.
As an example of the leg link part behavior detection mechanism can be cited a rotary encoder for detecting a rotation angle of the actuator. Thus in accordance with the eleventh aspect of the present invention the body weight support device can control a drive amount of the actuator according to a state of the leg link part, and a body weight support is enabled that does not give a bad influence on a user's posture.
In addition, a twelfth aspect of the present invention is the body weight support device of any one of the first to eleventh aspects, wherein the floor contact part is a foot attachment part attached to a user's foot.
Thus in accordance with the twelfth aspect of the present invention the body weight support device can make the floor contact part easily contact a floor.
In addition, a thirteenth aspect of the present invention is a body weight support program that functions a computer as an output instruction unit for driving an actuator so that a leg link part gives a body weight support force to a user through a body attachment part, in order to control a body weight support device that comprises the body attachment part attached to the user's body, a floor contact part provided contactably on a floor, a leg link part for connecting the body attachment part to the floor contact part through a joint part, and the actuator for driving the joint part.
In addition, a fourteenth aspect of the present invention is the body weight support program of the thirteenth aspect comprising the function of making the computer as a floor contact determination unit determine whether or not the user's foot has contacted the floor, based on a detection result of the floor contact detection mechanism, wherein the body weight support device further comprises a floor contact detection mechanism for detecting a user's foot contacting a floor, and wherein if the floor contact determination unit determines that the user's foot has contacted the floor, the output instruction unit drives the actuator so as to give a body weight support force to the user.
In addition, a fifteenth aspect of the present invention is the body weight support program of the fourteenth aspect, wherein if the floor contact determination unit determines that the user's foot has not contacted the floor, the output instruction unit releases a drive of the actuator and makes the joint part rotation-free.
In addition, a sixteenth aspect of the present invention is the body weight support program of the fourteenth aspect, wherein the body weight support device further comprises as the actuator a crotch joint part actuator for driving a crotch joint part provided in the leg link part, and wherein if the floor contact determination unit determines that the user's foot has not contacted the floor, the output instruction unit drives the crotch joint part actuator so as to assist a upper thigh of the user to swing forward.
In addition, a seventeenth aspect of the present invention is the body weight support program of any one of the fourteenth to sixteenth aspects further comprising the function of making the computer as a target assist force memory unit memorize a predetermined value of a target body weight support force, wherein if the floor contact determination unit determines that the user's foot has contacted the floor, the output instruction unit drives the actuator so that the leg link part gives the target body weight support force to the user.
In addition, an eighteenth aspect of the present invention is the body weight support program of any one of the fourteenth to sixteenth aspects further comprising the function of making the computer as a weight memory unit memorize a weight of the user and as a target assist force calculation unit calculate a target body weight support force of a predetermined ratio of the user's weight, based on the weight, wherein if the floor contact determination unit determines that the user's foot has contacted the floor, the output instruction unit drives the actuator so that the leg link part gives the target body weight support force to the user.
In addition, a nineteenth aspect of the present invention is the body weight support program of either the seventeenth or eighteenth aspect, wherein the body weight support device further comprises a load detection mechanism for detecting a load of the user on the leg link part through the body attachment part, wherein he target body weight support force has a lower limit value and upper limit value thereof, and wherein the output instruction unit drives the actuator so that a body weight support force by the leg link part falls between the lower and upper limit values of the target body weight support force, based on the load detected by the load detection mechanism.
In addition, a twentieth aspect of the present invention is the body weight support program of any one of the thirteenth to eighteenth aspects, wherein the body weight support device further comprises a load detection mechanism for detecting the users load on the leg link part through the body attachment part, and wherein the output instruction unit drives the actuator, based on the load detected by the load detection mechanism.
In addition, a twenty first aspect of the present invention is the body weight support program of any one of the thirteenth to twentieth aspects, wherein the body weight support device further comprises a leg link part behavior detection mechanism for detecting a behavior of the leg link part, and wherein the output instruction unit drives the actuator, based on the behavior detected by the leg link part behavior detection mechanism.
A principle of the present invention exists in a point that a floor contact side of a body weight support device generates a predetermined support force in a reverse direction to a gravity direction according to a user's walking, gives the support force to the user through a portion contacting the user, and thereby alleviates a weight support amount by the user's own legs.
The weight support force generated by the body weight support device of the present invention is given to, for example, such a crotch, upper thighs, a waist, armpits, and a jaw of a user.
