Apparatus and method for measuring and displaying performance characteristics of reciprocating piston machines
First Claim
1. Apparatus for measuring and displaying indicated power of a reciprocating piston machine, said apparatus comprising:
- a common data bus;
a common address bus;
a central processing unit operatively connected to said common data bus and said common address bus;
a decoder operatively connected to said address bus for providing enabling signals in response to predetermined addresses being placed on said address bus;
a read-only memory operatively connected to said common data bus and said common address bus and containing instructions for execution by the central processing unit, said read-only memory being capable of receiving enabling signals from said decoder;
a read/write memory operatively connected to said common data bus and said common address bus and being capable of temporary storage of data received from said data bus, said read/write memory being capable of receiving enabling signals from said decoder;
a keyboard assembly operatively connected to said common data bus and said common address bus and providing means for an operator to enter predetermined data onto the data bus for subsequent storage in said read/write memory, said predetermined data comprising connecting rod length, piston stroke and cylinder bore which are used in the calculation of a table of values proportional to the change in cylinder volume per degree of crankshaft rotation, said keyboard assembly being capable of receiving enabling signals from said decoder;
a display controller operatively connected to said common data bus and said common address bus and capable of providing controlling signals to a display device, said display controller being capable of receiving enabling signals from said decoder;
a display device operatively connected to receive said controlling signals from said display controller, said controlling signals being representative of predetermined display information including alphanumeric characters, curves and forms expressing physical or mathematical representations;
means for providing data that represent crankshaft angular position and angular velocity of said reciprocating piston machine to said central processing unit; and
means for providing data that represent cylinder pressure of said reciprocating piston machine to said central processing unit.
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Accused Products
Abstract
Apparatus and method are disclosed for measuring and displaying predetermined characteristics of reciprocating piston machines. In the preferred embodiment, the predetermined characteristics comprise indicated horsepower, crankshaft angle and piston position. The apparatus comprises a central processing unit, memory devices, keyboard assembly, display controller, display unit, sweep generator, pressure data acquisition and scaling system, shaft encoder and pressure transducer operatively connected by an address bus and a data bus to measure and display the predetermined characteristics. A method is provided whereby an electrical signal is generated which is proportional to the instantaneous position of a designated piston in the reciprocating piston machine. A method is also provided whereby an electrical signal is generated which is proportional to the instantaneous angular position of the crankshaft with respect to a top-dead-center position of a piston in a predetermined cylinder of the reciprocating piston machine. Predetermined data is entered into the apparatus by the operator as well as from the pressure transducer and crank angle or shaft encoder attached to the engine/compressor which is to be analyzed. The sweep generator circuitry maintains an accurate sweep length for the display unit over the entire range of speeds from zero to the top speed of the engine or compressor being analyzed.
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Citations
34 Claims
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1. Apparatus for measuring and displaying indicated power of a reciprocating piston machine, said apparatus comprising:
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a common data bus; a common address bus; a central processing unit operatively connected to said common data bus and said common address bus; a decoder operatively connected to said address bus for providing enabling signals in response to predetermined addresses being placed on said address bus; a read-only memory operatively connected to said common data bus and said common address bus and containing instructions for execution by the central processing unit, said read-only memory being capable of receiving enabling signals from said decoder; a read/write memory operatively connected to said common data bus and said common address bus and being capable of temporary storage of data received from said data bus, said read/write memory being capable of receiving enabling signals from said decoder; a keyboard assembly operatively connected to said common data bus and said common address bus and providing means for an operator to enter predetermined data onto the data bus for subsequent storage in said read/write memory, said predetermined data comprising connecting rod length, piston stroke and cylinder bore which are used in the calculation of a table of values proportional to the change in cylinder volume per degree of crankshaft rotation, said keyboard assembly being capable of receiving enabling signals from said decoder; a display controller operatively connected to said common data bus and said common address bus and capable of providing controlling signals to a display device, said display controller being capable of receiving enabling signals from said decoder; a display device operatively connected to receive said controlling signals from said display controller, said controlling signals being representative of predetermined display information including alphanumeric characters, curves and forms expressing physical or mathematical representations; means for providing data that represent crankshaft angular position and angular velocity of said reciprocating piston machine to said central processing unit; and means for providing data that represent cylinder pressure of said reciprocating piston machine to said central processing unit. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Apparatus for providing and displaying crankshaft angle and piston position related events of a reciprocating piston machine for the purpose of indicating possible need for preventative maintenance of said reciprocating piston machine, said apparatus comprising:
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a common data bus; a common address bus; a central processing unit operatively connected to said common data bus and said common address bus; a decoder operatively connected to said address bus for providing enabling signals in response to predetermined addresses being placed on said address bus; a read only memory operatively connected to said common data bus and said common address bus and containing instructions for execution by the central processing unit, said read only memory being capable of receiving enabling signals from said decoder; a read/write memory operatively connected to said common data bus and said common address bus and being capable of temporary storage of data received from said data bus, said read/write memory being capable of receiving enabling signals from said decoder; a keyboard assembly operatively connected to said common data bus and said common address bus and providing means for an operator to enter predetermined data onto the data bus for subsequent storage in said read/write memory, said keyboard assembly being capable of receiving enabling signals from said decoder; a display controller