1. A control device for a walking assist apparatus having a seat that receives a part of the weight of a sitting user from above, a pair of right and left thigh frames respectively connected to the seat through the intermediary of first joints, a pair of right and left crus frames respectively connected to the thigh frames through the intermediary of second joints, a pair of right and left foot-worn assemblies that are respectively connected to the crus frames through the intermediary of third joints, respectively attached to the feet of the right and left legs of the user, and come in contact with the ground when the legs of the user become standing legs, an actuator for the left for driving the second joint among the joints of the left leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the left side, and an actuator for the right for driving the second joint among the joints of the right leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the right side, the control device comprising:
a treading force measuring means for measuring a treading force of each leg of the user on the basis of a force detection value indicated by an output of a first force sensor provided in each of the foot-worn assemblies;
a desired lifting force setting means for setting a desired lifting force, which is a desired value of an upward lifting force to be applied to the user from the seat;
a distributing means for determining a desired share for the left leg link and a desired share for the right leg link out of the desired lifting force by distributing the desired lifting force to the leg links on the basis of the ratio between the treading force of the left leg and the treading force of the right leg of the user; and
an actuator controlling means for controlling the actuator for the left such that the lifting force actually imparted to the seat from the left leg link becomes the desired share for the left leg link and also controlling the actuator for the right such that the lifting force actually imparted to the seat from the right leg link becomes the desired share for the right leg link.
2. A control device for a walking assist apparatus having a seat that receives a part of the weight of a sitting user from above, a pair of right and left thigh frames respectively connected to the seat through the intermediary of first joints, a pair of right and left crus frames respectively connected to the thigh frames through the intermediary of second joints, a pair of right and left foot-worn assemblies that are respectively connected to the crus frames through the intermediary of third joints, respectively attached to the feet of the right and left legs of the user, and come in contact with the ground when the legs of the user become standing legs, an actuator for the left for driving the second joint among the joints of the left leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the left side, and an actuator for the right for driving the second joint among the joints of the right leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the right side, the control device comprising:
a treading force measuring means for measuring a treading force of each leg of the user on the basis of a force detection value indicated by an output of a first force sensor provided in each of the foot-worn assemblies;
a desired lifting force setting means for setting a desired lifting force, which is a desired value of an upward lifting force to be applied to the user from the seat;
a second force sensor provided between the bottom end of the crus frame and the third joint of each leg link or between the third joint and the foot-worn assembly of each leg link;
a force-to-be-controlled measuring means for measuring, as a force to be controlled, a force actually transmitted from the floor to the crus frame of each leg link on the basis of a force detection value indicated by an output of the second force sensor;
a total desired lifting force determining means for determining, as a total desired lifting force, the total sum of the desired lifting force and a supporting force for supporting on a floor the weight obtained by subtracting the total weight of the portions below the second force sensors in the walking assist apparatus from the weight of the entire walking assist apparatus or the total sum of the desired lifting force and a supporting force for supporting the weight of the entire walking assist apparatus on a floor;
a distributing means for determining a desired share for the left leg link and a desired share for the right leg link out of the total desired lifting force by distributing the total desired lifting force to the leg links on the basis of the ratio between a treading force of the left leg and a treading force of the right leg of the user; and
an actuator controlling means for controlling the actuator for the left on the basis of a force to be controlled and a desired share of the left leg link such that the difference between the force to be controlled and the desired share of the left leg link approximates zero and for controlling the actuator for the right on the basis of a force to be controlled and a desired share of the right leg link such that the difference between the force to be controlled and the desired share of the right leg link approximates zero.
3. The control device for a walking assist apparatus according to claim 1, wherein each of the foot-worn assemblies is equipped with an annular member for inserting a foot of the user, to which the foot-worn assembly is to be attached, from the toe end thereof, and connected to the third joint through the intermediary of the annular member.
4. The control device for a walking assist apparatus according to claim 2, wherein each of the foot-worn assemblies is equipped with an annular member for inserting a foot of the user, to which the foot-worn assembly is to be attached, from the toe end thereof, and connected to the third joint through the intermediary of the annular member.