Here will be described an embodiment of the present invention, referring to drawings as needed. A same symbol will be appended to a similar portion, and a duplicated description will be omitted. Meanwhile, with respect to an expression concerning a position, a direction, and the like, an X-axis is assumed to be in a user's front/back direction, a Y-axis in a user's left/right direction, and a Z-axis in a users up/down direction; and a description is made with making it a standard a state of a user's taking a standup posture. In addition, with respect to members provided to become a pair in left/right such as leg link parts, in a case of distinguishing them, an L (left) or an R (right) is appended to an end of a symbol; and in a case of not distinguishing them, a description is made without appending the L or the R.
Firstly, an embodiment of a body weight support device of the present invention will be described.
As shown in
In addition, an actuator of the body weight support device 1A comprises crotch joint part actuators 21a (left crotch joint part actuator 21aL, right crotch joint part actuator 21aR) and knee joint part actuators 23a (left knee joint part actuator 23aL, right knee joint part actuator 23aR).
As shown in
The waist belt part 11 is a girdle-form cloth member attached around the waist of the user P, and it is enabled to set a stop position by a buckle BU and to adjust a length in attachment thereof.
The upper thigh belt parts 12 (12L, 12R) are girdle-form cloth members attached around the upper thighs of the user P and upper ends thereof are fixed to the waist belt part 11.
The actuator attachment parts 13 (13L, 13R) are resin members for fitting the crotch joint part actuators 21a (21aL, 21aR) (see
The reinforcement members 14 (14L, 14R) are resin members for connecting the upper thigh belt parts 12 (12L, 12R) and the actuator attachment parts 13 (13L, 13R), and reinforces the actuator attachment parts 13 (13L, 13R) not to twist due to a torque counteraction of the crotch joint part actuators 21a (21aL, 21aR).
The loosing prevention belt part 15 is a cloth member for connecting the waist belt part 11 and the upper thigh belt parts 12 (12L, 12R) at the front side of the user P, and prevents the upper thigh belt parts 12 (12L, 12R) from loosening downward.
The loosing prevention belt parts 16 (16L, 16R) are cloth members for connecting the waist belt part 11 and the upper thigh belt parts 12 (12L, 12R) at the back side of the user P, and prevents the upper thigh belt parts 12 (12L, 12R) from loosening downward.
Meanwhile, the waist belt part 11 and the upper thigh belt parts 12 (12L, 12R) may also be made of resin. In addition, the actuator attachment parts 13 (13L, 13R) and the reinforcement members 14 (14L, 14R) may also be made of metal. Furthermore, the loosing prevention belt parts 15 and 16 (16L, 16R) may also be made of metal or resin.
In addition, in the loosing prevention belt parts 16 (16L, 16R) are provided load sensors 71a (71aL, 71aR).
The load sensors 71a (71aL, 71aR) detect a load of the user P on the leg link parts 20 (20L, 20 R) through the body attachment part 10 and are one example of the “load detection mechanism” in the “DISCLOSURE OF THE INVENTION.” Because when the body weight support device 1A supports part of a weight of the user P, the waist belt part 11 is supported by the leg link parts 20 (20L, 20 R) and the foot attachment parts 30 (30L, 30R), and on the other hand, the part of the weight of the user P is loaded on the upper thigh belt parts 12 (12L, 12R), a tension in the Z axis direction by the waist belt part 11 and the upper thigh belt parts 12 (12L, 12R) is generated at the loosing prevention belt parts 16 (16L, 16R). The load sensors 71a (71aL, 71aR) detect the tension, and thereby detect the weight of the user P loaded on the leg link parts 20.
As the load sensors 71a (71aL, 71aR), a sensor using a load cell, a strain gauge, a piezoelectric element, and the like is suitable. Meanwhile, although in the embodiment the load sensors 71a (71aL, 71aR) for a one-axis (Z axis) detection are used, they may also be designed to more accurately detect the weight of the user P loaded on the leg link parts 20, using a load sensor that can detect more than one axis. In addition, the load sensors 71a may also be attached to the loosening prevention belt part 15 at the front side; and fitting the load sensors 71a under the crotch of the user P, they may detect a pushing pressure by the user P.
The leg link parts 20 (20L, 20R) connect the body attachment part 10 and the foot attachment parts 30 (30L, 30R) through a plurality of joint parts, and are provided along outside of legs of the user P.
The leg link parts 20 (20L, 20R) comprise crotch joint parts 21 (left crotch joint part 21L, right crotch joint part 21R), upper thigh link parts 22 (left upper thigh link part 22L, right upper thigh link part 22R), knee joint parts 23 (left knee joint part 23L, right knee joint part 23R), lower thigh link parts 24 (left lower thigh link part 24L, right lower thigh link part 24R), and ankle joint parts 25 (left ankle joint part 25L, right ankle joint part 25R), respectively.
