1. A method of diagnosing a problem in a multi-protocol label switching network, comprising:
hopping from a first network element to a second network element;
determining that a label switched path between the first network element and the second network element is not operational;
identifying that the hopping from the first network element to the second network element was strict;
finding an interior gateway protocol link between the first network element and the second network element;
remembering the interior gateway protocol link between the first network element and the second network element; and
diagnosing a cause of the label switched path between the first network element and the second network element not being operational.
2. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 1, further comprising altering a display of a topology map of the multi-protocol label switching network to indicate the cause of the label switched path between the first network element and the second network element not being operational.
3. A method of diagnosing a problem in a non-constrained shortest path first multi-protocol label switching network, comprising:
hopping from a first network element to a second network element;
determining that a label switched path between the first network element and the second network element is not operational;
identifying that the hopping from the first network element to the second network element was loose;
recognizing that the label switched path is a fast reroute label switched path; and
diagnosing a cause of the label switched path between the first network element and the second network element not being operational.
4. The method of diagnosing a problem in a non-constrained shortest path first multi-protocol label switching network, according to claim 3, further comprising altering a display of a topology map of the non-constrained shortest path first multi-protocol label switching network to indicate the cause of the label switched path between the first network element and the second network element not being operational.
5. A method of diagnosing a problem in a multi-protocol label switching network, comprising:
hopping from a first network element to a second network element;
determining that a label switched path between the first network element and the second network element is not operational;
evaluating whether there is an existing path between the first network element and the second network element; and
diagnosing a cause of the label switched path between the first network element and the second network element not being operational.
6. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 5, further comprising altering a display of a topology map of the multi-protocol label switching network to indicate the cause of the label switched path between the first network element and the second network element not being operational.
7. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 5, further comprising:
remembering an interior gateway protocol link between the first network element and the second network element; and
determining whether the interior gateway protocol link between the first network element and the second network element is operational.
8. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 7, further comprising evaluating whether a reservation protocol interface is configured in both directions between the first network element and the second network element.
9. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 7, further comprising evaluating whether an existing interior gateway protocol link between the first network element and the second network element is down.
10. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 9, further comprising evaluating whether an interior gateway protocol link exists between the first network element and the second network element.
11. The method of diagnosing a problem in a multi-protocol label switching network, according to claim 10, further comprising verifying that sufficient bandwidth exists on the interior gateway protocol link to satisfy bandwidth requirements of the label switched path.
12. A system for diagnosing a problem in a multi-protocol label switching network, comprising:
means for determining that a label switched path between a first network element and a second network element is not operational;
means for hopping from the first network element to the second network element;
means for identifying whether the hopping from the first network element to the second network element was loose or strict;
means for diagnosing a cause of the label switched path between the first network element and the second network element not being operational; and
means for altering a display of a topology map of the multi-protocol label switching network to indicate the cause of the label switched path between the first network element and the second network element not being operational.
13. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 12, wherein the multi-protocol label switching network is a non-constrained shortest path first multi-protocol label switching network.
14. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 12, wherein the multi-protocol label switching network is a constrained shortest path first multi-protocol label switching network.
15. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 12, further comprising means for finding and remembering an interior gateway protocol link between the first network element and the second network element.
16. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 12, further comprising means for determining whether an interior gateway protocol link between the first network element and the second network element is operational.
17. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 16, further comprising means for evaluating whether a reservation protocol interface is configured in both directions between the first network element and the second network element.
18. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 16, further comprising means for evaluating whether an existing interior gateway protocol link between the first network element and the second network element is down.
19. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 18, further comprising means for evaluating whether an interior gateway protocol link exists between the first network element and the second network element.
20. The system for diagnosing a problem in a multi-protocol label switching network, according to claim 19, further comprising means for verifying that sufficient bandwidth exists on the interior gateway protocol link to satisfy bandwidth requirements of the label switched path.
21. A diagnostic tool that diagnoses problems in a multi-protocol label switching network, comprising:
a reservation protocol label switched path manager that receives information regarding path changes between a plurality of elements in the multi-protocol label switching network;
a path monitor that monitors and evaluates the information regarding path changes between the plurality of elements in the multi-protocol label switching network, including diagnosing causes of label switched paths between the plurality of elements in the multi-protocol label switching network not being operational; and
a database that archives time-stamped historical information regarding path changes between the plurality of elements in the multi-protocol label switching network and causes of label switched paths between the plurality of elements in the multi-protocol label switching network not being operational.
