Patent Publication Number: US-2021170572-A1

Title: Exoskeleton system, control device and control method

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an exoskeleton system, a control device and a control method, and more particularly, to an exoskeleton system, a control device and a control method capable of self-adjusting according to the frontal terrain. 
     2. Description of the Prior Art 
     Exoskeleton robots assist people having mobility problems or enhance users&#39; mobility, such as walking, stair climbing, slope climbing, and other applications. Generally speaking, a conventional control method of an exoskeleton robot is to input control commands (such as walking or going up and down along a slope or ramp) by the user with buttons or panels; however, the exoskeleton robot must be programmed in advance for its step distance, slope, and stair height in this method. Hence, the conventional exoskeleton robots are often obstructed due to the variance of the slope and stair height, which makes the user kick the uphill terrain and ascending stair, or makes the user lose balance because of the variance of the angel and stair height for the downhill terrain and descending stair. Under such circumstances, the conventional exoskeleton robots are inconvenient to operate, and may cause discomfort to the user due to improper movements, or even cause safety problems. 
     Therefore, it is necessary to improve the prior art. 
     SUMMARY OF THE INVENTION 
     It is therefore a primary objective of the present invention to provide an exoskeleton system, a control device and a control method, to improve over disadvantages of the prior art. 
     An embodiment of the present invention discloses a control device, applied to an exoskeleton system, comprising a sensing unit, configured to measure topographic data; and a processing unit, coupled to the sensing unit, configured to determine a frontal terrain of the exoskeleton system in a moving direction according to a measurement of the sensing unit to adjust an operation of a driving device of the exoskeleton system; wherein the sensing unit is configured to measure a distance and a direction of at least one measuring point corresponding to the sensing unit to measure the topographic data, wherein the at least one measuring point is located in front of the exoskeleton system in the moving direction. 
     An embodiment of the present invention further discloses an exoskeleton system, comprising at least one branch; a driving device, connected to the at least one branch, configured to drive the at least one branch according to a control signal; and a control device, comprising: a sensing unit, configured to measure a topographic data; and a processing unit, coupled to the sensing unit and the driving device, configured to determine a frontal terrain of the exoskeleton system in a moving direction according to a measurement of the sensing unit, to generate the control signal and to adjust an operation of a driving device; wherein the sensing unit is configured to measure a distance and a direction of at least one measuring point corresponding to the sensing unit to measure the topographic data, wherein the at least one measuring point is located in front of the exoskeleton system in the moving direction. 
     An embodiment of the present invention further discloses a control method, applied to an exoskeleton system, comprising measuring a topographic data; and determining a frontal terrain of the exoskeleton system in a moving direction according to the topographic data, to adjust an operation of a driving device of the exoskeleton system; wherein the step for measuring the topographic data comprises a distance and a direction of at least one measuring point corresponding to the exoskeleton system, wherein the at least one measuring point is located in front of the exoskeleton system in the moving direction. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a schematic diagram of an exoskeleton system according to an embodiment of the present invention. 
         FIG. 1B  is a functional block diagram of the exoskeleton system according to an embodiment of the present invention. 
         FIG. 2  is a schematic diagram of measuring a distance and a direction of a target point by a three-axis measuring method according to an embodiment of the present invention. 
         FIG. 3  is a schematic diagram of calculating a distance and a direction of a target point according to an embodiment of the present invention. 
         FIG. 4A to 4E  are schematic diagrams of determining the frontal terrain in the moving direction according to an embodiment of the present invention. 
         FIG. 5  is a schematic diagram of measuring a distance and a direction of a target point according to an embodiment of the present invention. 
         FIG. 6  is a schematic diagram of measuring a distance and a direction of a target point according to an embodiment of the present invention. 