The crotch joint parts 21 (21L, 21R) are positioned outside crotch joints of the user P, respectively, and are nodes for rotatably connecting the waist belt part 11 and the upper thigh link parts 22 (22L, 22R) around the Y-axis.
The crotch joint parts 21 (21L, 21R) comprise the crotch joint part actuators 21a (left crotch joint part actuator 21aL, right crotch joint part actuator 21aR) and crotch joint part encoders 21b (left crotch joint part encoder 21bL, right crotch joint part encoder 21bR), respectively.
The crotch joint part actuators 21a (21aL, 21aR) comprise electric motors and reducers, respectively, bases of the actuators 21a (21aL, 21aR) are fixed to left/right parts of the actuator attachment part 13, and output shafts of the actuators 21a (21aL, 21aR) are fixed to upper ends of the upper thigh link parts 22 (22L, 22R). The output shafts of the crotch joint part actuators 21a (21aL, 21aR) rotate around the Y-axis, and thereby the upper thigh link parts 22 (22L, 22R) rotate around the Y-axis, respectively, making the crotch joint part actuators 21a (21aL, 21aR) axes for the waist belt part 11. Accordingly, the crotch joint part actuators 21a (21aL, 21aR) can generate torques between the waist belt part 11 and the upper thigh link parts 22 (22L, 22R). In a state of the crotch joint part actuators 21a (21aL, 21aR) not generating the torques, the crotch joint parts 21 (21L, 21R) become very small in rotation resistance thereof, result in becoming a rotation-free state, and thus do not cause a trouble in swinging forward a leg of the user P. Meanwhile, an attachment relationship of the crotch joint part actuators 21a (21aL, 21aR) is not limited to the above one.
The crotch joint part encoders (rotary encoders) 21b (21bL, 21bR) are one example of the “leg link part behavior detection mechanism” in the “DISCLOSURE OF THE INVENTION,” and as data concerning a behavior of the leg link parts 20 (20L, 20R), detect a rotation angle of the crotch joint part actuators 21a (21aL, 21aR). The rotation angle detected is output to a control unit 50.
The upper thigh link parts 22 (22L, 22R) are links extending along outside of upper thighs of the user P. Upper ends of the upper thigh link parts 22 (22L, 22R) are connected to the crotch joint parts 21 (21L, 21R), respectively. In addition, lower ends of the upper thigh link parts 22 (22L, 22R) are connected to the knee joint parts 23 (23L, 23R), respectively.
The knee joint parts 23 (23L, 23R) are positioned outside knee joints of the user P and are nodes for rotatably connecting the upper thigh link parts 22 (22L, 22R) and the lower thigh link parts 24 (24L, 24R) around the Y-axis. The knee joint parts 23 (23L, 23R) comprise the knee joint part actuators 23a (23aL, 23aR) and knee joint part encoders 23b (left knee joint part encoder 23bL, right knee joint part encoder 23bR).
The knee joint part actuators 23a (23aL, 23aR) comprise electric motors and reducers, respectively, bases of the actuators 23a (23aL, 23aR) are fixed to lower ends of the upper thigh link parts 22 (22L, 22R), and output shafts of the actuators 23a (23aL, 23aR) are fixed to upper ends of the lower thigh link parts 24 (24L, 24R). The output shafts of the knee joint part actuators 23a (23aL, 23aR) rotate around the Y-axis, and thereby the lower thigh link parts 24 (24L, 24R) rotate around the Y-axis, making the knee joint parts 23 (23aL, 23aR) axes for the upper thigh link parts 22 (22L, 22R). Accordingly, the knee joint part actuators 23a (23aL, 23aR) can generate torques between the upper thigh link parts 22 (22L, 22R) and the lower thigh link parts 24 (24L, 24R). In a state of the knee joint part actuators 23a (23aL, 23aR) not generating the torques, the knee joint parts 23 (23aL, 23aR) become very small in rotation resistance thereof, result in becoming a rotation-free state, and thus do not cause a trouble in swinging forward a leg of the user P. Meanwhile, the attachment relationship of the knee joint part actuators 23a (23aL, 23aR) is not limited to the above one.
The knee joint part encoders (rotary encoders) 23b (23bL, 23bR) are one example of the “knee link part behavior detection mechanism” in the “DISCLOSURE OF THE INVENTION,” and as data concerning the behavior of the leg link parts 20 (20L, 20R), detect a rotation angle of the knee joint part actuators 23a (23aL, 23aR). The rotation angle detected is output to the control unit 50.
