1. A communication interface device in a first computer from among a plurality of computers in a parallel computer architecture that executes, upon receiving a packet from a transmitting computer, an operation associated with received packet, the communication interface device comprising:
a chain atomic command storage unit that stores therein a plurality of atomic commands to transmit a communication packet, each of the atomic commands being chained using an address that indicates a next chained atomic command;
a chain atomic command designating unit that conducts a memory operation in a memory of the first computer on the basis of the packet received from the transmission computer and designates, from among the atomic commands stored in the chain atomic command storage unit, an atomic command by a pointer included in the packet received from the transmission computer; and
a chain atomic command executing unit that executes the designated atomic command, designates an atomic command chained with the designated atomic command among the atomic commands stored in the chain atomic command storage unit, and executes the chained atomic command.
2. The communication interface device according to claim 1, wherein the chain atomic command designating unit conducts a memory operation in response to a packet transmitted by the first computer and designates, from among the atomic commands stored in the chain atomic command storage unit, an atomic command by a pointer included in the packet transmitted by the first computer.
3. The communication interface device according to claim 1, further comprising an interrupt issuance condition determining unit that determines, every time a packet is received owing to the atomic command executed in association with a synchronous process by the chain atomic command executing unit of each of a plurality of transmitting computers, whether a result of the memory operation conducted on the atomic command meets a predetermined condition, wherein
when the interrupt issuance condition determining unit determines that a result of the memory operation meets the predetermined condition, the chain atomic command designating unit designates an atomic command by a pointer included in the received packet.
4. The communication interface device according to claim 1, further comprising a chain atomic command execution completion determining unit that determines whether all the chained atomic commands stored in the chain atomic command storage unit are executed by the chain atomic command executing unit.
5. The communication interface device according to claim 4, further comprising an interrupt issuing unit that, when the chain atomic command execution completion determining unit determines that all the chained atomic commands stored in the chain atomic command storage unit are executed, issues an interrupt to a processor of the first computer so that the processor starts processing of the received packet.
6. The communication interface device according to claim 4, further comprising a completion notification transmitting unit that, when the chain atomic command execution completion determining unit determines that all the chained atomic commands stored in the chain atomic command storage unit are executed, transmits a completion notification to the transmitting computer.
7. The communication interface device according to claim 4, further comprising a communication process executing unit that, when the chain atomic command execution completion determining unit determines that all the chained atomic commands stored in the chain atomic command storage unit are executed, executes a predetermined communication process onto the transmitting computer.
8. The communication interface device according to claim 4, further comprising:
a packet reception information storage unit that stores therein packet reception information that indicates that the packet is received from the transmitting computer; and
a packet reception information initializing unit that initializes the packet reception information in the packet reception information storage unit when the chain atomic command execution completion determining unit determines that all the chained atomic commands stored in the chain atomic command storage unit are executed.
9. The communication interface device according to claim 8, further comprising:
a chain atomic command designation aborting unit that, when another packet is received from the transmitting computer before the packet reception information initializing unit initializes the packet reception information, aborts the memory operation and designation of the atomic command performed by the chain atomic command designating unit; and
an atomic command aborting information transmitting unit that transmits information to the transmitting computer that indicates the designation of the atomic command being aborted by the chain atomic command designation aborting unit.
10. The communication interface device according to claim 9, further comprising a packet transmission retrying unit that retries packet transmission to the first computer when the information transmitted by the atomic command aborting information transmitting unit that indicates the designation of the atomic command being aborted is received from the first computer.
11. A communication method, to be executed on a first computer from among a plurality of computers in a parallel computer architecture, of receiving a packet from a transmitting computer and executing an operation associated with received packet, the communication method comprising:
storing a plurality of atomic commands to transmit a communication packet, each of the atomic commands being chained using an address that indicates a next chained atomic command in a chain atomic command storage unit;
conducting a memory operation in a memory of the first computer on the basis of the packet received from the transmission computer;
first designating including designating, from among the atomic commands stored in the chain atomic command storage unit, an atomic command by a pointer included in the packet received from the transmission computer;
first executing the atomic command designated at the first designating;
second designating an atomic command chained with the designated atomic command among the atomic commands stored in the chain atomic command storage unit; and
second executing the chained atomic command designated at the second designating.
12. A communication method according to claim 11, further comprising third designating an atomic command associated with the atomic command executed at the second executing from the chain atomic command storage unit and executing the atomic command designated at the third designating.
