Detail of GB/T 5620-2020

Introduction of GB/T 5620-2020

This standard is developed in accordance with the rules given in GB/T 1.1-2009. This standard replaces GB/T 5620-2002 Road vehicles - Braking of automotive vehicles and their trailers - Vocabulary. The following main technical changes have been made with respect to GB/T 5620-2002: ——endurance braking system and its control device are added for the braking system (see 3.2.4); ——the terms and definitions of braking systems relating to transmission means are added (see 4.2); ——relevant terms of brake components are moved to Clause 5 (see 5.5.1, and Clause 9 of 2002 edition); ——the terms and definitions of "Categories of retarder” and “auxiliary device consuming energy” are added (see 5.5.3.1 and 5.14); ——the term and definition of “non-continuous braking system” are deleted (see 5.3.5 of 2002 edition); ——the definition of “retarder” is modified (see 5.5.3 and 4.5.3 in 2002 edition); ——the terms and definitions of “engine braking”, “exhaust retarder”, “hydrodynamic retarder”, “hydrostatic retarder”, “permanent-magnetic retarder”, “regenerative braking retarder”, “mechanical regenerative braking retarder” are added (see 5.5.3.2.1, 5.5.3.2.3, 5.5.3.2.5.1, 5.5.3.2.5.2, 5.5.3.2.6.2, 5.5.3.2.6.3, 5.5.3.2.7); ——the term and definition of “friction retarder” are deleted (see. 4.5.3.6 of 2002 edition); ——the terms and definitions of “traction control system”, “stability control system”, “brake hold and release aid”, “autonomous intelligent cruise control system” and “coupling force control system” are added (see 6.2, 6.3, 6.4, 6.5, 6.6); ——relevant terms of the appearance of brake lining are moved to Clause 7 (see 7.1, and 9.5 of 2002 edition); ——the terms and definitions of “brake application”, “brake actuation”, “brake release”, “actuation threshold”, “clamping”, “brake release position”, “braking performance”, “braking slip”, “friction force coefficient”, “adhesion utilization”, “compatibility” are added (see 9.2, 9.3, 9.4, 9.5, 9.6, 9.7, 9.8, 9.18, 9.19, 9.20, 9.21); ——the terms related to pressure are listed separately, and the terms such as "cut-out pressure" and "cut-in pressure” are added (see Clause 10, and 6.4 of 2002 edition); ——the terms and definitions of “graduated braking”, “automatic braking”, “automatically commanded braking”, “selective braking”, “predominance”, “running clearance”, “circuit”, “braking modulation” are added (see Clause 11). This standard is identical to ISO 611: 2003 Road vehicles - Braking of automotive vehicles and their trailers - Vocabulary. The Chinese documents consistent and corresponding with the normative international documents in this standard are as follows: ——GB/T 3730.1- 2001 Motor vehicles and trailers - Types - Terms and definitions (ISO 3833: 1977, MOD) The following editorial changes have been made in this standard: ——the standard name is changed to Road vehicles - Vocabulary and definition for braking of automotive vehicles and their trailers ——the definitions of some terms are rewritten according to Chinese expression habits. This standard was proposed by the Ministry of Industry and Information Technology of the People's Republic of China. This standard is under the jurisdiction of the National Technical Committee of Auto Standardization (SAC/TC 114). The previous editions of this standard are as follows: ——GB/T 5620.1-1985, GB/T 5620.2-1985; ——GB/T 5620-2002. Road vehicles Vocabulary and definition for braking of automotive vehicles and their trailers 1 Scope This standard defines the principal terms used in relation to the braking and braking equipment of motor vehicles and their trailers as defined in ISO 3833. This standard it is applicable the systems or elements involved during the operation of braking, or the values characterizing the whole or a part of the operation. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 3833: 1977 Road vehicles - Types - Terms and definitions ISO/TR 13487: 1997 Braking of road vehicles - Consideration on the definition of mean fully developed deceleration 3 Braking systems and equipment - General 3.1 braking equipment all braking systems fitted to a vehicle 3.2 braking system combination of parts which fulfill one or more of the following functions: ——control (usually to reduce) a vehicle’s speed, ——bring the vehicle to a halt or hold it stationary 3.2.1 service braking system braking system allowing the driver to control, directly or indirectly and in a graduated manner, the speed of a vehicle during normal driving or to bring the vehicle to a halt 3.2.2 secondary braking system braking system allowing the driver to control, directly or indirectly and in a graduated manner, the speed of a vehicle or to bring the vehicle to a halt in case of failure of the service braking system 3.2.3 parking braking system braking system allowing a vehicle to be held stationary mechanically, even on an inclined surface, particularly in the absence of the driver 3.2.4 endurance braking system sum of all devices in a vehicle which enable the driver, virtually without friction brake wear and tear, to reduce the speed or to travel a long descent at nearly constant speed; it may contain multiple retarders Note: An endurance braking system may include ——energy supplying device(s); ——control device(s); ——transmission device(s), ——energy dissipation device(s), and ——auxiliary device(s). 