The lower thigh link parts 24 (24L, 24R) are links extending along outside of lower thighs of the user P. Upper ends of the lower thigh link parts 24 (24L, 24R) are connected to the knee joint parts 23 (23L, 23R), respectively. In addition, lower ends of the lower thigh link parts 24 (24L, 24R) are connected to the ankle joint parts 25 (25L, 25R), respectively.
The ankle joint parts 25 (25L, 25R) are nodes for rotatably connecting the lower thigh link parts 24 (24L, 24R) and the foot attachment parts 30 (30L, 30 R) around the Y-axis. The ankle joint parts 25 (25L, 25R) move, following an operation of ankle joints of the user P, so as not to interrupt her or his walking motion.
As shown in
Meanwhile, the foot attachment parts 30 are one example of the “floor contact part” in the “DISCLOSURE OF THE INVENTION.”
The shoe 31 is a shoe contactably attached to a foot of the user P.
The reinforcement plate 32 is a resin member provided along outside of the foot of the user P, and is designed to be a structure of being able to transmit a floor reaction force received by the shoe 31 to the leg link part 20.
The support member 33 is a resin member for supporting the ankle joint part 25 in collaboration with the reinforcement plate 32. Meanwhile, the reinforcement plate 32 and the support member 33 may also be made of metal.
In the embodiment the leg link parts 20 and the foot attachment parts 30 have structures of being able to support part of the weight of the user P transmitted through the body attachment part 10.
In addition, at bottom of the shoe 31 is provided one of floor contact sensors 31a (left floor contact sensor 31aL, right floor contact sensor 31aR). The floor contact sensors 31a (31aL, 31aR) output an ON signal to the control unit 50 (see
The floor contact sensors 31a (31aL, 31aR) detect whether or not the foot attachment parts 30 has contacted the floor, and in the embodiment, are provided at foot bottoms of the foot attachment parts 30 (30L, 30R). The floor contact sensors 31a (31aL, 31aR) are one example of the “floor contact detection mechanism” in the “DISCLOSURE OF THE INVENTION.”
In addition, the “floor” is not limited to a floor of a building and may be a face such as a ground surface which the foot attachment parts 30 contact when the user P with the body weight support device 1A moves (walks).
As the floor contact sensors 31a (31aL, 31aR), a sensor using a conductive rubber switch, a piezoelectric element, and a strain gauge is suitable. Although in the embodiment the floor contact sensors 31a (31aL, 31aR) for a one-axis detection are used, they may also use a floor contact sensor that can detect more than one axis. In addition, although in the embodiment the floor contact sensors 31a (31aL, 31aR) are provided at center portions of bottoms of the shoes 31, respectively, they may also be provided at heel portions, respectively. In addition, a plurality of floor contact sensors 31a may be provided at one of the shoes 31.
Although in the embodiment the upper thigh link parts 22 (22L, 22R) and the lower thigh link parts 24 (24L, 24R) are assumed to be aluminum members, they may also be formed of another material such as carbon that is lightweight and has a sufficient strength. In other words, the body attachment part 10, the leg link parts 20 (20L, 20R), and the foot attachment parts 30 (30L, 30R) may have a strength that can give a body weight support force to the user P by either left or right ones of the leg link parts 20 and the foot attachment parts 30, and a material thereof is appropriately selectable.
The backpack 40 is something which the user P shoulders and comprises the control unit 50 (see
The input/output interface 60 connects an external computer and the like to the control unit 50. For example, personal data such as the weight of the user P is given to the control unit 50 from the external computer.
The battery supplies electric power to the load sensors 71a (71aL, 71aR), the crotch joint part actuators 21a (21aL, 21aR), the knee joint part actuators 23a (23aL, 23aR), the crotch joint part encoders 21b (21bL, 21bR), the knee joint part encoders 23b (23bL, 23bR), the floor contact sensors 31a (31aL, 31aR), and the control unit 50. The power supply by the battery is controlled by the control unit 50.
Meanwhile, the backpack 40 and the input/output interface 60 are not indispensable configuration requirements of the present invention. In other words, the attached mode of the control unit 50, the input/output interface 60, and the battery is not limited to one by the backpack 40, and such a mode of directly fitting them to the body attachment part 10 is also available.
Subsequently, the control unit 50 will be described.
As shown in
The weight memory unit 51 obtains the weight (weight data) of the user P and memorizes (temporary memory) it. The weight may be input to the control unit 50 directly by the user P or the weight which the control unit 50 recognizing the user P has memorized in advance may be read from the weight memory unit 51. In addition, the weight may also be designed to be input to the weight memory unit 51 through the input/output interface 60 from the external computer. In addition, the weight memory unit 51 may also be designed to memorize only a value of the weight of the user P as the weight.
The target assist force calculation unit 52 reads the weight data memorized in the weight memory unit 51, and calculates a target body weight support force based on the weight data.