5. The control device for a walking assist apparatus according to claim 1, wherein each of the first force sensors is composed of one or more force sensors provided in each foot-worn assembly such that, when a leg of the user becomes a standing leg, they are positioned between at least either the location of the metatarsophalangeal joint or the location of the heel of the foot on the bottom surface of the foot of the standing leg and a floor, and the treading force measuring means is a means that takes the total sum of the force detection values indicated by outputs of the force sensors constituting the first force sensor of each foot-worn assembly as a force detection value of the first force sensor and measures the treading force of a leg of the user that has the foot-worn assembly attached thereto on the basis of the force detection value of the total sum.
6. The control device for a walking assist apparatus according to claim 2, wherein each of the first force sensors is composed of one or more force sensors provided in each foot-worn assembly such that, when a leg of the user becomes a standing leg, they are positioned between at least either the location of the metatarsophalangeal joint or the location of the heel of the foot on the bottom surface of the foot of the standing leg and a floor, and the treading force measuring means is a means that takes the total sum of the force detection values indicated by outputs of the force sensors constituting the first force sensor of each foot-worn assembly as a force detection value of the first force sensor and measures a treading force of a leg of the user that has the foot-worn assembly attached thereto on the basis of the force detection value of the total sum.
7. The control device for a walking assist apparatus according to claim 3, wherein a foot supporting member for supporting a foot of the user is disposed inside an annular member of each of the foot-worn assemblies such that it does not come in contact with the annular member, and the foot supporting member is suspended in the annular member through the intermediary of the first force sensor.
8. The control device for a walking assist apparatus according to claim 4, wherein a foot supporting member for supporting a foot of the user is disposed inside an annular member of each of the foot-worn assemblies such that it does not come in contact with the annular member, and the foot supporting member is suspended in the annular member through the intermediary of the first force sensor.
9. The control device for a walking assist apparatus according to claim 1, wherein if a force detection value of the first force sensor is a first threshold value or less, the treading force measuring means sets a measurement value of a treading force of the foot to which the foot-worn assembly having the first force sensor has been attached to zero.
10. The control device for a walking assist apparatus according to claim 2, wherein if a force detection value of the first force sensor is a first threshold value or less, the treading force measuring means sets a measurement value of a treading force of the foot to which the foot-worn assembly having the first force sensor has been attached to zero.
11. The control device for a walking assist apparatus according to claim 1, wherein if a force detection value of the first force sensor is a predetermined second threshold value or more, then the treading force measuring means obtains a predetermined upper limit value, which is set beforehand, as a measurement value of a treading force of the foot to which the foot-worn assembly having the first force sensor has been attached.
12. The control device for a walking assist apparatus according to claim 2, wherein if a force detection value of the first force sensor is a predetermined second threshold value or more, then the treading force measuring means obtains a predetermined upper limit value, which is set beforehand, as a measurement value of a treading force of the foot to which the foot-worn assembly having the first force sensor has been attached.
13. The control device for a walking assist apparatus according to claim 1, comprising:
a displacement amount sensor that generates an output based on a displacement amount of the second joint;
a joint displacement amount measuring means for measuring a displacement amount of each second joint on the basis of an output of the displacement amount sensor; and
a desired share correcting means that determines a deviation of the interval between the third joint and the seat from a predetermined reference value on the basis of a measured displacement amount of the second joint of each leg link and then corrects the desired share of each leg link such that the deviation approximates zero.
14. The control device for a walking assist apparatus according to claim 2, comprising:
a displacement amount sensor that generates an output based on a displacement amount of the second joint;
a joint displacement amount measuring means for measuring a displacement amount of each second joint on the basis of an output of the displacement amount sensor; and
a desired share correcting means that determines a deviation of the interval between the third joint and the seat from a predetermined reference value on the basis of a measured displacement amount of the second joint of each leg link and then corrects the desired share of each leg link such that the deviation approximates zero.
15. The control device for a walking assist apparatus according to claim 13, wherein the desired share correcting means comprises:
a means for determining a required force for bringing the deviation close to zero by a feedback control law on the basis of the deviation associated with the left leg link;
a means for determining a correction amount of the desired share of the left leg link by multiplying the determined required force by the ratio of a treading force of the left leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and then correcting the desired share of the left leg link on the basis of the correction amount;
a means for determining a required force for bringing the deviation close to zero by the feedback control law on the basis of the deviation associated with the right leg link; and
a means for determining a correction amount of the desired share of the right leg link by multiplying the determined required force by the ratio of a treading force of the right leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and then correcting the desired share of the right leg link on the basis of the correction amount.