13. The communication method according to claim 11, wherein
the conducting includes conducting a memory operation in response to a packet transmitted by the first computer, and
the first designating includes designating, from among the atomic commands stored in the chain atomic command storage unit, the atomic command by a pointer included in the packet transmitted by the first computer.
14. The communication method according to claim 11, further comprising determining, every time a packet is received owing to the atomic command executed in association with a synchronous process at the second executing of each of a plurality of transmitting computers, whether a result of the memory operation conducted on the atomic command meets a predetermined condition, wherein
when it is determined at the determining that a result of the memory operation meets the predetermined condition, the first designating includes designating an atomic command associated by a pointer included in the received packet.
15. The communication method according to claim 11, further comprising determining whether all the chained atomic commands stored in the chain atomic command storage unit are executed at the second executing.
16. The communication method according to claim 15, further comprising issuing, when it is determined at the determining that all the chained atomic commands stored in the chain atomic command storage unit are executed, an interrupt to a processor of the first computer so that the processor starts processing of the received packet.
17. The communication method according to claim 15, further comprising transmitting, it is determined at the determining that all the chained atomic commands stored in the chain atomic command storage unit are executed, a completion notification to the transmitting computer.
18. The communication method according to claim 15, further comprising third executing including executing, when it is determined at the determining that all the chained atomic commands stored in the chain atomic command storage unit are executed, a predetermined communication process onto the transmitting computer.
19. The communication method according to claim 15, further comprising:
storing packet reception information that indicates that the packet is received from the transmitting computer in a packet reception information storage unit; and
initializing the packet reception information in the packet reception information storage unit when it is determined at the determining that all the chained atomic commands stored in the chain atomic command storage unit are executed.
20. The communication method according to claim 19, further comprising:
aborting, when another packet is received from the transmitting computer before the packet reception information is initialized at the initializing, the conducting and the first designating; and
transmitting information to the transmitting computer that indicates the first designating has been aborted at the aborting.
21. The communication method according to claim 20, further comprising retrying packet transmission to the first computer when the information transmitted at the transmitting that indicates the first designating being aborted is received from the first computer.
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 controlling at least one traction motor driving an axle on a vehicle wherein the vehicle includes a plurality of axles on which wheels are mounted, the method comprising:
determining whether at least one of the wheels on at least one of the axles differs in diameter from at least one other wheel on a different one of the axles by more than a threshold value; and
selectively increasing a torque provided by a traction motor driving an axle with at least one wheel that has a larger diameter than at least one other wheel on a different axle.
2. The method of claim 1, wherein determining whether a first one of the wheels on a first one of the axles differs in diameter from at least a second one of the wheels on a second one of the axles by more than a threshold value includes comparing an angular velocity of the first one of the wheels or the first one of the axles with an angular velocity of the second one of the wheels or the second one of the axles on the vehicle.
3. The method of claim 1, wherein determining whether at least one of the wheels on a first one of the axles differs in diameter from at least a second one of the wheels on a second one of the axles by more than a threshold value includes determining a slip frequency for a first traction motor driving the first one of the axles and a slip frequency for a second traction motor driving the second one of the axles.
4. The method of claim 3, wherein determining whether at least one of the wheels on a first one of the axles differs in diameter from at least a second one of the wheels on a second one of the axles by more than a threshold value includes:
determining an actual rotational frequency of a rotor for each of the respective first and second traction motors and a synchronous frequency of rotation of a magnetic field produced by stator windings of each of the respective first and second traction motors; and
comparing any difference between the actual rotational frequency of a rotor on the first traction motor and the synchronous frequency of rotation of a magnetic field produced by stator windings of the first traction motor with any difference between the actual rotational frequency of a rotor on the second traction motor and the synchronous frequency of rotation of a magnetic field produced by stator windings of the second traction motor.
5. The method of claim 3, wherein the first traction motor and the second traction motor are each supplied with substantially the same voltage and frequency while determining the slip frequency for the first traction motor and the slip frequency for the second traction motor.
6. The method of claim 4, wherein the first traction motor and the second traction motor are each supplied with substantially the same voltage and frequency while determining an actual rotational frequency of a rotor for each of the respective first and second traction motors and a synchronous frequency of rotation of a magnetic field produced by stator windings of each of the respective first and second traction motors.
7. The method of claim 1, further including:
determining a geographical location of the vehicle; and
decreasing a torque provided by a traction motor driving an axle with at least one wheel that is larger in diameter than at least one other wheel on a different axle when the vehicle is in a geographical location where an increase in pulling capabilities for the vehicle is desired.