         FIG. 7  is a schematic diagram of a control process according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A, 1B  are respectively a schematic diagram and a functional block diagram of an exoskeleton system  10  according to an embodiment of the present invention. The exoskeleton system  10 , used to assist human moving, comprises a trunk  100 , a branch  102 ,  104 ,  106 ,  108 , a driving device  110 , and a control device  112 . The branches  102 ,  104 ,  106  and  108  connected to the trunk  100 , and may be fixed to or worn on legs of a user; for example, the branch  102  corresponds to the left upper leg, the branch  104  corresponds to the left lower leg, the branch  106  corresponds to the right upper leg, and the branch  108  corresponds to the right lower leg. The driving device  110  comprises motors  114 ,  116 ,  118  and  120 , which are respectively connected to the branches  102 ,  104 ,  106  and  108 , and the driving device  110  drives operations of the branches  102 ,  104 ,  106  and  108  to assist the user to walk or run according to a control signal CTRL generated by the control device  112 . The control device  112  comprises a sensing unit  122  and a processing unit  124 . The sensing unit  122  measures frontal topographic data of the exoskeleton system in a moving direction thereof, and the processing unit  124  determines the frontal terrain, such as uphill, downhill, obstacles, etc. according to the measurement result of the sensing unit  122 , to generate a control signal CTRL to drive driving device  110 , for making exoskeleton system  10  to adjust the auxiliary force corresponding to the frontal terrain. 
     In brief, the control device  112  may measure the frontal topographic data or status in the moving direction of the exoskeleton system  10  worn by the user, and accordingly adjust the operation of the driving device  110 . Therefore, if there are obstacles, uphill, downhill, stairs and other terrain changes in the moving direction of the user, the embodiment of the present invention automatically adjusts the operation of the driving device  110  without control commands manually inputted by the user, such that the relative movements among the branches  102 ,  104 ,  106  and  108  fit the follow-up terrain changes, so as to assist the user more efficiently and enhance convenience. 
     Notably,  FIG. 1A  and  FIG. 1B  illustrate an embodiment of the present invention, and those skilled in the art may make modifications and alterations accordingly, and not limited herein. For example, the sensing unit  122  may measure the frontal terrain data in various ways. In an embodiment, the sensing unit  122  may measure a distance and direction of at least one target point corresponding to the sensing unit  122 , and the processing unit  124  may execute geometric operations to determine contour coordinates of terrain changes and accordingly determine the corresponding frontal terrain. For example, please refer to  FIG. 2 , which is a schematic diagram of measuring a distance and a direction of a target point R k  by a three-axis measurement method according to an embodiment of the present invention. As shown in  FIG. 2 , in a measurement, the sensing unit  122  measures a distance d k  between the target point R k  and the sensing unit  122 , and the relationship between the target point R k  and the sensing unit  122  may be mapped to a three-axis coordinate system, wherein the origin O is the sensing unit  122 , and X-axis, Y-axis, and Z-axis represent the roll, pitch, and yaw respectively. 
     In addition, the sensing unit  122  may be fixed on any position of the exoskeleton system  10  as long as the topographic data is correctly measured. The sensing unit  122  may comprise a plurality of sensing subunits; for example, one of the sensing subunits is located on the branch of the left lower leg, and another sensing subunit is located on the branch of the right lower leg. As the configuration or disposition of the sensing unit  122  changes, calculation of the distance and direction between the target point and the sensing unit  122  needs to be adjusted. For example, please refer to  FIG. 3 , which is a schematic diagram of the sensing unit  122  calculating a distance and a direction of a target point according to an embodiment of the present invention. In the embodiment, the sensing unit  122  comprises two sensing subunits, one of the sensing subunits is disposed on the branch  104 , and the other one is disposed on the branch  108 . When the user walks naturally, the left (right) leg is a fulcrum, the sensing subunits of the sensing unit  122  may measure continuously distances d 0  to d 0  and angles a0 to an of the branch of the lower leg. After the operation of the processing unit  124 , the coordinates R 0  to R n  corresponding to the obstacle contour based on the origin of the processing unit  124  are obtained. If the coordinate system is set with the fulcrum (i.e., the bottom of branch of the lower leg) as the origin, the coordinate x of k-th target point R k  is R k [X]=L*cos(a k )+dk*cos(a k +δ); the coordinate y is R k [Y]=L*sin(a k )+dk*sin(a k +δ), wherein δ is the angle between the sensing unit  122  and the branch of the lower leg, and L is the length of the branch of the lower leg. 
