1. An apparatus for controlling an engine using a cam signal in addition to a crank signal, the cam signal including a series of changes between high and low levels in a predetermined waveform pattern, same directed edges of the changes of the cam signal corresponding to angular positions of rotation of a camshaft of the engine, the crank signal including a train of crank pulses whose same-directed edges correspond to angular positions of rotation of a crankshaft of the engine, the angular positions of rotation of the camshaft being associated with those of rotation of the crankshaft, the apparatus comprising:
an edge interval measuring unit configured to receive an input signal including a series of changes between high and low levels and to measure an edge interval of temporally adjacent same-directed edges of the input signal;
an input unit configured to input the crank signal as the input signal to the edge interval measuring unit, the edge interval measuring unit measuring one of edge intervals of temporally adjacent same-directed edges of the crank signal;
a multiplication clock signal generating unit configured to generate a multiplication clock signal including a train of clock pulses whose clock cycle is an integral number submultiple of the measured edge interval;
a count unit configured to count in synchronization with the multiplication clock signal;
an abnormality determining unit configured to determine whether the crank signal is abnormal;
a switching unit configured to switch the input signal to the edge interval measuring unit from the crank signal to the cam signal when it is determined that the crank signal is abnormal, the edge interval measuring unit measuring an edge interval of temporally adjacent same-directed edges of the cam signal; and
a count-value control unit configured to:
identify the angular positions of the crankshaft based on the cam signal to initialize a count value of the count unit based on the identified angular positions of the crankshaft; and
change the integral number based on the predetermined waveform pattern of the cam signal to shift the count value of the count unit as in the case of the crank signal inputting to the edge interval measuring unit.
2. An apparatus according to claim 1, wherein the switching unit is configured to generate an edge-synchronized signal rising when a level change appears in the cam signal and to switch the input signal to the edge interval measuring unit from the crank signal to the edge-synchronized signal as the cam signal.
3. An apparatus according to claim 1, wherein the cam shaft consists of first and second cam shafts so that the cam signal consists of first and second cam signals, and the switching unit is configured to OR the first and second cam signals and to switch the input signal to the edge interval measuring unit from the crank signal to the ORed signal of the first and second cam signals as the cam signal.
4. An apparatus according to claim 3, wherein the switching unit is configured to:
generate a first edge-synchronized signal rising when a level change appears in the first cam signal;
generate a second edge-synchronized signal rising when a level change appears in the second cam signal;
OR the first and second edge-synchronized signals; and
switch the input signal to the edge interval measuring unit from the crank signal to the ORed signal of the first and second edge-synchronize signals as the cam signal in place of the ORed signal of the first and second cam signals.
5. An apparatus according to claim 3, wherein the switching unit is configured to switch the input signal to the edge interval measuring unit from the crank signal to any one of the first cam signal, the second cam signal, and the ORed signal of the first and second cam signals as the cam signal, the abnormality determining unit is configured to determine whether each of the crank signal, the first cam signal, and the second cam signal is abnormal, the switching unit switching:
the input signal to the edge interval measuring unit from the crank signal to the ORed signal of the first and second cam signals as the cam signal when it is determined that the first and second cam signals are normal but the crank signal is abnormal,
the input signal to the edge interval measuring unit from the crank signal to the first cam signal as the cam signal when it is determined that the crank signal and the second cam signal are abnormal but the first cam signal is normal, and
the input signal to the edge interval measuring unit from the crank signal to the second cam signal as the cam signal when it is determined that the crank signal and the first cam signal are abnormal but the second cam signal is normal, and wherein the count value control unit is configured to:
identify the angular positions of the crankshaft based on at least one of the first and second cam signals, initialize the count value of the count unit based on the identified angular positions of the crankshaft, and change the integral number based on the predetermined waveform pattern of the ORed signal of the first and second cam signals to shift the count value of the counter as in the case of the crank signal inputting to the edge interval measuring unit when the ORed signal is input to the edge interval measuring unit,
identify the angular positions of the crankshaft based on the first cam signal, initialize the count value of the count unit based on the identified angular positions of the crankshaft, and change the integral number based on the predetermined waveform pattern of the first cam signal to shift the count value of the counter as in the case of the crank signal inputting to the edge interval measuring unit when the first cam signal is input to the edge interval measuring unit, and
identify the angular positions of the crankshaft based on the second cam signal, initialize the count value of the count unit based on the identified angular positions of the crankshaft, and change the integral number based on the predetermined waveform pattern of the second cam signal to shift the count value of the counter as in the case of the crank signal inputting to the edge interval measuring unit when the second cam signal is input to the edge interval measuring unit.