8. The method of claim 1, wherein increasing torque provided by a traction motor includes controlling at least one of voltage, frequency, amplitude, and phase of current supplied to the traction motor by an inverter configured to receive DC current from a generator driven by an engine on the vehicle.
9. The method of claim 1, further including:
driving each of the plurality of axles on the vehicle with a separate traction motor; and
controlling the torque provided by each of the traction motors to each respective axle with a separate inverter for each of the traction motors.
10. The method of claim 1, wherein the threshold value is a function of at least one of regulations, historical norms, and empirical values that enable the vehicle to achieve operational goals.
11. A system for independently controlling individual axles of a plurality of axles on a vehicle based at least in part on the diameters of wheels mounted on each of the plurality of axles, the system comprising:
a separate traction motor coupled to each of the plurality of axles on the vehicle; and
a controller configured for:
determining whether at least one of the wheels mounted on at least one of the plurality of axles differs in diameter from at least one other wheel on a different one of the axles by more than a threshold value; and
increasing a torque provided by a traction motor driving an axle with at least one wheel that has a larger diameter than at least one other wheel on a different axle.
12. The system of claim 11, wherein the controller is further configured for:
determining whether a first one of the wheels on a first one of the axles differs in diameter from at least a second one of the wheels on a second one of the axles by more than a threshold value by comparing an angular velocity of the first one of the wheels or the first one of the axles with an angular velocity of the second one of the wheels or the second one of the axles on the vehicle.
13. The system of claim 11, wherein the controller is further configured for:
determining whether at least one of the wheels on a first one of the axles differs in diameter from at least a second one of the wheels on a second one of the axles by more than a threshold value by determining a slip frequency for a first traction motor driving the first one of the axles and a slip frequency for a second traction motor driving the second one of the axles.
14. The system of claim 13, wherein the controller is configured for determining whether at least one of the wheels on a first one of the axles differs in diameter from at least a second one of the wheels on a second one of the axles by more than a threshold value by:
determining an actual rotational frequency of a rotor for each of the respective first and second traction motors and a synchronous frequency of rotation of a magnetic field produced by stator windings of each of the respective first and second traction motors; and
comparing any difference between the actual rotational frequency of a rotor on the first traction motor and the synchronous frequency of rotation of a magnetic field produced by stator windings of the first traction motor with any difference between the actual rotational frequency of a rotor on the second traction motor and the synchronous frequency of rotation of a magnetic field produced by stator windings of the second traction motor.
15. The system of claim 13, wherein the controller is further configured for commanding a supply of substantially the same voltage and frequency to each of the first traction motor and the second traction motor while determining the slip frequency for the first traction motor and the slip frequency for the second traction motor.
16. The system of claim 14, wherein the controller is further configured for commanding a supply of substantially the same voltage and frequency to each of the first traction motor and the second traction motor while determining an actual rotational frequency of a rotor for each of the respective first and second traction motors and a synchronous frequency of rotation of a magnetic field produced by stator windings of each of the respective first and second traction motors.
17. The system of claim 11, wherein the controller is further configured for:
determining a geographical location of the vehicle; and
decreasing a torque provided by a traction motor driving an axle with at least one wheel that is larger in diameter than at least one other wheel on a different axle when the vehicle is in a geographical location where an increase in pulling capabilities for the vehicle is desired.
18. The system of claim 11, further including:
a separate inverter coupled to each of the separate traction motors; and wherein the controller is configured for controlling at least one of voltage, frequency, amplitude, and phase of current supplied to each of the separate traction motors by commands transmitted to each of the separate inverters.
19. The system of claim 11, wherein the controller is configured for determining the threshold value as a function of at least one of regulations, historical norms, and empirical values that enable the vehicle to achieve operational goals.
20. A mobile vehicle, comprising:
an electrical power source;
a plurality of axles;
at least a pair of wheels mounted on each of the plurality of axles;
a plurality of traction motors, each of the plurality of traction motors drivingly coupled to a separate one of the plurality of axles and electrically coupled to receive electrical power from the electrical power source;
a plurality of inverters, each of the plurality of inverters coupled to a separate one of the plurality of traction motors; and
a controller configured for:
determining whether at least one of the wheels mounted on at least one of the plurality of axles differs in diameter from at least one other wheel on a different one of the axles by more than a threshold value; and
increasing a torque provided by a traction motor driving an axle with at least one wheel that has a larger diameter than at least one other wheel on a different axle by increasing at least one of voltage and frequency supplied by an inverter to the traction motor in order to increase an amount of slip of the larger diameter wheel.