     After obtaining the statistics of R k [X], R k [Y] mentioned above, the processing unit  124  may determine whether there exists a special frontal terrain in the moving direction according to the contour coordinates. For example,  FIG. 4A  is a schematic diagram of the processing unit  124  determining the frontal terrain in the moving direction according to an embodiment of the present invention. In this example, the sensing unit  122  comprises two sensing subunits, the one is disposed on the branch  104 , and the other one is deposed on the branch  108 , wherein the frontal terrains comprise uphill. As shown in  FIG. 4A , when the user walks naturally and lifts his/her left leg, the sensing subunit of the sensing unit  122  located on the right lower leg measures a plurality of target points R 0  to R n . As the index k of the target point increases, both of a k  and d k  decrease. As can be known by the geometric calculation, the Y coordinate R k [Y] of the target point R k  decreases as the X coordinates R k [X] decreases. Therefore, the embodiment determines that the frontal terrain of the exoskeleton system  10  in the moving direction is an uphill terrain, and the processing unit  124  may accordingly generate a control signal CTRL to adjust the motor  116 , to adjust the location of the next touchdown point corresponding to the branch  104  of the left lower leg. 
     Furthermore, when the user walks naturally and lifts his/her left leg, the bottom of the branch  108  corresponding to the right lower leg is the fulcrum. If the processing unit  124  determines that the frontal terrain is an uphill terrain according to the measurement result of the sensing unit  122 , then comparing with the touchdown point of the flat terrain, the vertical distance of the next touchdown point of the branch  104  of the left lower leg is shorter. In this situation, the control device  112  may adjust the operation of the motor  116  via the control signal CTRL, to make the next touchdown point of the branch  104  of the left lower leg to fit the uphill terrain; that is, the next touchdown point is higher than the original (flat terrain) touchdown point to avoid improper auxiliary force and ensure that the user can walk smoothly. 
     Similar to  FIG. 4A , please continue to refer to  FIG. 4B to 4E , which are schematic diagrams of the processing unit  124  determining the frontal terrains in the moving direction according to an embodiment of the present invention. In  FIG. 4B , the sensing unit  122  measures a plurality of target points R 0  to R n , and the processing unit  124  determines that the Y coordinate R t [Y] of a target point R t  within the target points R i  to R 0  decreases as the X coordinates R t [X] increases. Therefore, the embodiment determines that the frontal terrain of the exoskeleton system  10  in the moving direction is a downhill terrain, and the control device  112  may adjust the motor  116  via the control signal CTRL, to make a next touchdown point of branch  104  of the left lower leg to fit the download terrain; that is, the next touchdown point is lower than the original (flat terrain) touchdown point to avoid improper auxiliary force and ensure that the user can walk smoothly. 
     In  FIG. 4C , the sensing unit  122  measures a plurality of target points R 0  to R n , and the processing unit  124  determines that the Y coordinate R t [Y] of a target point R t  within the target points R i  to R 0  is kept the same no matter how the X coordinate R t [X] changes. Therefore, the embodiment determines the frontal terrain of the exoskeleton system  10  in the moving direction is an flat terrain, and the control device  112  may adjust the motor  116  via the control signal CTRL, to make a next touchdown point of the branch  104  of the left lower leg to fit the flat terrain; that is, the next touchdown point is near to the original touchdown point to avoid improper auxiliary force and ensure that the user can walk smoothly. 
     In  FIG. 4D , the sensing unit  122  measures a plurality of target points R 0  to R n , and the processing unit  124  determines that the X coordinate R t [X] of a target point R t  within the target points R i  to R 0  is kept the same while the Y coordinate R t [Y] is different (for example, considering coordinates of a first target point R a  and a second target point R b  within the target points R i  to R 0 , if the X coordinate R a [X] (the first value) of the first target point R a  and the Y coordinate R a [Y] (the second value) are taken as basis, when the X coordinate R b [X] of the second target point R b  is not greater than the first value R a [X], but the Y coordinate R b [Y] is greater than the second value (R a [Y])), the embodiment determines the frontal terrain of the exoskeleton system  10  in the moving direction is a bump. Meanwhile, the processing unit  124  may determine the size of the bump according to other target points (such as R c , R d  . . . ) within the target points R i  to R 0 . 
     Next, the processing unit  124  further determines that the Y coordinate R s [Y] of a target point R s  within the target points R i  to R 0  is kept the same no matter how the X coordinate R s [X] changes, which corresponds to the flat terrain. Therefore, combining the determining results of the target points R t  and R s , the processing unit  124  may determine that the frontal terrain of the exoskeleton system  10  in the moving direction is an ascending stair, and the control device  112  may adjust the motor  116  via the control signal CTRL, to make a next touchdown point of branch  104  of the left lower leg to fit the ascending stair; that is, the next touchdown point is on the plate of the ascending stair to avoid improper auxiliary force and ensure that the user can walk smoothly. 
