1. A fluid control system, comprising:
a pump;
a tank;
an actuator;
a valve assembly configured to control fluid communication between the actuator, the tank, and the pump; and
an energy recovery circuit including a pressure transformer and an energy storage device, the energy recovery circuit being fluidly coupled to the actuator in parallel with the valve assembly,
wherein the energy recovery circuit is configured to receive pressurized fluid flowing from the actuator and to store the pressurized fluid to the energy storage device.
2. The system of claim 1, wherein the valve assembly includes an independent metering valve arrangement.
3. The system of claim 1, wherein the actuator includes a head end chamber and a rod end chamber, and wherein the valve assembly includes a first valve configured to control fluid communication between the head end chamber and the tank, a second valve configured to control fluid communication between the head end chamber and the pump, a third valve configured to control fluid communication between the rod end chamber and the pump, and a fourth valve configured to control fluid communication between the rod end chamber and the tank.
4. The system of claim 1, wherein the actuator includes a head end chamber and a rod end chamber, and wherein the pressure transformer includes a head end port, a rod end port, and a high pressure port, the head end port being in fluid communication with the head end chamber, the rod end port being in fluid communication with the rod end chamber, and the high pressure port being in fluid communication with the energy storage device.
5. The system of claim 1, wherein the pressure transformer is a two quadrant hydraulic pressure transformer.
6. A fluid control system, comprising:
a pump;
a tank;
an actuator;
a valve assembly configured to control fluid communication between the actuator, the tank, and the pump; and
an energy recovery circuit including a pressure transformer and an energy storage device, the energy recovery circuit being fluidly coupled to the actuator in parallel with the valve assembly,
wherein the actuator includes a head end chamber and a rod end chamber,
wherein the pressure transformer includes a head end port, a rod end port, and a high pressure port, the head end port being in fluid communication with the head end chamber, the rod end port being in fluid communication with the rod end chamber, and the high pressure port being in fluid communication with the energy storage device, and
wherein the energy recovery circuit is configured to receive pressurized fluid flowing from at least one of the head end chamber and the rod end chamber and to store the pressurized fluid to the energy storage device.
7. The system of claim 6, wherein the energy recovery circuit is configured to supply pressurized fluid from the energy storage device to at least one of the head end chamber and the rod end chamber.
8. The system of claim 7, wherein the energy recovery circuit is configured to assist the valve assembly in operating the actuator.
9. The system of claim 7, wherein the energy recovery circuit is configured to operate the actuator independently of the valve assembly.
10. A fluid control system, comprising:
a pump;
a tank;
an actuator;
a valve assembly configured to control fluid communication between the actuator, the tank, and the pump; and
an energy recovery circuit including a pressure transformer, the energy recovery circuit being fluidly coupled to the actuator in parallel with the valve assembly,
wherein the pressure transformer is a four quadrant hydraulic pressure transformer.
11. A fluid control system, comprising:
a pump;
a tank;
an actuator;
an independent metering valve arrangement configured to control fluid communication between the actuator, the tank, and the pump; and
an energy recovery circuit being fluidly coupled to the actuator in parallel with the independent metering valve arrangement.
12. The system of claim 11, wherein the actuator includes a head end chamber and a rod end chamber, and wherein the independent metering valve arrangement includes a first valve configured to control fluid communication between the head end chamber and the tank, a second valve configured to control fluid communication between the head end chamber and the pump, a third valve configured to control fluid communication between the rod end chamber and the pump, and a fourth valve configured to control fluid communication between the rod end chamber and the tank.
13. The system of claim 11, wherein the energy recovery circuit includes a pressure transformer and an energy storage device.
14. The system of claim 13, wherein the actuator includes a head end chamber and a rod end chamber, and wherein the pressure transformer includes a head end port, a rod end port, and a high pressure port, the head end port being in fluid communication with the head end chamber, the rod end port being in fluid communication with the rod end chamber, and the high pressure port being in fluid communication with the high pressure chamber.
15. The system of claim 14, wherein the energy recovery circuit is configured to receive pressurized fluid flowing from at least one of the head end chamber and the rod end chamber and to store the pressurized fluid to the energy storage device.