The “target body weight support force” is a target value of a force (a Z-axis positive direction on a horizontal floor in a standup state) given to the user P by the body weight support device 1A, and a predetermined ratio (for example, 30% of the weight) of the weight of the user P is set. In the embodiment, together with a target body weight support force Fa, are calculated a minimum body weight support force Fa1 and a maximum body weight support force Fa2. Here, the minimum body weight support force Fa1 corresponds to the “lower limit value of the target body weight support force” and the maximum body weight support force Fa2 corresponds to the “upper limit value of the target body weight support force” in the “DISCLOSURE OF THE INVENTION.”
For example, in a case of setting a support force of 30% of the weight as the target body weight support force Fa, a value of 28% of the weight is calculated as the minimum body weight support force Fa1; a value of 32% of the weight is calculated as the maximum body weight support force Fa2. These assist forces Fa, Fa1, and Fa2 are appropriately set according to a body weight support force wanted to be given to the user P, a calculation capacity, a characteristic of each of the actuators 21a and 23a, a characteristic of each of the sensors 11a and 31a, and the like.
A ratio setting of the target body weight support force Fa, the minimum body weight support force Fa1, and the maximum body weight support force Fa2 is appropriately changeable, and for example, it is enabled to set an arbitrary value from the external computer through the input/output interface 60.
The initial torque value calculation unit 53 calculates initial torque values to be given to the left crotch joint part actuator 21aL, the right crotch joint part actuator 21aR, the left knee joint part actuator 23aL, and the right knee joint part actuator 23aR, based on the target body weight support force Fa.
The initial torque values are calculated for each of three cases: (1) both-feet floor contact; (2) left-foot floor contact (right foot not in contact with the floor); and (3) right-foot floor contact (left foot not in contact with the floor).
In other words, (1) in the case of the both-feet floor contact are calculated initial torque values given to the left crotch joint part actuator 21aL, the right crotch joint part actuator 21aR, the left knee joint part actuator 23aL, and the right knee joint part actuator 23aR; (2) in the case of the left-foot floor contact are calculated initial torque values given to the left crotch joint part actuator 21aL and the left knee joint part actuator 23aL, and then those given to the right crotch joint part actuator 21aR and the right knee joint part actuator 23aR are zero; and (3) in the case of the right-foot floor contact are calculated initial torque values given to the right crotch joint part actuator 21aR and the right knee joint part actuator 23aR, and then those given to the left crotch joint part actuator 21aL and the left knee joint part actuator 23aL are zero.
These initial torque values are ones for improving an initial response of the body weight support device 1A, and it is preferable to make the values that enable the device 1A to transit to a state of bringing out the target body weight support force Fa smoothly and early from an initial state. By generating torques in each actuator of the initial state according to its initial torque value, even if the user P abruptly leaves her or his weight to the body weight support device 1A, it surely prevents the user P from falling down or losing her or his balance and thus can stably establish her or his standup state. Here, as the initial state can be cited an activation of the body weight support device 1A and a change (both-feet floor contact to one-foot floor contact and vice versa) of a floor contact state thereof.
In addition, giving the initial torque values also contribute to a prevention of a trouble of the body weight support device 1A.
Meanwhile, because torque values to be output by the actuators 21a and 23a change according to the assist forces Fa, Fa1, and Fa2 and rotation angles of the actuators 21a and 23a, the initial torque value may be designed to be set with also using a current rotation angle of each of the actuators 21a and 23a.
The comparison unit 54 compares a body weight support force Fb (hereinafter simply referred to as “load Fb” if necessary) at present time, based on a detection load of the load sensors 71a (71aL, 71aR) with a calculation result of the target assist force calculation unit 52. The comparison unit 54 memorizes a relationship between an actual detection value by the load sensors 71a (71aL, 71aR) and a body weight support force by the leg link parts 20 in the actual detection value. Accordingly, the comparison unit 54 can obtain the body weight support force Fb actually acting, based on a detection result of the load sensors 71a (71aL, 71aR).
As a comparison result, there are three results: (11) Fb<Fa1; (12) Fa1≦Fb≦Fa2; and (13) Fb>Fa2. The comparison result is output to the output instruction unit 57.
Based on output from the left crotch joint part encoder 21bL, the right crotch joint part encoder 21bR, the left knee joint part encoder 23bL, and the right knee joint part encoder 23bR, the actuator state detection unit 55 detects a state of each of these joint parts. The detection result is output to the output instruction unit 57.
The floor contact foot determination unit 56 determines in which state of (1) both-feet floor contact, (2) left-foot floor contact, or (3) right-foot floor contact a floor contact foot is.