16. The control device for a walking assist apparatus according to claim 14, wherein the desired share correcting means comprises:
a means for determining a required force for bringing the deviation close to zero by a feedback control law on the basis of the deviation associated with the left leg link;
a means for determining a correction amount of the desired share of the left leg link by multiplying the determined required force by the ratio of a treading force of the left leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and then correcting the desired share of the left leg link on the basis of the correction amount;
a means for determining a required force for bringing the deviation close to zero by the feedback control law on the basis of the deviation associated with the right leg link; and
a means for determining a correction amount of the desired share of the right leg link by multiplying the determined required force by the ratio of a treading force of the right leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and then correcting the desired share of the right leg link on the basis of the correction amount.
17. The control device for a walking assist apparatus according to claim 2, comprising a selector switch for indicating whether to carry out the lifting force control,
wherein if the selector switch is in an operation state indicating that the lifting force control should be conducted, then the total desired lifting force determining means determines, as a total desired lifting force, the total sum of the desired lifting force and the supporting force for supporting on a floor the weight obtained by subtracting the total weight of the portions below the second force sensors in the walking assist apparatus from the weight of the entire walking assist apparatus or the total sum of the desired lifting force and a supporting force for supporting the weight of the entire walking assist apparatus on a floor, and if the selector switch is in an operation state indicating that the lifting force control should not be conducted, then the total sum of the forces-to-be-controlled of both leg links measured by the force-to-be-controlled measuring means is determined as the total desired lifting force.
18. The control device for a walking assist apparatus according to claim 2, comprising:
a displacement amount sensor that generates an output based on a displacement amount of the second joint;
a joint displacement amount measuring means for measuring a displacement amount of each second joint on the basis of an output of the displacement amount sensor;
a desired share correcting means that determines a deviation of the interval between the third joint and the seat from a predetermined reference value on the basis of a measured displacement amount of the second joint of each leg link and then corrects the desired share of each leg link such that the deviation approximates zero; and
a selector switch for indicating whether to carry out the lifting force control,
wherein if the selector switch is in an operation state indicating that the lifting force control should be conducted, then the total desired lifting force determining means determines, as a total desired lifting force, the total sum of the desired lifting force and the supporting force for supporting on a floor the weight obtained by subtracting the total weight of the portions under the second force sensors of the walking assist apparatus from the weight of the entire walking assist apparatus or the total sum of the desired lifting force and the supporting force for supporting the weight of the entire walking assist apparatus on a floor, and if the selector switch is in an operation state indicating that the lifting force control should not be conducted, then the total desired lifting force determining means determines, as the total desired lifting force, the value obtained by subtracting the correction amount of a desired share of each of both leg links supplied by the desired share correcting means from the total sum of the forces-to-be-controlled of both leg links measured by the force-to-be-controlled measuring means.
19. A control program for a walking assist apparatus that causes a computer for controlling a walking assist apparatus equipped with a seat that receives a part of the weight of a sitting user from above, a pair of right and left thigh frames respectively connected to the seat through the intermediary of first joints, a pair of right and left crus frames respectively connected to the thigh frames through the intermediary of second joints, a pair of right and left foot-worn assemblies that are respectively connected to the crus frames through the intermediary of third joints and respectively attached to the feet of the right and left legs of the user, and come in contact with the ground when the legs of the user become standing legs, an actuator for the left for driving the second joint among the joints of the left leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the left side, an actuator for the right for driving the second joint among the joints of the right leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the right side, and a first force sensor provided in each of the foot-worn assemblies for measuring a treading force of each leg of the user, to carry out:
processing for capturing an output of the first force sensor and measuring a treading force of each leg of the user on the basis of a force detection value indicated by the output;
processing for capturing a set value of a desired lifting force, which is a desired value of an upward lifting force to be applied to the user from the seat, and determining a desired share for the left leg link and a desired share for the right leg link out of the desired lifting force by distributing the set value of the desired lifting force on the basis of the ratio between a treading force of the left leg and a treading force of the right leg of the user; and
processing for generating a control output for controlling the actuator for the left such that the lifting force to be actually imparted to the seat from the left leg link becomes the determined desired share for the left leg link and also generating a control output for controlling the actuator for the right such that the lifting force to be actually imparted to the seat from the right leg link becomes the determined desired share for the right leg link.