operatively connected to said common data bus and said common address bus and capable of providing controlling signals to a display device, said display controller being capable of receiving enabling signals from said decoder; a display device operatively connected to receive said controlling signals from said display controller, said controlling signals being representative of predetermined display information including alphanumeric characters, curves and forms expressing physical or mathematical representations; means for providing data to be used in the calculation of piston position of said reciprocating piston machine to said processing unit; means for providing data that represent crankshaft angular position and angular velocity of said reciprocating piston machine to said central processing unit; means for providing data that represent cylinder pressure of said reciprocating piston machine to said central processing unit; and a sweep generator system operatively connected to said common data bus and said common address bus and being responsive to a one pulse per degree signal received from an encoder means, a sweep reset signal received from the central processing unit and data generated by the central processing unit detailing piston position relative to top-dead-center to provide a first signal which is proportional to the position of the piston with respect to the top-dead-center position of the piston and a second signal which is proportional to the angular position of a crankshaft with respect to the position of the crankshaft when said piston is at its top-dead-center position, said sweep generator system being capable of receiving enabling signals from said decoder. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30)
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31. In apparatus for providing and displaying crank angle and piston position related events of a reciprocating piston machine for the purpose of indicating possible need for preventive maintenance of said reciprocating piston machine and including a common data bus, a common address bus, a decoder, a central processing unit, a read only memory, a read write memory, a keyboard assembly, a display device, a display controller, a sweep generator system, a pressure data acquisition and scaling system, set/reset flip flops and a timer,
an improved method of generating an electrical signal which is proportional to the instantaneous position of a piston in a predetermined cylinder with respect to the top-dead-center position in a cylinder, which signal can be used to present an accurate pictorial representation, on a display device, of the instantaneous piston position, comprising the steps of: -
entering the values of predetermined mechanical dimensions of a connecting rod and a crankshaft of the reciprocating piston machine on the keyboard assembly and transferring the values to predetermined locations in the read/write memory; calculating a table of piston position versus crank angle values and storing said values in predetermined locations in a read/write memory located in said sweep generator system; entering a top-dead-center setting input to a predetermined location in read/write memory from the keyboard assembly, said top-dead-center setting represents the value of the number of degrees of crank angle rotation which occurs between the time when a piston in a reference cylinder is at top-dead-center and when a piston in said predetermined cylinder is at top-dead-center; adjusting an encoder assembly opeatively positioned on said reciprocating piston machine such that a one pulse per revolution signal occurs when the piston in the reference cylinder is at top-dead-center; waiting for the occurrence of the one pulse per revolution signal to be sensed by the central processing unit; counting occurrences of a one pulse per degree signal which occurs after the sensing of the one pulse per revolution signal, said count being performed by the central processing unit under instructions from the read only memory; outputting a signal from the central processing unit to clear a counter in said sweep generator system when the number of occurrences of the one pulse per degree signal equals the top-dead-center setting; applying a one pulse per degree signal train to said counter to cause said counter to count one pulse per degree signals; applying the output of said counter to address inputs of said read/write memory, said output of said counter having a value equal to the count of the one pulse per degree signals applied since said counter was cleared; changing the output of said read/write memory in accordance with the changing value of the address inputs such that the output of said read/write memory is proportional to the position of the piston in said predetermined cylinder at the crank angle degree which said counter represents; applying the output of said read/write memory to a digital to analog converter; and changing the output signal from the digital to analog converter such that said output signal is proportional to the instantaneous position of the piston in a predetermined cylinder with respect to the top-dead-center position of said piston in said predetermined cylinder. - View Dependent Claims (32)
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33. In apparatus for providing and displaying crank angle and piston position related events of a reciprocating piston machine for the purpose of indicating possible need for preventive maintenane of said reciprocating piston machine and including a common data bus, a common address bus, a decoder, a central processing unit, a read only memory, a read write memory, a keyboard assembly, a display controller, a sweep generator system, a pressure data acquisition and scaling system, set/reset flip flops and a timer,
an improved method for generating an electrical signal which is proportional to the instantaneous angular position of the crankshaft with respect to a top-dead-center position of a piston in a predetermined cylinder, comprising the steps of: -
entering a top-dead-center setting input to a predetermined location in read/write memory from the keyboard assembly, said top-dead-center setting represents the value of the number of degress of crank angle rotation which occurs between the time when a piston in a reference cylinder is at top dead center and when a piston in said predetermined cylinder is at top dead center; adjusting an encoder assembly operatively positioned on said reciprocating piston machine such that a one pulse per revolution signal occurs when the piston in the reference cylinder is at top-dead-center; waiting for the occurrence of the one pulse per revolution signal to be sensed by the central processing unit; counting occurrences of a one pulse per degree signal which occurs after the sensing of the one pulse per revolution signal, said count being performed by the central processing unit under instructions from the read only memory; outputting a signal from the central processing unit to clear a counter in said sweep generator system when the number of occurrences of the one pulse per degree signal equals the top-dead-center setting; applying a one pulse per degree signal train to said counter to cause said counter to count one pulse per degree signals; applying the output of said counter to a digital to analog converter, said output having a value equal to the count of the one pulse per degree signals applied since said counter was cleared. changing the output signal from the digital to analog converter such that said output signal is proportional to the instantaneous angular position of the crankshaft with respect to the top-dead-center position of said piston in said predetermined cylinder. - View Dependent Claims (34)
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Specification