Control of pre-scr ammonia dosing based on look-ahead data

A method for controlling an exhaust gas aftertreatment system, wherein the exhaust gas aftertreatment system comprises

• a first reducing agent dosing device;
• a first selective catalytic reduction (SCR) device arranged downstream of the first reducing agent dosing device;
• a catalytic particulate filter arrangement arranged downstream of the first SCR device, wherein the catalytic particulate filter assembly comprises a catalysed particulate filter, or wherein the catalytic particulate filter assembly comprises an oxidation catalyst and a particulate filter arranged downstream of the oxidation catalyst;
• a second reducing agent dosing device arranged downstream of the catalytic particulate filter arrangement;
• and
• a second selective catalytic reduction (SCR) device arranged downstream of the second reducing agent dosing device;
• and wherein the method comprises the steps of:
• estimating future exhaust conditions based upon predicted vehicle operating conditions (s403);
• estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405);
• and
• dosing a reducing agent from the first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).