3.2.4.1 Types of endurance braking system control devices 3.2.4.1.1 independent control device device controlling the endurance braking system independently from the service braking system 3.2.4.1.2 integrated control device device integral to the service braking system control device such that both endurance and service braking systems are applied simultaneously or suitably phased in operation 3.2.4.1.3 cut-out device device preventing the operation of the endurance braking system from being linked to the operation of the service braking system 3.2.4.2 retarder See 5.5.3. 4 Categories of braking system 4.1 Braking systems relating to their energy supplying device 4.1.1 muscular energy braking system braking system in which the energy necessary to produce the braking force is supplied solely by the physical effort of the driver 4.1.2 power-assisted braking system/energy-assisted braking system braking system in which the energy necessary to produce the braking force is supplied by the physical effort of the driver assisted by one or more energy-supplying device(s), for example, vacuum-assisted braking system (with vacuum booster), power hydraulic-assisted braking system (with hydraulic booster) 4.1.3 non-muscular energy braking system full-power braking system braking system in which the energy necessary to produce the braking force is supplied by one or more energy-supplying device(s) excluding the physical effort of the driver, for example, full-air braking system, full-power hydraulic braking system, air-over-hydraulic braking system Note: A braking system in which the driver can generate braking force in a failed energy condition by muscular effort acting on the system is excluded from the definition. 4.1.4 inertia braking system (trailer) braking system in which the energy necessary to produce the braking force arises from the thrust generated by a trailer approaching its towing vehicle 4.1.5 gravity braking system (trailer) braking system in which the energy necessary to produce the braking force arises from the lowering of an element of a trailer mass under the influence of gravity 4.1.6 spring braking system braking system in which the energy required for braking is supplied by one or more compressed springs acting as an energy storage accumulator 4.2 Braking systems relating to transmission means 4.2.1 mechanical braking system braking system in which the control and energy are transmitted from the point of application to the brake(s) by mechanical means such as levers, rods or cables 4.2.2 hydraulic braking system braking system in which the control and energy are transmitted from the point of application to the brake(s) by hydraulic transmission devices 4.2.3 pneumatic braking system braking system in which the control and energy are transmitted from the point of application to the brake(s) by hydraulic transmission devices Note: Two systems are possible: compressed air braking system and vacuum braking system. 4.2.4 air-over-hydraulic braking system braking system having stored pneumatic energy, hydraulically actuated brakes and transmission means incorporating a pneumatic-to-hydraulic converter 4.2.5 electric braking system braking system in which the actuating forces for the brake(s) are primarily produced by electric motors, responding to electrical transmission signals 4.2.6 electronic braking system; EBS braking system in which the control is generated and processed as an electrical signal in the control transmission, where an electrical output signal controls devices which produce the actuation forces 4.3 Braking systems relating to arrangement of transmission means 4.3.1 single-circuit braking system braking system having a transmission employing a single circuit so that in the event of a failure of this transmission, no energy for the production of the actuation force can be transmitted 4.3.2 dual-circuit braking system braking system having a transmission employing two separate circuits so that in the event of a failure of one transmission circuit, the second circuit remains able to control and transmit the energy necessary to generate the actuation force to those brake(s) connected to the system 4.3.3 multi-circuit braking system braking system having a transmission employing several separate circuits so that in the event of a failure of one transmission circuit, the other circuits remain able to control and transmit the energy necessary to generate the actuation force to those brake(s) connected to the system 4.4 Braking systems relating to vehicle combination 4.4.1 single-line braking system braking system that uses a single connection line both for the energy supply to, and for controlling the braking system of, a towed vehicle 4.4.2 two-line or multi-line braking system braking system that uses two or more connection lines separately, but simultaneously, for