In other words, the floor contact foot determination unit 56 determines that: a case of there being output from both of the left floor contact sensor 31aL and the right floor contact sensor 31aR is (1) a state of both-feet floor contact; a case of there being output only from the left floor contact sensor 31aL is (2) a state of left-foot floor contact (right foot not in contact with the floor); and a case of there being output only from the right floor contact sensor 31aR is (1) a state of right-foot floor contact (left foot not in contact with the floor). The determination result is output to the output instruction unit 57.
The output instruction unit 57 decides and instructs output of each of the actuators 21aL, 21aR, 23aL, and 23aR, based on the calculation result of the initial torque value calculation unit 53, the comparison result of the comparison unit 54, the detection result of the actuator state detection unit 55, and the determination result of the floor contact foot determination unit 56.
The output instruction unit 57 expects a behavior of the leg link parts 20 (20L, 20R), based on the detection results of the actuator state detection unit 55 and these variation amounts, and decides the output of each of the actuators 21aL, 21aR, 23aL, and 23aR, based on the expectation result.
For example, in
Thus by moving the ratio of the body weight support force Fb to the left leg link part 20L, the right foot becomes in the air and can prepare (smooth transfer of a torque output fluctuation of the actuators) a state of having to support his weight only by a left system (the body attachment part 10, the left leg link part 20L, and the left foot attachment part 30L), and realize a more stable body weight support.
Subsequently, a torque generation direction of the crotch joint part actuators 21a (21aL, 21aR) and the knee joint part actuators 23a (23aL, 23aR) will be described.
In
As shown in
But as shown in
In other words, in order to bring out the sufficient body weight support force, the body weight support device 1A may respectively generate torques in such a direction that the crotch joint part actuators 21a (21aL, 21aR) make the angles θ 1 (θ 1L, θ 1R) larger, and in such a direction that the knee joint part actuators 23a (23aL, 23aR) make the angles θ 2 (θ 2L, θ 2R) smaller.
Meanwhile, each of the actuators 21a and 23a are controlled so that a movable range of each of the joint parts 21 and 23 does not exceed at least that of joint parts of an ordinary human being. Therefore, safety is further improved. In addition, the upper thigh link parts 22, the knee joint parts 23 (knee joint part actuators 23a), and the lower thigh link parts 24 are adjusted in length thereof so that the upper thigh link parts 22 and the lower thigh link parts 24 do not become in line (not fully elongated) and so that the knee joint parts 23 always become a bent state (avoidance of a singular point, see
[Relationship Between Generation Torque and Body Weight Support Force]
Subsequently, a relationship between a generation torque and a body weight support force will be described.
Firstly, referring to
If the right foot attachment part 30R contacts a floor and the right knee joint part actuator 23aR generates a torque in a direction of lessening the angle θ 2R, a rotation force is given to the right crotch joint part actuator 21aR in a tangential direction of a circle making the actuator 23aR a center. An anti-gravity direction (Z-axis direction) component of the rotation force is a body weight support force Fa1R by the right knee joint part actuator 23aR.
Subsequently, referring to
If the right foot attachment part 30R contacts the floor and the right crotch joint part actuator 21aR generates a torque in a direction of enlarging the angle θ 1R, a rotation force is given to the body attachment part 10 in a tangential direction of a circle making the actuator 21aR a center. The anti-gravity direction (Z-axis direction) component of the rotation force is a body weight support force Fa2R by the right crotch joint part actuator 21aR.
Meanwhile, although not shown, a body weight support force Fa1L by the left knee joint part actuator 23aL and a body weight support force Fa2L by the left crotch joint part actuator 21aL are generated appropriately, a target body weight support force (total assist force) Fa by the body weight support device 1A is expressed by following equations:
(1) both-feet floor contact
Fa=Fa1R+Fa2R+Fa1L+Fa2L;
(2) left-foot floor contact
Fa=Fa1L+Fa2L; and
(3) right-foot floor contact
Fa=Fa1R+Fa2R.
Subsequently, a load on the foot attachment parts 30 (30L, 30R) will be described.
[Operation Example of Body Weight Support Device]
Subsequently, an operation example of the body weight support device 1A will be described.
Firstly, in a state of the user P having put on the body weight support device 1A, the weight of the user P is input. The weight input is memorized in the weight memory unit 51 (step S1).
Subsequently, the target assist force calculation unit 52 calculates the target body weight support force Fa (Fa1, Fa2), based on the weight of the user P memorized in the weight memory unit 51 (step S2).
Subsequently, the initial torque value calculation unit 53 calculates an initial torque value, based on the target body weight support force Fa (step S3).