22. A method of diagnosing a problem with a label distribution protocol tunnel, comprising:
performing an interior gateway protocol shortest path;
identifying a link in the interior gateway protocol shortest path;
evaluating whether an interface in the label distribution protocol is configured in both directions;
retrieving label distribution protocol bindings at a first end point and at a second end point of the label distribution protocol tunnel; and
altering a display of a topology map that includes the label distribution protocol tunnel.
23. The method of diagnosing a problem with a label distribution protocol tunnel, according to claim 22, further comprising performing a label distribution protocol ping to evaluate whether a label distribution protocol tunnel exists.
24. The method of diagnosing a problem with a label distribution protocol tunnel, according to claim 22, wherein retrieving label distribution protocol bindings at a first end point and at a second end point of the label distribution protocol tunnel includes retrieving a label of the first end point and retrieving a label of the second end point.
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 brake fluid pressure control apparatus for a vehicle comprising:
a fluid pressure passage extending from a fluid pressure source to a wheel brake;
a pressure regulating valve arranged on the fluid pressure passage, the pressure regulating valve allowing a flow of brake fluid from the fluid pressure source to the wheel brake while restricting a flow of brake fluid from the wheel brake to the fluid pressure source with a valve closing force according to an electric current applied to the valve;
a pump for feeding pressurized brake fluid to the fluid pressure passage between the pressure regulating valve and the wheel brake;
a motor for driving the pump; and
a controller which controls the electric current applied to the pressure regulating valve in accordance with a target fluid pressure for the wheel brake to control fluid pressure supplied to the wheel brake,
wherein the controller comprises:
means for converting the target fluid pressure into fluid volume and calculating a required flow rate based on this fluid volume;
means for calculating a required rotation speed of the motor based on the required flow rate and on the basis of an efficiency of the pump; and
means for increasing the electric current applied to the pressure regulating valve for a predetermined value when the required rotation speed exceeds an actual rotation speed of the motor obtained through detection or estimation.
2. The brake fluid pressure control apparatus according to claim 1, wherein the controller sets the predetermined value to a greater value as a difference between the actual rotation speed and the required rotation speed is greater.
3. A brake fluid pressure control apparatus for a vehicle comprising:
a fluid pressure passage extending from a fluid pressure source to a wheel brake;
a pressure regulating valve arranged on the fluid pressure passage, the pressure regulating valve allowing a flow of brake fluid from the fluid pressure source to the wheel brake while restricting a flow of brake fluid from the wheel brake to the fluid pressure source with a valve closing force according to an electric current applied to the valve;
a pump for feeding pressurized brake fluid to the fluid pressure passage between the pressure regulating valve and the wheel brake;
a motor for driving the pump; and
a controller which controls the electric current applied to the pressure regulating valve in accordance with a target fluid pressure for the wheel brake to control fluid pressure supplied to the wheel brake,
wherein the controller comprises:
a required flow rate calculation unit converting the target fluid pressure into fluid volume and calculating a required flow rate based on this fluid volume;
a required rotation speed calculation unit calculating a required rotation speed of the motor based on the required flow rate and on the basis of the efficiency of the pump; and
an electric current value determination unit increasing the electric current applied to the pressure regulating valve for a predetermined value when the required rotation speed exceeds an actual rotation speed of the motor obtained through detection or estimation.
4. The brake fluid pressure control apparatus according to claim 3, wherein the controller sets the predetermined value to a greater value as a difference between the actual rotation speed and the required rotation speed is greater.
5. The brake fluid pressure control apparatus according to claim 3, wherein the required flow rate calculation unit refers to a map showing relation between fluid pressure and fluid volume in a wheel cylinder provided on the wheel brake to obtain the fluid volume from the target fluid pressure; calculates a difference value between a current fluid volume and a former fluid volume; and divides the difference value by a sampling time from when the former fluid volume is obtained to when the current fluid volume is obtained to calculate the required flow rate.
6. The brake fluid pressure control apparatus according to claim 5, wherein the required rotation speed is obtained by the following formulae:
VMn
\ue89e
rpm
=
60
\xb7
Fn
\u03c0
\ue89e
\ue89e
r
2
\xb7
s
\xb7
\u03b6
where VMn is the required rotation speed of the motor, Fn is the required flow rate, r is a plunger radius of the pump, s is a plunger stroke of the pump, and \u03b6 is an efficiency of the pump.