20. A control program for a walking assist apparatus that causes a computer for controlling a walking assist apparatus equipped with a seat that receives a part of the weight of a sitting user from above, a pair of right and left thigh frames respectively connected to the seat through the intermediary of first joints, a pair of right and left crus frames respectively connected to the thigh frames through the intermediary of second joints, a pair of right and left foot-worn assemblies that are respectively connected to the crus frames through the intermediary of third joints and respectively attached to the feet of the right and left legs of the user, and come in contact with the ground when the legs of the user become standing legs, an actuator for the left for driving the second joint among the joints of the left leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the left side, an actuator for the right for driving the second joint among the joints of the right leg link composed of the first joint, the thigh frame, the second joint, the crus frame, the third joint, and the foot-worn assembly on the right side, a first force sensor provided in each of the foot-worn assemblies for measuring a treading force of each leg of the user, and a second force sensor provided between the bottom end of the crus frame and the third joint of each leg link or between the third joint and the foot-worn assembly of each leg link, to carry out:
processing for capturing an output of the first force sensor and measuring a treading force of each leg of the user on the basis of a force detection value indicated by the output;
processing for capturing an output of the second force sensor and measuring a force to be transmitted from the floor to the crus frame of each leg link as the force-to-be-controlled on the basis of a force detection value indicated by the output;
processing for capturing a set value of a desired lifting force, which is a desired value of an upward lifting force to be applied to the user from the seat, and determining, as the total desired lifting force, the total sum of the set value of the desired lifting force and the supporting force for supporting on a floor the weight obtained by subtracting the total weight of the portions under the second force sensors in the walking assist apparatus from the weight of the entire walking assist apparatus or the total sum of the desired lifting force and a supporting force for supporting the weight of the entire walking assist apparatus on a floor;
processing for distributing the determined total desired lifting force to leg links on the basis of a ratio between a treading force of the left leg and a treading force of the right leg of the user so as to determine a desired share of the left leg link and a desired share of the right leg link out of the total desired lifting force; and
processing for generating a control output for controlling the actuator for the left on the basis of a force-to-be-controlled and a desired share of the left leg link such that the difference between the force-to-be-controlled and the desired share of the left leg link approximates zero and also for generating a control output for controlling the actuator for the right on the basis of a force-to-be-controlled and a desired share of the right leg link such that the difference between the force-to-be-controlled and the desired share of the right leg link approximates zero.
21. The control program for a walking assist apparatus according to claim 19, wherein each of the first force sensor is composed of one or more force sensors provided in each of the foot-worn assemblies such that, when a leg of the user becomes a standing leg, the force sensor or the force sensors are positioned between at least one of the location of the metatarsophalangeal joint and the location of the heel of the foot on the bottom surface of the foot of the standing leg and a floor, and the processing for measuring the treading force is the processing for taking the total sum of the force detection values indicated by outputs of the force sensors constituting the first force sensor of each foot-worn assembly as the force detection value of the first force sensor and measuring the treading force of the leg of the user, to which the foot-worn assembly has been attached, on the basis of the force detection value.
22. The control program for a walking assist apparatus according to claim 20, wherein each of the first force sensor is composed of one or more force sensors provided in each of the foot-worn assemblies such that, when a leg of the user becomes a standing leg, the force sensor or the force sensors are positioned between at least one of the location of the metatarsophalangeal joint and the location of the heel of the foot on the bottom surface of the foot of the standing leg and a floor, and the processing for measuring the treading force is the processing for taking the total sum of the force detection values indicated by outputs of the force sensors constituting the first force sensor of each foot-worn assembly as the force detection value of the first force sensor and measuring the treading force of the leg of the user, to which the foot-worn assembly has been attached, on the basis of the force detection value.
23. The control program for a walking assist apparatus according to claim 19, wherein the processing for measuring treading forces is the processing for setting the measurement value of a treading force of the foot, to which the foot-worn assembly having the first force sensor has been attached, to zero when a force detection value of the first force sensor is a predetermined first threshold value or less.
24. The control program for a walking assist apparatus according to claim 20, wherein the processing for measuring treading forces is the processing for setting the measurement value of a treading force of the foot, to which the foot-worn assembly having the first force sensor has been attached, to zero when a force detection value of the first force sensor is a predetermined first threshold value or less.