Subsequently, the floor contact foot determination unit 56 identifies a floor contact foot, based on the output of floor contact sensors 31a (step S4).
If it is determined that the floor contact foot is only the left foot, the output instruction unit 57 drives the left crotch joint part actuator 21aL and the left knee joint part actuator 23aL so as to generate a torque depending on the initial torque value (step S5a).
If it is determined that the floor contact foot is both feet, the output instruction unit 57 drives the left crotch joint part actuator 21aL, the right crotch joint part actuator 21aR, the left knee joint part actuator 23aL, and the right knee joint part actuator 23aR so as to generate a torque depending on the initial torque value (step S5b).
If it is determined that the floor contact foot is only the right foot, the output instruction unit 57 drives the right crotch joint part actuator 21aR and the right knee joint part actuator 23aR so as to generate a torque depending on the initial torque value (step S5c).
Subsequently, the load sensors 71a detect the load Fb (step S6), and the comparison unit 54 compares the detected load Fb with the calculated target body weight support force Fa (Fa1, Fa2) (step S7). Meanwhile, a detection value itself by the load sensors 71a may be simply compared to a threshold value of the detection value converted based on the calculated target body weight support force Fa.
If the load Fb is less than Fa1, the output instruction unit 57 increases a current amount to the actuators of a floor contact foot by a predetermined amount, and thus increases a generation torque by a predetermined amount (step 8a).
If the load Fb is not less than Fa1 and not more than Fa2, the output instruction unit 57 keeps the torque of the actuators of the floor contact foot (step 8b).
If the load Fb exceeds Fa2, the output instruction unit 57 decreases the current amount of the floor contact foot by a predetermined amount, and thus decreases a generation torque by a predetermined amount (step 8c).
Meanwhile, the predetermined amount for the increase/decrease of the current is appropriately set according to a calculation capacity of the control unit 50, a characteristic of each of the actuators 21a and 23a, and that of each of the sensors 71a and 31a.
Subsequently, if an OFF signal is input to the control unit 50 (Yes in step S9), the body weight support device 1A ends the processing. If the OFF signal is not input to the control unit 50 (No in the step S9), the floor contact foot determination unit 56 determines whether or not there exists a change of the floor contact foot (step S10).
If it is determined that there exists the change of the floor contact foot (both-feet floor contact to one-foot floor contact and vice versa) (Yes in the step S10), transit to the step S4. In addition, if it is determined that there does not exist the change of the floor contact foot (No in the step S10), transit to the step S6.
Subsequently, a state transition of the body weight support device 1A accompanied with the user P walking will be described, particularly taking notice of a state transition of the right leg part 20R.
Meanwhile, a walking mode is different in every user P and a knee angle in walking is also different in her or him. One example thereof is shown in
When the right leg of the user P is positioned at a most rear position (
If the user P swings forward (in the X-axis positive direction) her or his right leg, the right leg (right foot attachment part 30) is separated from the floor. Here, the generation torque of the right crotch joint part actuator 21aR and the right knee joint part actuator 23aR becomes “zero.” After the separation of the right leg, because the angle θ 1R gradually becomes smaller and the right foot attachment part 30R follows the knee joint part 23R with delaying for it, the angle θ 2R becomes larger for some time, and in a state of the angle θ 2R having become maximum (θ 2R=θ 2Rmax), the part 23R continues on being swung forward (
If the user P continues on swinging forward the right leg from the state 2, the angle θ 1R becomes minimum (θ 1R=θ 1Rmin) (
Meanwhile, it is also available to design in a leg being in the air so that each of the crotch joint part actuators 21a generates a torque in a counterclockwise direction in
In accordance with the body weight support device 1A following effects can be obtained.
(1) Because the body weight support device 1A supports part of the weight of the user P, it can reduce a load on her or his legs accompanying her or his weight support.
(2) Because the body weight support device 1A detects a load on herself or himself and supports a definite ratio of her or his weight, based on the load, it can perform a support corresponding to her or his posture change and the like.
(3) Because the body weight support device 1A gives a body weight support force only to a floor contact foot, it can give a suitable body weight support force accompanied with the change of a walking posture and dose not interrupt the operation of a leg not in contact with the floor.
(4) Because different from a stick (crutches, a four-point support stick, and the like) the body weight support device 1A does not need an operation by the hands of the user P, she or he can use the hands even during a walking assist. In addition, there is no possibility of her or his arms and upper body becoming tired, accompanied with a long time use thereof;
(5) Because the body weight support device 1A has a compact configuration along with the legs of the user P, it does not become an obstacle even in moving a narrow passage, staircases, and the like. In addition, because a configuration of each of the actuators 21a and 23a and the link parts 22 and 24 is analogous to a mechanism of a human lower limb, and these are arranged along the limbs (legs) of the user P, the configuration tends more to synchronize a human walking operation and is better in a transmission efficiency of the body weight support force than a configuration using a directly moved actuator and an assist device of a configuration of being separated from the lower limbs of the user P.