     In  FIG. 4E , the sensing unit  122  measures a plurality of target points R 0  to R n , and the processing unit  124  determines that the Y coordinate R t [Y] of a target point R t  within the target points R i  to R 0  is kept the same no matter how the X coordinate R t [X] changes, and the Y coordinate R s [Y] of a target point R s  within the target points R i  to R 0  is kept the same no matter how the X coordinate R s [X] changes. The processing unit  124  may determine that the frontal terrain of the exoskeleton system  10  in the moving direction is a flat terrain, and the processing unit  124  may further determine that the frontal terrain of the exoskeleton system  10  in the moving direction is a descending stair according to R t [Y]&gt;R s [Y]. Thus, the control device  112  may adjust the motor  116  via the control signal CTRL, to make a next touchdown point of the branch  104  of the left lower leg to fit the descending stair; that is, the next touchdown point is on the plate of the descending stair to avoid improper auxiliary force and ensure that the user can walk smoothly. 
     Therefore, via the determining methods shown in  FIG. 4A to 4E , the processing unit  124  may determine that the frontal terrain of the exoskeleton system  10  in the moving direction is an uphill, downhill, flat, bump, ascending stair, and descending stair terrain, and accordingly adjust the driving device  110 . For example, when the user walks naturally and lifts his/her left leg, the bottom of the branch  108  corresponding to the right lower leg is the fulcrum, the processing unit  124  determines the frontal terrain is an uphill, downhill, flat, bump, ascending stair, and descending stair, and adjusts the driving device  110  to make a next touchdown point of branch  104  of the left lower leg to fit the terrain. When the processing unit  124  determines that the frontal terrain is a bump, and if the bump does not hinder walking, then the processing unit  124  adjusts the driving device  110  to make the bottom of branch cross the bump; if the horizontal position of the bump is the same as the original step, then the processing unit  124  adjusts the driving device  110  to make the bottom of branch to be on the bump; or, if the vertical height of the bump is too large to cross, then the processing unit  124  adjusts the driving device  110  to make the exoskeleton system  10  to bypass the bump, shows a warning message to the user, or stops walking. In this way, the exoskeleton system  10  may adjust the auxiliary force corresponding to the frontal terrain by measuring the frontal terrain in the moving direction, and ensure that the user can walk smoothly without the user&#39;s indication. 
     Notably,  FIG. 3  and  FIG. 4A to 4E  illustrate the terrain determining method of the processing unit  124  in the condition that the sensing unit  122  comprises two sensing subunits, which are disposed on the branches of the left lower leg and the right lower leg respectively, the processing unit  124 . However, not limited herein, the sensing unit  122  may be disposed on any location according to different system requirements. For example, please refer to  FIG. 5 , which is a schematic diagram of the sensing unit  122  measuring a distance and a direction of a target point according to an embodiment of the present invention. In this example, because the sensing unit  122  is disposed on the user&#39;s waist, the geometric operation implemented by the processing unit  124  corresponding to the target point R k  should be adjusted as follows: the coordinate X is) R k [X]=L*cos(90°)+d k *cos(90°+δ), and the coordinate Y is R k [Y]=L*sin(90o)+d k *sin(90°+δ), wherein δ is the angel between the sensing unit  122  and the user&#39;s waist, and L is the height of the location on which the sensing unit  122  is disposed. The rest details of determining the terrain according to the coordinates of the target points may be referred to the above, which are not narrated herein for brevity. 
     In addition, as mentioned above, the sensing unit  122  may be implemented by a plurality of sensing subunits, and the sensing subunits may not limit to be disposed on the waist or legs. For example, please refer to  FIG. 6 , which is a schematic diagram of the sensing unit  122  comprising two sensing subunits disposed at locations corresponding to user&#39;s waist and leg in the exoskeleton system  10  according to an embodiment of the present invention. As shown in  FIG. 6 , because the two sensing subunits of the sensing unit  122  are disposed on the user&#39;s waist and leg respectively to measure the target points from different heights, the determining results of the processing unit  124  are more precisely to fit the practical terrain, to enhance efficiency. Notably, increasing the number of sensing subunits may increase the sensing range and make the sensing results more accurate. And the methods of determining the frontal terrain of the exoskeleton system  10  for each of the sensing subunits are similar to those of the single sensing unit, which are not narrated herein for brevity. 