6. An apparatus according to claim 5, wherein the switching unit is configured to:
generate a first edge-synchronized signal rising when a level change appears in the first cam signal;
generate a second edge-synchronized signal rising when a level change appears in the second cam signal;
OR the first and second edge-synchronized signals; and
switch the input signal to the edge interval measuring unit from the crank signal to any one of the first edge-synchronized signal as the first cam signal, the second edge-synchronized signal as the second cam signal, and the ORed signal of the first and second edge-synchronize signals as the ORed signal of the first and second cam signals as the cam signal.
7. An apparatus according to claim 1, wherein the crank signal includes a pulse-missing portion corresponding to pulse interval in which a predetermined number of crank pulses are skipped, the pulse-missing portion indicating a predetermined angular position of the crankshaft, and the cam signal includes a first series of changes from high and low levels in a first predetermined waveform pattern, the first series of changes appearing before the crankshaft is located at the predetermined angular position, and a second series of changes from high and low levels in a second predetermined waveform pattern, the second series of changes appearing after the crankshaft is located at the predetermined angular position, the first waveform pattern being different from the second waveform pattern.
8. An apparatus according to claim 1, wherein the count-value control unit is configured to cause the count unit to wrap around within a predetermined angular range of the crankshaft as in the case of the crank signal inputting to the edge interval measuring unit.
9. An apparatus according to claim 1, wherein the count-value control unit is configured to prevent the counting during each of the edge intervals in the cam signal.
10. A method of controlling an engine using a cam signal in addition to a crank signal, the cam signal including a series of changes between high and low levels in a predetermined waveform pattern, same directed edges of the changes of the cam signal corresponding to angular positions of rotation of a camshaft of the engine, the crank signal including a train of crank pulses whose same-directed edges correspond to angular positions of rotation of a crankshaft of the engine, the angular positions of rotation of the camshaft being associated with those of rotation of the crankshaft, the method comprising:
when receiving an input signal including a series of changes between high and low levels, measuring an edge interval of temporally adjacent same-directed edges of the input signal;
inputting the crank signal as the input signal to the measuring step, the measuring step measuring one of edge intervals of temporally adjacent same-directed edges of the crank signal;
generating a multiplication clock signal including a train of clock pulses whose clock cycle is an integral number submultiple of the measured edge interval;
counting in synchronization with the multiplication clock signal;
determining whether the crank signal is abnormal;
switching the input signal to the edge interval measuring unit from the crank signal to the cam signal when it is determined that the crank signal is abnormal, the measuring step measuring an edge interval of temporally adjacent same-directed edges of the cam signal;
identifying the angular positions of the crankshaft based on the cam signal to initialize a count value of the count unit based on the identified angular positions of the crankshaft; and
changing the integral number based on the predetermined waveform pattern of the cam signal to shift the count value as in the case of the crank signal inputting to the measuring step.
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 of producing a bio-diesel oil, comprising:
(a) pre-esterifying a free fatty acid, contained in oilfat, with an alcohol in the presence of an acidic catalyst to create a reaction mixture comprising an alkyl ester; and
(b) transesterifying the reaction mixture to create a product comprising the alkyl ester,
wherein a portion of the product comprising the alkyl ester produced by the step (b) is directly recycled to the reaction mixture of step (a) andor step (b) prior to separating the alkyl ester and glycerine in a separator.
2. The method as set forth in claim 1, wherein the step (a) further comprises adding alkyl ester as a product to the reactants.
3. The method as set forth in claim 1 or 2, wherein the alkyl ester of the step (a) orand the step (b) is added to the reactants in an amount of 1 to 30% based on a weight of the oilfat.
4. The method as set forth in claim 1, wherein the oilfat of the step (a) is selected from the group consisting of vegetable oilfat, animal oilfat, waste frying oil, and regenerated oilfat, containing the free fatty acid.
5. The method as set forth in claim 1, wherein the alcohol of the step (a) and the step (b) is selected from the group consisting of C1 to C10 alcohols, and a mixture thereof.
6. The method as set forth in claim 1, wherein the oilfat containing the free fatty acid reacts with the alcohol in a molar ratio of 1:0.3 to 1:3 in the step (a), and the oilfat reacts with the alcohol in a molar ratio of 1:3 to 1:12 in the step (b).
7. The method as set forth in claim 1, wherein the step (b) is conducted in a presence of a basic catalyst or the acidic catalyst.
8. The method as set forth in claim 7, wherein the basic catalyst or acidic catalyst is a homogeneous catalyst, and is added to reactants in an amount of 0.3 to 2.0% based on a weight of oilfat.
9. The method as set forth in claim 7, wherein the basic catalyst or acidic catalyst is a heterogeneous catalyst, and is added to reactants in an amount of 5 to 80% based on a volume of a reactor.
10. The method as set forth in claim 1, wherein the step (a) and the step (b) are conducted in a batch reactor, a plug flow reactor, or a continuous stirred tank reactor, and when a plurality of reactors are used to conduct the step (a) and the step (b), the reactors are arranged in series, in parallel, or in combination of series and parallel.