1. An internal combustion engine comprising:
a control system;
a fuel system that draws liquid fuel from a fuel tank to charge fuel injectors that when actuated by the control system force fuel charges into engine combustion chambers using hydraulic fluid at injection control pressure (ICP); and
the control system comprising a processor for executing an ICP control strategy, wherein the strategy comprises processing a first fuel value indicative of the quantity of fuel presently in the tank and a second fuel value representing a quantity of fuel in the tank at which a maximum ICP limit set by the ICP control strategy should be changed, and when the result of the processing discloses that the second fuel value is less than the first fuel value, execution of the ICP control strategy reduces the maximum ICP limit from a greater value to a lesser value.
2. An engine as set forth in claim 1 wherein execution of the ICP control strategy conditions reduction of the maximum ICP limit from the greater value to the lesser value on the second fuel value being continuously less than the first fuel value for a defined length of time.
3. An engine as set forth in claim 1 wherein execution of the ICP control strategy restores the maximum ICP limit from the lesser value to the greater value when the result of the processing discloses that the second fuel value ceases to be less than the first fuel value.
4. An engine as set forth in claim 3 wherein execution of the ICP control strategy conditions restoration of the maximum ICP limit from the lesser value to the greater value on the second fuel value continuously ceasing to be less than the first fuel value for a defined length of time.
5. An engine as set forth in claim 1 comprising a switch function having inputs whose values correspond respectively to the greater and the lesser values of the maximum ICP limit, and wherein the switch function is controlled by the result of processing the first and second fuel values.
6. A fuel system and a control system for an internal combustion engine:
wherein the fuel system draws liquid fuel from a fuel tank to charge fuel injectors that when actuated by the control system force fuel charges into engine combustion chambers using hydraulic fluid at injection control pressure (ICP); and
wherein the control system comprises a processor for executing an ICP control strategy that comprises processing a first fuel value indicative of the quantity of fuel presently in the tank and a second fuel value representing a quantity of fuel in the tank at which a maximum ICP limit set by the ICP control strategy should be changed, and when the result of the processing discloses that the second fuel value is less than the first fuel value, causing the maximum ICP limit to be reduced from a greater value to a lesser value.
7. A fuel system and a control system as set forth in claim 6 wherein execution of the ICP control strategy conditions reduction of the maximum ICP limit from the greater value to the lesser value on the second fuel value being continuously less than the first fuel value for a defined length of time.
8. A fuel system and a control system as set forth in claim 6 wherein execution of the ICP control strategy restores the maximum ICP limit from the lesser value to the greater value when the result of the processing discloses that the second fuel value ceases to be less than the first fuel value.
9. A fuel system and a control system as set forth in claim 8 wherein execution of the ICP control strategy conditions restoration of the maximum ICP limit from the lesser value to the greater value on the second fuel value continuously ceasing to be less than the first fuel value for a defined length of time.
10. A fuel system and a control system as set forth in claim 6 comprising a switch function having inputs whose values correspond respectively to the greater and the lesser values of the maximum ICP limit, and wherein the switch function is controlled by the result of processing the first and second fuel values.
11. A method for control of injection control pressure (ICP) that is used to force the injection of fuel into an engine combustion chamber comprising:
processing a first fuel value indicative of the quantity of fuel presently in a fuel tank and a second fuel value representing a quantity of fuel in the tank at which a maximum ICP limit should be changed, and when the result of the processing discloses that the second fuel value is less than the first fuel value, causing the maximum ICP limit to be reduced from a greater value to a lesser value.
12. A method as set forth in claim 11 comprising conditioning reduction of the maximum ICP limit from the greater value to the lesser value on the second fuel value being continuously less than the first fuel value for a defined length of time.
13. A method as set forth in claim 11 comprising restoring the maximum ICP limit from the lesser value to the greater value when the result of the processing discloses that the second fuel value ceases to be less than the first fuel value.
14. A method as set forth in claim 13 comprising conditioning restoration of the maximum ICP limit from the lesser value to the greater value on the second fuel value continuously ceasing to be less than the first fuel value for a defined length of time.
15. A method as set forth in claim 11 comprising controlling a switch function by the result of processing the first and second fuel values to cause the switch function to pass one of the greater and the lesser values of the maximum ICP limit to the exclusion of the other based on the result of processing the first and second fuel values.
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 measuring the elasticity of crystalline lens for measuring stiffness of the crystalline lens,
wherein the crystalline lens is irradiated with pulse laser light to generate photoelastic waves from the crystalline lens, and the photoelastic waves from the crystalline lens are measured whereby a damping factor of the crystalline lens is calculated,
the crystalline lens is irradiated with interference laser light to generate interference fringe by the photoelastic waves, and elastic modulus of the crystalline lens is calculated based on variation in the interference fringe, and
a wavelength of the pulse laser light is set such that light transmission in the crystalline lens becomes 20% or lower.
2. The method according to claim 1, wherein a wavelength of the pulse laser light is set in a range of 1,400 nm to 2,600 nm.
3. A method of determining whether crystalline lens is presbyopic, wherein elastic modulus of the crystalline lens is calculated by the method according to claim 1, and presbyopia caused by advancing age of the crystalline lens is determined from the calculated elastic modulus.
4. An apparatus for measuring the elasticity of crystalline lens for measuring stiffness of the crystalline lens, comprising:
a pumping laser for irradiating the crystalline lens with pulse laser light,
an interference laser for irradiating the crystalline lens with interference laser light,
a detector for measuring photoelastic waves from the crystalline lens,
a calculating unit for calculating elastic modulus of the crystalline lens, and
a display unit for displaying the elastic modulus calculated by the calculating unit,
wherein the photoelastic waves from the crystalline lens are measured whereby a damping factor of the crystalline lens is calculated.
5. An apparatus for determining whether crystalline lens is presbyopic for determining presbyopia caused by advancing age of the crystalline lens, comprising
a pumping laser for irradiating the crystalline lens with pulse laser light,
an interference laser for irradiating the crystalline lens with interference laser light,
a detector for measuring photoelastic waves from the crystalline lens,
a calculating unit for calculating elastic modulus of the crystalline lens,
a presbyopia determining unit for determining the presbyopia caused by advancing age of the crystalline lens from the elastic modulus calculated by the calculating unit, and
a display unit for displaying the elastic modulus calculated by the calculating unit and determination of presbyopia made by the presbyopia determining unit.