25. The control program for a walking assist apparatus according to claim 19, wherein the processing for measuring treading forces is the processing for taking a predetermined upper limit value, which is set beforehand, as the measurement value of a treading force of the foot, to which the foot-worn assembly having the first force sensor has been attached, if a force detection value of the first force sensor is a predetermined second threshold value or more.
26. The control program for a walking assist apparatus according to claim 20, wherein the processing for measuring treading forces is the processing for taking a predetermined upper limit value, which is set beforehand, as the measurement value of a treading force of the foot, to which the foot-worn assembly having the first force sensor has been attached, if a force detection value of the first force sensor is a predetermined second threshold value or more.
27. The control program for a walking assist apparatus according to claim 19, wherein
the walking assist apparatus comprises a displacement amount sensor that generates an output based on a displacement amount of the second joint, and
the control program further causes the computer to perform processing for capturing an output of the displacement amount sensor, measuring the displacement amount of each second joint on the basis of the output, and determining the deviation of the interval between the third joint and the seat from a predetermined reference value on the basis of the measured displacement amount of the second joint of each leg link, and another processing for correcting the desired share of each leg link such that the determined deviation approximates zero.
28. The control program for a walking assist apparatus according to claim 20, wherein
the walking assist apparatus comprises a displacement amount sensor that generates an output based on a displacement amount of the second joint, and
the control program further causes the computer to perform processing for capturing an output of the displacement amount sensor, measuring the displacement amount of each second joint on the basis of the output, and determining the deviation of the interval between the third joint and the seat from a predetermined reference value on the basis of the measured displacement amount of the second joint of each leg link, and another processing for correcting the desired share of each leg link such that the determined deviation approximates zero.
29. The control program for a walking assist apparatus according to claim 27, wherein the processing for correcting a desired share comprises:
processing for determining a required force for bringing the deviation close to zero by a feedback control law on the basis of the deviation associated with the left leg link;
processing for determining a correction amount of the desired share of the left leg link by multiplying the determined required force by the ratio of a treading force of the left leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and correcting the desired share of the left leg link on the basis of the correction amount;
processing for determining a required force for bringing the deviation close to zero by the feedback control law on the basis of the deviation associated with the right leg link; and
processing for determining a correction amount of the desired share of the right leg link by multiplying the determined required force by the ratio of a treading force of the right leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and correcting the desired share of the right leg link on the basis of the correction amount.
30. The control program for a walking assist apparatus according to claim 28, wherein the processing for correcting a desired share comprises:
processing for determining a required force for bringing the deviation close to zero by a feedback control law on the basis of the deviation associated with the left leg link;
processing for determining a correction amount of the desired share of the left leg link by multiplying the determined required force by the ratio of a treading force of the left leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and correcting the desired share of the left leg link on the basis of the correction amount;
processing for determining a required force for bringing the deviation close to zero by the feedback control law on the basis of the deviation associated with the right leg link; and
processing for determining a correction amount of the desired share of the right leg link by multiplying the determined required force by the ratio of a treading force of the right leg relative to the total sum of a treading force of the left leg and a treading force of the right leg of the user, and correcting the desired share of the right leg link on the basis of the correction amount.
31. The control program for a walking assist apparatus according to claim 20, wherein
the walking assist apparatus comprises a selector switch for indicating whether to carry out lifting force control, and
the processing for determining a total desired lifting force is the processing in which, if the selector switch is in an operation state indicating that the lifting force control should be conducted, then the total sum of a set value of the desired lifting force and a supporting force for supporting on a floor the weight obtained by subtracting the total weight of the portions under the second force sensors of the walking assist apparatus from the weight of the entire walking assist apparatus or the total sum of the desired lifting force and a supporting force for supporting the weight of the entire walking assist apparatus on a floor is determined as the total desired lifting force, and if the selector switch is in an operation state indicating that the lifting force control should not be conducted, then the total sum of the measured forces-to-be-controlled of both leg links is determined as the total desired lifting force.