     In addition, in an embodiment of the present invention, the frontal terrain may be further classified. For example, the uphill terrain may be further classified into extremely gentle slopes with a slope of 5°, gentle slopes with a slope of 5°-15°, gentle steep slopes with a slope of 15°-25°, steep slopes with a slope of 25°-35°, and not limited herein. The control device  112  may adjust the driving device  110  according to different terrains and the requirements by the user. Furthermore, in an embodiment, the exoskeleton system  10  may comprise an input device, which provides the user to adjust the corresponding relation between the terrains and the driving device  110  or to limit the moving direction to the exoskeleton system  10 . For example, if the exoskeleton system  10  encounters an uphill terrain with a slope more than 30°, then the exoskeleton system  10  will bypass the uphill terrain instead of climbing the uphill terrain, and not limited herein. 
     On the other hand, the trunk  100  and the branches  102 ,  104 ,  106  and  108  may be made of metal, plastic or composite materials, and not limited herein. In an embodiment, each branch may further comprise sub-branches, wherein each (sub-)branch may comprise any number of sub-driving devices and sub-control devices, to adjust a partial or whole of the branch for the more detailed local actions according to different frontal terrains. In addition, the driving device  110  is not limited to be implemented by motors, and may be a pneumatic or hydraulic device. In an embodiment, the control device  112  may control the driving device  110  directly via an interface or indirectly via an inter-process communication, and the control device  112  may transmit only the measurement results of the frontal terrain measured by the sensing unit  122  in the moving direction, which may be adjusted by a sub-processing unit of the driving device  110 . The control methods of the driving device  110  are well-known to those skilled in the art, which are not narrated herein for brevity. 
     In an embodiment, the sensing unit  122  may use optical, laser, radio, or ultrasonic methods to actively or passively sense terrain data. The sensing unit  122  may also be implemented by three-axis, six-axis, or nine-axis sensors, and may can transmit data to the processing unit  124  via a wire or wirelessly. In an embodiment, each unit may be implemented by an application-specific integrated circuit (ASIC). In an embodiment, the processing unit  124  may comprise a processor and a storage unit. The processor may be a processing unit, an application processor (AP) or a digital signal processor (DSP), wherein the processing unit may be a central processing unit (CPU), a graphics processing unit (GPU) or a tensor processing unit (TPU), and not limited thereto. The storage unit may be a memory, which may be a non-volatile memory, such as an electrically erasable programmable read-only memory (EEPROM) or a flash memory, and not limited thereto. 
     In an embodiment, the control device  112  may start to perform the control process for determining the frontal terrain in the moving direction only when detecting new step. For example, a step sensor may be configured to save the power consumption or reduce the interference to the exoskeleton system  10  when the user walks, to avoid discomfort to the user. The method of configuring the step sensor is known to those skilled in the art, which is not narrated herein for brevity. 
     In addition, the operation of the control device  112  may be summarized to a control process  70 , as shown in  FIG. 7 . The control process  70  comprises the following step: 
     Step  700 : Start. 
     Step  702 : The sensing unit  122  measures topographic data. 
     Step  704 : According to the topographic data measured by the sensing unit  122 , the processing unit  124  determines the frontal terrain of the exoskeleton system  10  in the moving direction, to adjust the operation of the driving device  110  of the exoskeleton system  10 . 
     Step  706 : End. 
     The detailed operation of the control process  70  may be referred to the foregoing description, which is not narrated herein for brevity. 
     Notably, the embodiments stated in the above are utilized for illustrating the concept of the present application. Those skilled in the art may make modifications and alterations accordingly, and not limited herein. Therefore, as long as the exoskeleton system may measure the frontal terrain in the moving direction and adjust the auxiliary force corresponding to the frontal terrain, the requirements of the present application are satisfied and within the scope of the present application. 
     In summary, to assist the user to walk or run, the exoskeleton system of the present invention measures the frontal terrain in the moving direction and adjusts the auxiliary force corresponding to the frontal terrain without the indication of the user. Therefore, the present invention can effectively improve the convenience of use and the smoothness of movement. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.