the energy supply to, and for controlling the braking system of, a towed vehicle 4.4.3 continuous braking system combination of braking systems for vehicles forming a vehicle combination characterized by the following: ——the driver, from the driving seat, may graduate, by the single operation of a directly operated control device on the towing vehicle, an indirectly operated control device on the towed vehicle; ——the energy necessary to produce the braking force of each of the vehicles forming the combination is supplied by the same energy source (which may be the muscular effort of the driver); ——simultaneous or suitably phased braking is applied to each of the vehicles forming the combination 4.4.4 semi-continuous braking system combination of braking systems for vehicles forming a vehicle combination characterized by the following: ——the driver, from the driving seat, can graduate, by the single operation of a directly operated control device on the towing vehicle, an indirectly operated control device on the towed vehicle; ——the energy necessary to produce the braking force of each of the vehicles forming the combination is supplied by at least two different energy sources (one of which may be the muscular effort of the driver); ——simultaneous or suitably phased braking is applied to each of the vehicles forming the combination 5 Braking system components Note: A braking system consists of connected devices which supply energy, control and transmit that energy to the brakes and, if necessary, via supplementary devices on the towing vehicle, to the brakes of a towed vehicle. 5.1 energy-supplying device part of a braking system which supplies, regulates and, if necessary, conditions the energy required for braking, and which terminates at the point where the transmission device starts, i.e. where the various circuits of the braking systems, including the circuits of accessories if fitted, are protected either from the energy-supplying device or from each other Note: This is also applicable to towed vehicles. 5.2 energy source part of the energy-supplying device which generates the energy Note: It may be located away from the vehicle (e.g. in the case of a compressed air braking system for a trailer) but may, in the simplest systems, be the muscular strength of the driver. 5.3 control device part of a braking system which initiates its operation and controls its output, and which starts at the point of application when directly operated by the driver (or another person) or at the point where a control signal is fed into the braking system when indirectly operated by the driver or when operated without his or her intervention, and which may terminate either at the point where the energy necessary to produce the application force is distributed or where a part of that energy is distributed for the control of that application force Note 1: The control signal may be conveyed within the control device by, for example, mechanical, pneumatic, hydraulic or electrical means, including the use of auxiliary or non-muscular energy. Note 2: The control device may be operated by ——the direct action of an individual, either by hand or foot, ——the indirect action of the driver or, in the case of a towed vehicle only, without any action, ——variation of the pressure in a connecting pipe or of the electrical signal in a cable between the towing and towed vehicles, either at the time of operation of one of the braking systems of the towing vehicle or in the case of a failure, and ——the inertia of the vehicle or by its weight or that of one of its constituent elements (e.g. by approach or separation of the towing and towed vehicles or by the lowering of a constituent element). 5.4 transmission device part of a braking system which transmits the energy distributed by the control device, starting either at the point where the control device terminates or at the point where the energy-supplying device terminates, and terminating at the point where the brake starts Note: The transmission device may, for example, be of mechanical, hydraulic, pneumatic (pressure above or below atmospheric), electric or combined (e.g. hydromechanical, hydropneumatic) type. 5.5 brake parts of a braking system in which the forces opposing the movement or tendency to movement of the vehicle are developed 5.5.1 friction brake brake in which the components attached to a fixed part of the vehicle are applied by the actuation force against one or more components attached or coupled to a wheel or an assembly of wheels Note: The friction brake in which the effect of an actuation force or forces is increased by the friction forces is called a “self-servo” type. 5.5.1.1 drum brake friction brake in which the friction forces are produced between the components attached to a fixed part of the vehicle and the internal or external surface of a drum 5.5.1.2 disc brake friction brake in which the friction forces are produced between the components attached to a fixed part of the vehicle and the faces of one (more) discs 5.5.1.3 Friction brake components 5.5.1.3.1 brake lining assembly component of drum