32. The control program for a walking assist apparatus according to claim 20, wherein
the walking assist apparatus comprises a displacement amount sensor for generating an output based on a displacement amount of the second joint and a selector switch for indicating whether or not to conduct lifting force control, and
the control program causes the computer to carry out the processing for capturing an output of the displacement amount sensor, measuring the displacement amount of each second joint on the basis of the output and determining the deviation of the interval between the third joint and the seat from a predetermined reference value on the basis of the measured displacement amount of the second joint of each leg link, and another processing for correcting the desired share of each leg link such that the determined deviation approximates zero, and
the processing for determining a total desired lifting force comprises the processing in which, if the selector switch is in an operation state indicating that the lifting force control should be conducted, then the total sum of a set value of the desired lifting force and a supporting force for supporting on a floor the weight obtained by subtracting the total weight of the portions below the second force sensors in the walking assist apparatus from the weight of the entire walking assist apparatus or the total sum of the desired lifting force and the supporting force for supporting the weight of the entire walking assist apparatus on a floor is determined as a total desired lifting force, or if the selector switch is in an operation state indicating that the lifting force control should not be conducted, then a value obtained by subtracting the correction amount of a desired share of each of both leg links supplied by the processing for correcting the desired share from the total sum of the measured forces-to-be-controlled of both leg links is determined as the total desired lifting force.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method for selecting cache replacement policies, comprising:
obtaining statistical data of multiple cache replacement policies that are running simultaneously; wherein among the multiple cache replacement policies only one active cache replacement policy decides whether to delete or reserve cache data; and
switching, according to an event of policy decision for cache replacement policies and the statistical data, from the active cache replacement policy to a cache replacement policy that complies with a policy decision requirement;
wherein the step of switching from the active cache replacement policy to the cache replacement policy that complies with the policy decision requirement comprises:
setting a flag of the cache replacement policy that complies with the policy decision requirement to active and setting a flag of the original active cache replacement policy to standby, wherein the \u201cactive\u201d flag indicates that the cache replacement policy whose flag is set as active is an active cache replacement policy and the \u201cstandby\u201d flag indicates that the cache replacement policy whose flag is set as standby is a standby cache replacement policy.
2. The method according to claim 1, wherein among the multiple cache replacement policies that are running simultaneously, only one cache replacement policy is an active cache replacement policy and the remaining cache replacement policies are standby cache replacement policies.
3. The method according claim 1, wherein the statistical data comprises at least one of a hit rate, a byte hit rate, and a latency time.
4. An apparatus implemented by hardware for selecting cache replacement policies, comprising:
an obtaining module, configured to obtain statistical data of multiple cache replacement policies that are running simultaneously; wherein among the multiple cache replacement policies only one active cache replacement policy decides whether to delete or reserve cache data; and
a switching module, configured to switch, according to an event of policy decision for cache replacement policies and the statistical data obtained by the obtaining module, from the active cache replacement policy to a cache replacement policy that complies with a policy decision requirement;
wherein the switching module is configured to set a flag of the cache replacement policy that complies with the policy decision requirement to active and set a flag of the original active cache replacement policy to standby, wherein the \u201cactive\u201d flag indicates that the cache replacement policy whose flag is set as active is an active cache replacement policy and the \u201cstandby\u201d flag indicates that the cache replacement policy whose flag is set as standby is a standby cache replacement policy.
5. The apparatus according to claim 4, wherein the apparatus further comprises multiple cache replacement policy modules configured to run different cache replacement policies.
6. The apparatus according to claim 5, wherein among the multiple cache replacement policy modules, only one cache replacement policy module runs an active cache replacement policy and the remaining cache replacement policy modules run standby cache replacement policies.
7. A system, comprising an apparatus for selecting cache replacement policies and a proxy server, wherein the apparatus is configured to obtain statistical data of multiple cache replacement policies that are running simultaneously from the proxy server, wherein among the multiple cache replacement policies only one active cache replacement policy decides whether to delete or reserve cache data; and switches, according to an event of policy decision for cache replacement policies and the obtained statistical data, from the active cache replacement policy to a cache replacement policy that complies with a policy decision requirement;
wherein the apparatus is further configured to set a flag of the cache replacement policy that complies with the policy decision requirement to active and set a flag of the original active cache replacement policy to standby, wherein the \u201cactive\u201d flag indicates that the cache replacement policy whose flag is set as active is an active cache replacement policy and the \u201cstandby\u201d flag indicates that the cache replacement policy whose flag is set as standby is a standby cache replacement policy.
8. The system according to claim 7, wherein the proxy server comprises multiple cache replacement policy modules, wherein only one cache replacement policy module runs an active cache replacement policy and the remaining cache replacement policy modules run standby cache replacement policies.