16. The system of claim 15, wherein the energy recovery circuit is configured to supply pressurized fluid from the energy storage device to at least one of the head end chamber and the rod end chamber.
17. The system of claim 16, wherein the energy recovery circuit is configured to assist the independent metering valve arrangement in operating the actuator.
18. The system of claim 16, wherein the energy recovery circuit is configured to operate the actuator independently of the independent metering valve arrangement.
19. A method of operating a fluid control system including a pump, a tank, and an actuator having a head end chamber and a rod end chamber, the method comprising:
operating a valve assembly to control fluid communication between the actuator, the tank, and the pump;
receiving a first fluid flow from one of the head end chamber and the rod end chamber;
transforming the first fluid flow of a first pressure to a second fluid flow of a second pressure by supplying or discharging a third fluid flow of a third pressure; and
directing the second fluid flow to an energy storage device.
20. The method of claim 19, further including supplying pressurized fluid from the energy storage device to at least one of the head end chamber and the rod end chamber.
21. A fluid control system, comprising:
a pump;
a tank;
an actuator;
a valve assembly configured to control fluid communication between the actuator, the tank, and the pump; and
an energy recovery circuit including a pressure transformer, the energy recovery circuit being fluidly coupled to the actuator in parallel with the valve assembly,
wherein the valve assembly includes an independent metering valve arrangement.
22. A fluid control system, comprising:
a pump;
a tank;
an actuator;
a valve assembly configured to control fluid communication between the actuator, the tank, and the pump; and
an energy recovery circuit including a pressure transformer, the energy recovery circuit being fluidly coupled to the actuator in parallel with the valve assembly,
wherein the actuator includes a head end chamber and a rod end chamber, and
wherein the valve assembly includes a first valve configured to control fluid communication between the head end chamber and the tank, a second valve configured to control fluid communication between the head end chamber and the pump, a third valve configured to control fluid communication between the rod end chamber and the pump, and a fourth valve configured to control fluid communication between the rod end chamber and the tank.
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 logic checking to check an arbitration of an arbiter that is connected to a bus to which at least two master models and at least one slave circuit are connected, wherein each of the at least two master models is set to output a same signal to the bus as a corresponding one of at least two master circuits, wherein at least one slave model is set to output a same signal to the bus as the at least one slave circuit, and wherein a bus master model executes bus access in accordance with a bus protocol, the method comprising:
an outputting step of outputting requests from the at least two master models to the arbiter in accordance with the bus protocol by starting transitions of signals at a same cycle time, and outputting the signal from the at least one slave model in response to the signals outputted by the at least two master models; and
a checking step of checking the arbitration of the bus access by the arbiter in response to the signals output from the at least two master models and the at least one slave model.
2. The method according to claim 1, further comprising:
an activating step of activating the at least two master models at arbitrary times.
3. The method according to claim 1, wherein, in the outputting step, a plurality of bus master models output requests for bus access directly to the bus arbiter in respective states of concentrating and deconcentrating the requests.
4. The method according to claim 1, wherein the bus master model outputs a request for bus access without requiring any input data.
5. The method according to claim 1, wherein the bus master model can pause operation.
6. The method according to claim 1, wherein the bus master model corresponds to one of the at least two master circuits and outputs a request for bus access at a same frequency as a corresponding one of the at least two master circuits.
7. The method according to claim 1, wherein the bus master model corresponds to one of the at least two master circuits and outputs a request for bus access at a higher frequency than a corresponding one of the at least two master circuits.
8. The method according to claim 1, wherein, in the outputting step, a plurality of bus master models operate by independently setting operational conditions for each of the plurality of bus master models.
9. The method according to claim 1, wherein the bus master model and the at least two master circuits are used and connected to the bus.
10. The method according to claim 1, further comprising a connecting step of connecting the bus master model to the bus in place of one of the at least two master circuits.
11. The method according to claim 1, wherein, in the outputting step, the signals are output from the at least two master models and the at least one slave model at random times.
12. The method according to claim 1, wherein, in the outputting step, the at least one slave model responds to a request from one of the at least two master models after a passage of a random time period.
13. The method according to claim 1, wherein the at least two master models and the at least one slave model are connected directly to the bus.