All braking systems must meet a wide range of legislation. It varies depending on the vehicle type, selling territory, manufactuing volume, selling date etc. This is a brief shapshot of some of the legislation that may be applicable in Europe.
LEGISLATION
Before we go to deep into system design we need to consider legislation.
Most road going vehicles in Europe and beyond must be “Type Approved” (design and performance checked) before being sold to the public. To that end they are classified by type.
Category L – Motor vehicles with less than four wheels
Category M - Power-driven vehicles having at least four wheels and used for the carriage of passengers
Category N - Power-driven vehicles having at least four wheels and used for the carriage of goods
Category O - Trailers (including semi–trailers)
Prior to Brexit there were four type approval systems but now the UK has left the EU, the system is a mess with Great Britain (England, Scotland and Wales) having their own system and Northern Ireland having another, based on the EU system.
CAR BRAKING LEGISLATION
Passenger Car braking performance must comply with ECE R13H, H indicates ‘harmonised’ and is a world standard with the exception of the US and Canada.
The US have their own standards, FMVSS105 for cars and 121 for trucks.
This regulation is constantly being updated, for example stability control became mandatory for all vehicles in November 2014.
(This part at least is standardised across the world through Global Technical Regulation 8 and is the same as FMVSS126).
The entry into force of vehicle legislation is set by national government, in the UK the VCA website usually shows the dates but organisations such as the SMMT give more details to their members.
(ECE is the United Nations Economic Commission for Europe, which is similar to the European Community but includes more countries).
OTHER BRAKING LEGISLATION
ECE R13 covers other M and N category vehicles.
Though many M3, N3 & N2 vehicles over 8 tonnes also have to comply with ECE131 for Advanced Emergency Braking Systems.
Motorcycles and quads are approved to (EU) 168/2013 (even in the UK)
Tractors and forestry vehicles are approved to (EU) 2015/68 (even in the UK)
None road machines (they can still use the road) such as Backhoe Loaders, Dump Trucks etc. must comply with the Machinery Directive with is implemented into law in the UK by The Supply of Machinery (Safety) Regulations 2008 this lists a number of Brake Test Standards which should be followed. ISO3450:2011 is the most widely used.
There’s also lot’s of other legislation, not specifically braking that does affect the brake system…
Regulation (EC) No 78/2009 mandated the use of Brake Assist Systems in 2011 on the grounds of pedestrian safety.
WHAT IS A BRAKING SYSTEM?
ECE R13H defines "Braking equipment" as the combination of parts whose function is progressively to reduce the speed of a moving vehicle or bring it to a halt, or to keep it stationary if it is already halted. The equipment consists of the control, the, transmission, and the brake proper.
BRAKE PROPER?
And the “brake proper” as the part in which the forces opposing the movement of the vehicle develop. It may be a friction brake (when the forces are generated by friction between two parts of the vehicle moving relatively to one another); an electrical brake (when the forces are generated by electro-magnetic action between two parts of the vehicle moving relatively to but not in contact with one another); a fluid brake (when the forces are generated by the action of a fluid situated between two parts of the vehicle moving relatively to one another); or an engine brake (when the forces are derived from an artificial increase in the braking action, transmitted to the wheels, of the engine).
REQUIREMENTS BENCHMARKING
Legislation will give you the minimum requirement for a vehicle to be approved but that does not mean it will be acceptable to the customer. A good example being the required pedal force; a driver will expect a force several magnitudes lower that the legislation and almost certainly wouldn't buy a vehicle with such a heavy pedal. Pedal travel, another driver interface isn't mentioned in legislation but all would agree is a very important customer requirement.
Understanding your competition and customer requirments is vital to good system design.