brake or disc brake which is pressed against the drum or disc, respectively, to produce the friction force 5.5.1.3.1.1 shoe assembly brake lining assembly of a drum brake 5.5.1.3.1.1.1 leading shoe assembly shoe assembly on which the effect of the actuation force is increased by the friction forces generated between the rotating drum and the brake lining 5.5.1.3.1.1.2 trailing shoe assembly shoe assembly on which the effect of the actuation force is decreased by the friction forces generated between the rotating drum and the brake lining 5.5.1.3.1.2 pad assembly brake lining assembly of a disc brake 5.5.1.3.2 attachment carrier component of a brake lining assembly to which the brake lining is attached 5.5.1.3.2.1 shoe component of a shoe assembly which carries the brake lining 5.5.1.3.2.2 back plate component of a pad assembly which carries the brake lining 5.5.1.3.3 brake lining friction lining friction material component of a brake lining assembly 5.5.1.3.4 lining profile circumscribed line around the lining rubbing surface area 5.5.1.3.5 Brake adjustment devices 5.5.1.3.5.1 manual brake adjustment device brake adjustment device that allows an operator to manually adjust the running clearance between linings or pads and drums or discs when wear and tear occur on these components during service 5.5.1.3.5.2 automatic brake adjustment device brake adjustment device that maintains a running clearance between linings or pads and drums or discs within established tolerance bands when wear and tear occur on these components during service 5.5.2 positive engagement brake brake in which non-rotating elements of the vehicle prevent, by positive engagement, the movement of components attached in a permanent manner to a wheel or an assembly of wheels Note: Positive engagement brakes are normally only applied when the vehicle is stationary (lock). 5.5.3 retarder energy transformation means used to provide an endurance braking function independent of the friction brakes Note: There are two main categories of retarders: primary retarder and secondary retarder. These categories cover the types of retarder defined in 5.5.3.2, except for the aerodynamic retarder, which is in a category of its own. 5.5.3.1 Categories of retarder 5. 5.5.3.1 primary retarder retarder located on the drive train of a motor vehicle at the engine side of the gearbox (torque converter) 5.5.3.1.2 secondary retarder retarder located on the drive train of a motor vehicle between the gearbox (torque converter) and the drive axle(s) Note: All retarders connected to non-driven axles are secondary retarders. 5.5.3.2 Types of retarder 5.5.3.2.1 engine brake means whereby the engine drag resulting from the reduction of the fuel input and the throttling of the induction air supply whilst the engine is linked to the driving wheels retards the vehicle 5.5.3.2.2 engine retarder mechanism in which an increased retarding effect is obtained by changing the valve timing to increase the internal resistance (drag) of the engine 5.5.3.2.3 exhaust retarder mechanism in which an increased retarding effect is obtained by blocking the flow of the exhaust gas to increase the internal resistance of the engine 5.5.3.2.4 electronic traction motor retarder mechanism in which the electric traction motor, linked to the driving wheels, exercises a retarding effect on the moving vehicle, for example, by functioning as a current generator 5.5.3.2.5 hydraulic retarder mechanism in which a retarding effect is obtained by using components linked, usually to the driving wheels, and which pumps a fluid in a restricted circuit 5.5.3.2.5.1 hydrodynamic retarder hydraulic retarder in which power is absorbed by dissipating the kinetic energy of the pumped fluid 5.5.3.2.5.2 hydrostatic retarder hydraulic retarder in which power is absorbed by causing the pumped fluid to develop a considerable pressure in the circuit 5.5.3.2.6 Electric retarders 5.5.3.2.6.1 electromagnetic retarder mechanism in which a retarding effect is obtained by the action of an electromagnetic field on a rotating component (eddy current, hysteresis) linked to one (more) wheel(s) 5.5.3.2.6.2 permanent-magnetic retarder mechanism in which a retarding effect is obtained by the action of a permanent magnetic field on a rotating component (eddy current, hysteresis) linked to one (more) wheel(s) 5.5.3.2.6.3 regenerative braking retarder retarder which, through the generation of braking torque by electrical means, recovers kinetic energy from the vehicle in order to store it in a battery 5.5.3.2.7 mechanical regenerative braking retarder retarder which, through the generation of braking torque by mechanical means, recovers kinetic energy from the vehicle in order to store it in an energy reservoir 5.5.3.2.8 aerodynamic retarder mechanism in which a retarding effect is obtained by causing an increase in the air resistance, for example, by the deployment of movable surfaces 5.6 Energy or control transmission lines for fluids 5.6.1 pipe / tube line, either flexible or rigid, for transmission of hydraulic or pneumatic energy 5.6.1.1 rigid pipe line of permanently-formed shape linking two parts fixed relative to each other Note: Any deformation suffered by such a connection is permanent. 