(6) Because the body weight support device 1A does not need a wheel, it can be used without depending on a floor condition.
(7) The body weight support device 1A has less constraint regions in the user P, it is suitable for a long time use. In other words, different from a conventional walking aid device, because the device 1A related to the embodiment of the present invention does not need the constraint of such knees and upper thighs and can almost do without the constraint of the legs of the user P, she or he does not feel an uncomfortable constraint and ache. In addition, the body weight support device 1A does with less constraint regions, it can be lighter weight, various users can use the body weight support device 1A of one type, and thus the device 1A results in being very high in versatility.
(8) In addition, the body weight support device 1A also has a feature that a portion (attachment portion of the crotch joint part actuators 21a) where the body weight support force is given to the user P from the device 1A and a portion (upper thigh portion and groin portion of the body attachment part 10) where she or he leaves her or his weight are positioned within a substantially same vertical plane (Y-Z plane in
[Variation Example]
Subsequently, concerning variation examples of the body attachment part 10 will be mainly described a difference from the body weight support device 1A.
A body attachment part 110 of a body weight support device 1B shown in
The body weight support device 1B is realized to be lightweight by making the belt of the body attachment part 10 simpler than the body weight support device 1A shown in
A body attachment part 210 of the body weight support device 1C shown in
The body weight support device 1C is an example of heightening a support function in the upper thighs of the user P more than the body weight support device 1B and instead alleviating a stress in her or his groin portion.
A body attachment part 310 of the body weight support device 1D shown in
The body weight support device 1D is an example suitable for the user P that is difficult to constrain her or his upper thighs and groin portion due to a disease, an injury, and the like.
Other than these is also available such a device configuration where a body weight support force by a body weight support device is given to a jaw portion of the user P.
Subsequently, concerning a variation example of the control unit 50 will be mainly described a difference from the body weight support device 1A.
A control unit 450 of a body weight support device 1E shown in
The target assist force memory unit 451 memorizes the target body weight support force Fa (for example, 10 kg) of a predetermined value set in advance. In addition, the target assist force memory unit 451 memorizes the minimum body weight support force Fa1 (for example, 9 kg) and the maximum body weight support force Fa2 (for example, 11 kg) corresponding to the target body weight support force Fa. In an operation flow of such the body weight support device 1E is calculated an initial torque value using these values, and a torque of an actuator is controlled.
Although the embodiment of the present invention is described, referring to the drawings, the invention is not limited thereto and the embodiment is appropriately changeable in design without departing the spirit and scope of the invention.
(1) Although each of the above mentioned body weight support devices is designed to integrate a joint part and an actuator, they may be designed to be separate bodies and to transmit a drive force of the actuator to the joint part through a drive force transmission mechanism comprising a link mechanism, a belt, and the like.
(2) The body weight support device may also be designed to omit a crotch joint part actuator and to drive the joint part only by a knee joint part actuator. In this case are realized the lightweight of the body weight support device and the simplification of the control.
(3) Although the body weight support device is designed to arrange each actuator and each link part along outside of a user's limb, all actuators and link parts or at least one of them may also be arranged inside the user's lower limb.
(4) The body weight support device may also be such a configuration that each foot attachment part is omitted and a lower end of a lower thigh link part contacts a floor. In this case, while synchronizing the body weight support device with a walking operation of a user by providing a lower limb attachment part, which is connected to a leg link part instead of her or his foot constraint by the foot attachment part and is attached to any of an ankle, a lower thigh, a knee, and a upper thigh, body weight support control is enabled by detecting a floor contact foot with a floor contact sensor provided at any of her or his foot bottom and a lower end of the lower thigh link part.
(5) Although in the control flow of
(6) Although each of the body weight support devices is provided in both lower limbs of a user, it may also be a configuration of being provided in either one of the right or left limb. For example, in a case that a function of only one foot of the user is lowered, a body weight support force can be given by providing the body weight support device only in the lower limb whose function is lowered.
In accordance with the present invention can be realized a body weight support device that can alleviate the constraint of legs of a user, is lightweight, can reduce a load on the legs, and fits each user well according to a body type and a way in walking, and a body weight support program therefor.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-382093 | Dec 2004 | JP | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/JP2005/015034 | 8/11/2005 | WO | 00 | 9/24/2007 |
