Electronic braking system with system test

An electronic braking system for multi-axle road vehicle, comprising:

• a foot-operable braking transducer for generating electrical braking demand signals representative of a driver's braking demand,
• load transducer means for generating electrical load signals representative of a respective load on different axles of the vehicle,
• an electronic controller which receives said braking demand signals and load signals and generates electrical output signals for controlling operation of braking devices for wheels carried by said axles,
• said controller including adaptive load compensation means which act to modify said output signals of said controller to said various braking devices so as to take account of prevailing loads on said axles,
• test mode control means enabling said system to enter a test mode,
• test demand application means for automatically applying to said controller in said test mode and in place of said electronic braking demand signals representative of driver braking demand, a preset standard braking input demand, and
• gradient detection means for providing said controller with a gradient correction signal representative of a gradient on which the vehicle is disposed, and
• to enable gradient correction to be tested under preset axle load conditions by comparison of braking pressures produced in a level position against those produced in a given gradient attitude with the same automatically generated preset demand (DF), the system further includes attitude establishing means for establishing a predetermined attitude signal automatically upon an alternative test sub mode being entered even though the vehicle may remain level, said predetermined attitude signal being introduced to said controller in place of said gradient correction signal to provide a simulated gradient correction signal equivalent to that which would be produced on a predetermined gradient by said detection means.

An electronic braking system for a multi-axle road vehicle, comprising:

• a foot-operable braking transducer for generating electrical braking demand signals respective of a driver's braking demand,
• load transducer means for generating electrical load signals representative of the receptor load on different axles of the vehicle,
• an electronic controller which receives the braking demand signals and load signals and generates electrical output signals for controlling the operation of braking devices for wheels carried by said axles,
• said controller including load compensation means which act to modify said output signals of the controller to the various braking devices so as to take account of prevailing loads on the respective axles,
• means enabling the system to enter a test mode, and means for automatically applying to said controller in said test mode and in place of said electrical braking demand, a preset standard braking input demand, so that the system statically generates compensated braking pressures which take into account the prevailing values of axle load, to enable the latter pressures to be compared with standard figures issued for the vehicle type for at least two predetermined conditions of applied load.