5.6.1.2 semi-rigid pipe line of non-permanent shape linking two parts fixed relative to each other 5.6.1.3 flexible pipe line of non-permanent shape linking two parts which are moveable with respect to each other Note: A coiled pipe is a special version of a flexible pipe. 5.6.2 Classification according to function 5.6.2.1 internal supply line line linking the energy source or the energy reservoir to the device controlling the energy flow (e.g. brake valve) 5.6.2.2 actuating line line linking the device controlling the energy flow (e.g. brake valve) to the device converting the energy of the agent into mechanical energy (e.g. brake cylinder) 5.6.2.3 pilot line line linking a control device (e.g. brake valve) to another control device (e.g. relay valve), the energy flow serving only as a signal to the second control device 5.6.3 Pneumatic piping connecting braking equipment between towing vehicle and trailer(s) 5.6.3.1 supply line means of supplying energy from a towing vehicle to the energy reservoir of the towed vehicle 5.6.3.2 control line means of connecting the signal which controls braking to devices which adjust the braking level in the trailer accordingly 5.6.3.3 common supply and control line (single line braking system) line serving equally as energy supply and control line 5.7 coupling head; glad hand device to connect or disconnect internal supply line, actuating line and pilot lines 5.8 braking force proportioning device device whose function is to modify, automatically or otherwise, the braking force for the purpose of achieving the required braking distribution 5.8.1 load-sensing device device which automatically adjusts the braking force on one or more wheels of the vehicle in accordance with the static or dynamic load on those wheels 5.8.2 pressure-sensing device device which automatically adjusts the braking force on one or more wheels of the vehicle with a designed relationship to the input pressure 5.8.3 deceleration-sensing device device which automatically adjusts the braking force on one or more wheels of the vehicle in accordance with the deceleration of the vehicle 5.9 warning device optical or audible device warning the driver when certain conditions of operation of the braking system or systems have become critical, have failed or require maintenance 5.10 Electronic devices 5.10.1 sensor component responsible for sensing the conditions of rotation of the wheel(s) or the dynamic condition of the vehicle, and for transmitting this information to the controller 5.10.2 controller component responsible for evaluating the information supplied by a sensor or sensors and for transmitting control signals to the modulator 5.10.3 modulator component responsible for modulating the pressure and therefore the braking force in direct response to control signals received from the controller 5.11 supplementary device (towing/towed vehicles) part of a braking system on a towing vehicle intended for the supply of energy to, and control of, the braking system on the towed vehicle and which comprises the components between the energy-supplying device of the towing vehicle and the supply line coupling head (inclusive), and between the transmission device(s) of the towing vehicle and the control line coupling head (inclusive) 5.12 actuation mechanism all mechanical components of the transmission device linking an operating element (e.g. Cylinder) to the brake 5.13 auxiliary release device (spring brake actuator) device allowing the removal of the brake input force resulting from the spring brake actuator when its feed pressure has fallen below the hold-off pressure, for example, as a result of a failure, and which is operated only to allow the vehicle to be moved after such a failure has occurred 5.14 auxiliary device consuming energy any device in a vehicle not belonging to a braking system but which uses the same energy source(s) and/or energy accumulators as the braking system circuits 6 Driver supporting control braking systems 6.1 anti-lock braking system; ABS system which automatically modulates the pressure producing the braking forces at the wheels to limit the degree of wheel slip 6.1.1 Types of wheel control 6.1.1.1 individual wheel control ABS control where the pressure producing the braking force at each wheel is individually modulated 6.1.1.2 multi-wheel control ABS control where the pressure producing the braking force at a group of wheels is modulated by a common command 6.1.1.2.1 axle control multi-wheel control where the group of wheels controlled by the common command is restricted to those on a single axle 6.1.1.2.2 side control multi-wheel control where the group of wheels controlled by the common command is restricted to those only on one side of the vehicle 6.1.1.2.3 diagonal control multi-wheel control where the wheels diagonally opposite each other on the vehicle are controlled by a common command 6.1.1.2.4 combined multi-axle control multi-wheel control where all the wheels of a multiaxle combination are controlled by a common command 6.1.1.2.5 modified axle / side control multi-wheel control, based on a combination of the modified axle and side controls, in which the common command is derived from sensor signals in which the selection made is changed dynamically 6.1.1.2.6 modified individual wheel control individual control in which the pressures producing braking forces at each wheel on an axle are individually modulated but control decisions governing these pressures additionally take into account data from the opposite wheel Note: The objective is to reduce the lateral pull on the vehicle by permitting only a gradual divergence of the braking forces on split-adhesion surfaces. 