We claim:
1. A control unit (110) to adapt engine torque during change in road gradient,
said control unit (110) connected to an engine speed sensor (102), and fuel injection and ignition system (108), said control unit (110) configured to : detect deviation between an actual engine speed and a set engine speed, and
process said deviation through a Proportional controller (112) and an Integral controller (114) to adapt engine torque corresponding to said set engine speed, characterized by
modulate an output of said Proportional controller (112) by a factor, on detection of conditions related to said deviation and an incremented value of said integral controller (114).
2. The control unit (110) as claimed in claimed 1, wherein detection of said
conditions comprises,
said deviation greater than said threshold deviation for a predetermined time, and
said incremented value of said Integral controller (114) greater than said limit value for said predetermined time.
3. The control unit (110) as claimed in claim 1, wherein a gear sensor (104) is used along with said deviation to adapt engine torque corresponding to said set engine speed.
4. The control unit (110) as claimed in claim 1, wherein said factor is selected from a map (118) stored in a memory element (116), said map (118) comprises factors based on said deviation and said incremented value of said integral controller (114).

5. The control unit (110) as claimed in claim 1, wherein said set engine speed is selected from a group comprising an idle creep speed, a cruise speed and a user defined speed.
6. A method for adapting engine torque during change in road gradient, said method comprising the steps of:
detecting deviation between an actual engine speed and a set engine speed, and
processing said deviation through a Proportional controller (112) and an Integral controller (114) to adapt an engine torque corresponding to set engine speed, characterized by modifying an output of said Proportional controller (112) by a factor, after detecting conditions related to said deviation and an incremented value of said integral controller (114).
7. The method as claimed in claimed 6, wherein detecting conditions
comprises,
detecting said deviation greater than said threshold deviation for a predetermined time, and
detecting said incremented value of said Integral controller (114) greater than said limit value for said predetermined time.
8. The method as claimed in claim 6, wherein a gear sensor (104) is used along with said deviation to adapt engine torque corresponding to said set engine speed.
9. The method as claimed in claim 6, wherein said factor is selected from a map (118) stored in a memory element (116), said map (118) comprises factors based on said deviation and said incremented value of said integral controller (114).

10. The method as claimed in claim 6, wherein said set engine speed is selected from a group comprising an idle creep speed, a cruise speed and a user defined speed.