6.1.1.3 Selection of sensor signals for system control 6.1.1.3.1 Dynamic selection 6.1.1.3.1.1 select-low multi-wheel control where the wheel with the lowest speed is selected to provide the signal from which the common command for the group is derived 6.1.1.3.1.2 select-high multi-wheel control where the wheel with the highest speed is selected to provide the signal from which the common command for the group is derived 6.1.1.3.2 Predetermined selection 6.1.1.3.2.1 selection by wheel multi-wheel control where the signal of a predetermined wheel controls the system for all the wheels of the group 6.1.1.3.2.2 average selection multi-wheel control where the instantaneous wheel speeds are averaged for the group and this average is used as the signal from which the common command for the group is derived 6.1.1.3.3 directly controlled wheel wheel whose braking force is modulated according to data provided by at least its own sensor 6.1.1.3.4 indirectly controlled wheel wheel whose braking force is modulated according to data provided by the sensor or sensors of another wheel or other wheels 6.1.2 Control operation 6.1.2.1 minimum control speed speed of vehicle below which the antilock braking system is no longer capable of overriding the control forces transmitted to the brakes by the driver 6.1.2.2 sensor signal information supplied by the sensor from which the wheel speed may be calculated 6.1.2.3 resolution of impulse wheel speed sensor resolution of impulse wheel speed sensor number of impulses supplied by the sensor for one revolution of the wheel 6.1.2.4 control cycle complete pressure reduction and reapplication cycle of the antilock braking system which takes place between the detection of one imminent wheel lock and the next 6.1.2.5 control frequency number of control cycles occurring per second, on a homogeneous road surface 6.2 traction control system system which improves traction and driving stability of a vehicle by preventing excessive wheel slip at its drive wheels Example: Engine torque control, brake intervention control, differential gear control, or a combination of these. 6.3 stability control system dynamic drive control system system which automatically assists the handling of a vehicle or vehicle combination in response to the degree and the direction of the steering wheel angle 6.4 brake hold and release aid hill holder system which, on activation automatically continues the application of a braking system or systems and releases the brakes in a defined way when an appropriate signal or signals indicate that the driver is attempting to move the vehicle 6.5 autonomous intelligent cruise control enhancement of standard cruise control systems which allows a vehicle to follow the vehicle in front at an appropriate distance by controlling the engine and/or powertrain and, potentially, the potential brakes 6.6 coupling force control system system whose objective is to balance automatically the braking rate of towing and towed vehicles in combination 7 Braking phenomena 7.1 Lining characteristics with potential influence on braking performance 7.1.1 glazing brake lining surface condition resembling glass Note: Glazing causes a reduction in the coefficient of friction and often results from light-duty use, i.e. repeated lightbraking applications. 7.1.2 detachment separation of lining material from its carrier 7.1.3 crack deep and narrow crack in a lining surface which is not sufficient to cause breakage or fragmentation of lining material into two or more parts 7.1.4 surface cracking shallow crack in the surface, usually present in some numbers on the same lining

Contents of GB/T 5620-2020

Foreword I 1 Scope 2 Normative references 3 Braking systems and equipment - General 4 Categories of braking system 4.1 Braking systems relating to their energy supplying device 4.2 Braking systems relating to transmission means 4.3 Braking systems relating to arrangement of transmission means 4.4 Braking systems relating to vehicle combination 5 Braking system components 6 Driver supporting control braking systems 7 Braking phenomena 7.1 Lining characteristics with potential influence on braking performance 7.2 Vehicle braking behaviour 8 Brake lining tests 9 Braking mechanics 10 Pressure 11 Additional definitions Annex A (Normative) Brake amplification factors Annex B (Normative) Evaluation of mean fully developed deceleration Bibliography Alphabetical Index